From: lschuler@cellular.uscc.com Date: Mon, 04 Jan 1999 10:30:30 -0600 Subject: Re[2]: COZY: voids >Could you sum up the pertinant comments, where possible without revealing the >so ce. Sure. Here's a summary of suggestions: 1. Weigh the item in water and compare this weight to a "known" good one. 2. Use a dime 'tap' test along the length of the item and listen for differences in the sound. 3. Use a high intensity light source to illuminate the layup and look for voids. 4. Don't worry about checking heavy glass parts provided by vendors since other folks have used these items with no reported problems yet. Larry From: Militch@aol.com Date: Mon, 11 Jan 1999 10:46:29 EST Subject: COZY: Epoxy amount to use I am working on the bulkheads (seat back right now) and would like some advice on whether I am using the right amount of epoxy.I have been squeegeeing the epoxy until only the smallest amount remains on the squeegee after a wipe, but not so much that it pulls or distorts the cloth in the layup. I get it down enough that the texture of the weave can be felt with the fingertips after it has cured. Chapter three shows a picture illustrating insufficient epoxy use, and it depicts the top layer of fiberglass "sitting" on the lower layers with epoxy in the threads, but essentially no epoxy between the strands. I don't thing I am getting it that low, and a close visual inspection shows good saturation of the top layer with epoxy. Never-the-less, you can definitely feel the weave if you run your finger tips over the cured surface. I tried peel ply on a small part of the seat back jsut to see what it felt like, and the surface it leaves behind is much smoother. The epoxy seems to fill the weave evenly, so that you can't sense the individual threads by touch. So, when I just squeegee, I definitely leave behind less epoxy than when I use peel ply, but I don't think it is as low as shown in the chapter three "too little epoxy" illustration. My test article built during chapter 3 exhibits the same surface weave texture effect as the seat back, and it came in at 11.9 oz. Since I built in on saran wrap, I found a fair amount of epoxy on the bottom surface (the one that was in contact with the saran wrap) once I let it cure and turned it over. If I had turned the test sample over during assembly and squeegeed that surface as well, I could probably have pulled another quarter or half ounce or so off, so would still have been inside the 10.5 - 12.5 oz range that is quoted. I made a test sample using some of the left over foam from the seatback. I made four test strips. I put two layups of three inch wide strips of BID on the foam. Strips one and three were laid on foam that was first micro'd. Stips two and four went directly on the foam using only epoxy. I peel plied strips 3 and 4. After a 24 hour cure, I pulled each strip off. Without using a spring guage of some kind, I had to rely on feel. I didn't sense a significant difference between any of them. They all took a pretty hefty pull to break loose. None had bonded so strongly that the foam broke or tore. The separation mainly occurred at the glass to epoxy bond, although one of the stips did come off with a few fragments of the blue foam attached. Witout a doubt though, the peel plied test articles were heavier. I could tell that just by holding them in my hands. There are definitely no air bubbles or voids in the samples I have made so far, or in the seat back. Does it sound like I am leaving the right amount of epoxy in the weave, or am I too low? Of course, if I am too low, I could just peel ply everything, but if that makes things un-neccessarily heavy, then I would rather not do that. I appreciate any comments or suggestions. Peter Militch #740 Date: Mon, 11 Jan 1999 10:50:51 -0600 From: Tom Brusehaver Subject: Re: COZY: Epoxy amount to use >I am working on the bulkheads (seat back right now) and would like some advice >on whether I am using the right amount of epoxy.I have been squeegeeing the >epoxy until only the smallest amount remains on the squeegee after a wipe, but >not so much that it pulls or distorts the cloth in the layup. I get it down >enough that the texture of the weave can be felt with the fingertips after it >has cured. Sounds pretty good. The amount I was told to shoot for is a 50-50 ratio. Weigh the glass you are gonna use, and weight the epoxy that will fill the glass, it should weigh the same. Reality, it is hard to do exactly that amount, you got your glass over sized, and it is pretty hard to wet out the whole area with that little epoxy without some practice. > Chapter three shows a picture illustrating insufficient epoxy use, >and it depicts the top layer of fiberglass "sitting" on the lower layers with >epoxy in the threads, but essentially no epoxy between the strands. This happens, like when you are doing a multi layer layup, and the layups have been really juicy, so you think, I got enough epoxy here, I not add any more on top, I'll just squeegy the juice into the top layer. Inevitably, you'll miss an area, and it'll be really easy to spot, cause the area will be white(silver) compared to the area around it that is filled. Best way to avoid this, is not to get the layers juicy, and squeegy each layer as if it will be the top layer. >I tried peel ply on a small part of the seat back jsut to see what it felt >like, and the surface it leaves behind is much smoother. The epoxy seems to >fill the weave evenly, so that you can't sense the individual threads by >touch. So, when I just squeegee, I definitely leave behind less epoxy than >when I use peel ply, but I don't think it is as low as shown in the chapter >three "too little epoxy" illustration. Peel ply will help fill the strands with excess epoxy, and can be beneficial for certain cosmetic layups. You will have a little more epoxy than the ideal layup. Typically, ideal layups are hard to get, and peel ply will absorb some excess. Builders will argue this point, saying each layup they do is ideal. Mine all aren't, and I use peel ply to help. When you do the LG bulkhead layups, and press 24 layers of glass, watch how much epoxy squeezes out of your layup, that will give you a clue how much excess you have in there. The more you practice the more you get a feel for this epoxy stuff. From: Epplin John A Subject: RE: COZY: Epoxy amount to use Date: Mon, 11 Jan 1999 11:33:00 -0600 > -----Original Message----- > From: Militch@aol.com [SMTP:Militch@aol.com] > [Epplin John A] > I made a test sample using some of the left over foam from the seatback. I > made four test strips. I put two layups of three inch wide strips of BID > on > the foam. Strips one and three were laid on foam that was first micro'd. > Stips two and four went directly on the foam using only epoxy. I peel > plied > strips 3 and 4. After a 24 hour cure, I pulled each strip off. > > Without using a spring guage of some kind, I had to rely on feel. I > didn't > sense a significant difference between any of them. They all took a pretty > hefty pull to break loose. None had bonded so strongly that the foam > broke or > tore. The separation mainly occurred at the glass to epoxy bond, although > one > of the stips did come off with a few fragments of the blue foam attached. > Witout a doubt though, the peel plied test articles were heavier. I could > tell that just by holding them in my hands. > [Epplin John A] Peter: Good job! I am a bit surprised by your results though. I have pulled several pieces apart and always get most all the micro and some foam with the glass. My general method is to squeegee each layer as dry as practical before going on the next layer. After the last layer is looking good I then apply peelply to most everything. I will add very little more epoxy to the peelply, just enough to wet it out. Some times none is needed. What I have done is weigh the peelply before application and also weigh my epoxy cup before the peelply and again after. This tells me how much more epoxy was applied. When cure is finished, I remove the saturated peelply an weigh it. In all cases I have removed more epoxy than I used for the peelply alone. Never a large amount, usually around 1 percent of the total epoxy came off with the peelply. I don't do the weigh operations on all lay-ups, just occasionally to see where I am at. One thing I did at the start of the project was to invest in a good digital scale, Acculab 300. Every batch of epoxy has been weighed on this scale, usually to the nearest .1 gram total. This has taken some time but I am sure of the ratio used. I use jug pumps with a stop on the hardener pump so there should be equal number of pumps for hardener and resin. I pump the required resin into the cup, followed by the same number of pumps of hardener. The last stroke is monitored closely for final weight. Small adjustments are made here. This gives me a double check on the ration with very little chance of a foul-up. John Epplin Mk4 #467, installing engine stuff. From: Militch@aol.com Date: Mon, 11 Jan 1999 12:53:48 EST Subject: RE: COZY: Epoxy amount to use In a message dated 1/11/99 1:37:50 PM, John Epplin wrote: > I am a bit surprised by your results though. I have >pulled several pieces apart and always get most all the micro and some foam >with the glass. My general method is to squeegee each layer as dry as >practical before going on the next layer. After the last layer is looking >good I then apply peelply to most everything. John thanks for your comments. I have basically been doing the same, although not with the peel ply final layer. Your approach makes sense though. I have also tended to leave the first layer a little wet, and used that excess epoxy to start the wetting of the next layer. I see however, that when I squeegee, it comes out slightly white. The MGS is usually clear in small quantities. My guess is that some of the micro gets brought up through the first layer, which I know is not good. I am very careful to scrape the micro down to the absolute minimum on the foam, so if I am picking some up through the first and second layers, it's a bit of a surprise. Still, that seems the most likely explanation. It might be the case that I am collecting some of the color off of microscopic glass particles in the fiber. I will know the answer today because I am going to lay up the engine mount hardpoints which require 22 layers of BID and no micro underneath. If the excess epoxy has a little color added, I will know for sure it's out of the glass. If not, then I will have to squeegee that micro even more - Till it screams for mercy. Peter Militch #740 Date: Mon, 11 Jan 1999 13:14:53 -0500 From: Paul Krasa Subject: Re: COZY: Epoxy amount to use > >There are definitely no air bubbles or voids in the samples I have made so >far, or in the seat back. Does it sound like I am leaving the right amount of >epoxy in the weave, or am I too low? Of course, if I am too low, I could just >peel ply everything, but if that makes things un-neccessarily heavy, then I >would rather not do that. > >I appreciate any comments or suggestions. > >Peter Militch #740 > If you fully wet out the glass prior to squeegeeing out the epoxy, it is very difficult to produce a "dry" layup. A visual inspection will tell you if you are dry. If you do not see white specks or obvious voids then the layup is good. This assumes you are using EZ-poxy. With a clear epoxy it is much more difficult to inspect for dryness or voids. Also go back and check the archives because in years past we have had a number of disscussions on this subject. Every builder goes through this questioning, and by the end of the project, you will be able to tell if the layup is too wet or dry before the epoxy starts to set up. Good luck and keep building. Paul Long EZ 214LP From: "Chris Byrne" Subject: COZY: Layups Date: Fri, 5 Feb 1999 10:21:17 +1100 While were on the subject of layups. I am using MGS L335, humidity never above 70% and temp around 75 F (24C). I stipple and squeegee like crazy, and use a hair dryer at times. But when I pull the peel ply off I have numerous white flecs in the layup, at times greater than the amount allowed. On one of the LDG Gear bulkheads I sanded all the glass off and started again, being even more particular in the wetting out. This time I did not peel ply the entire section, and I spent considerable time wetting out the peel ply on the section that was peel plied. Upon curing, off came the peel ply and guess what, same white flecs, but the area that was not peel plied was perfect. I have noticed this on many occasions since, the area that is peel plied looks like a poor layup while the area left in its original glass/epoxy state looks great. What am I doing wrong or is this a common problem. Seems to me that as the peel ply is much finer it is very hard to remove all the air from under it. Chris Byrne PS Mark if my postings still contain all the junk at the end let me know. From: cdenk@ix.netcom.com Date: Thu, 4 Feb 1999 18:31:19 -0600 (CST) Subject: Re: COZY: Layups Chris writes I have been known to use a pin or exacto blade point to make small holes in pealply to allow air to escape. Sometimes more heat works, and squeege toward edge of pealply, moving air. From: cozy623@juno.com Date: Thu, 4 Feb 1999 18:30:52 -0700 Subject: Re: COZY: Layups Same problems here. I have found that with MGS keeping the shop very warm and very careful application of peelply solves it. Once the peel ply is wet it doesn't want to let the air out so I just make sure that it is right the first time down and NEVER pull it back up. When it is set down dry you can stipple it down gently and the air will come up through. Once it is wet if you get air under it you have to push the air to the side or it will just get shoved into the layup. Jeb From: "Nat Puffer" Subject: Re: COZY: Layups Date: Fri, 5 Feb 1999 07:30:45 -0600 Cozy builders, Burt Rutan recommended against using peel-ply over all of a layup, because he said that if a builder covered up the layup, he couldn't see whether he was leaving air in it and not using enough epoxy. The other argument is that if a builder does it correctly, the layup is more compact and requires less fill when peel ply is used. I like to think of it as a poor-mans vacuum bagging. Nat ---------- > From: bil kleb > To: cozy_builders mailing list > Subject: Re: COZY: Layups > Date: Friday, February 05, 1999 8:59 AM > > Chris Byrne wrote: > > > > Upon curing, off came the peel ply and guess what, same white flecs, but the > > area that was not peel plied was perfect. > > i had this happen the first time i peel-plied too. check the archive > subjects `peel_ply' and `layups'. for example, the following has a good > discussion of exactly your problem: > > http://cozy.canard.com/mail_list/topics96/peel_ply.txt > > i found that i have to be patient, use a monokote heat gun, and employ > gentle pressure with a brush or squeegee to avoid the flecks. > (occasionally i also have to add a bit more epoxy if the layup is > particularly dry or starting to "go off".) > > -- > bil From: lschuler@cellular.uscc.com Date: Fri, 05 Feb 1999 08:43:18 -0600 Subject: Re: COZY: Layups Chris Byrne wrote: >snip >I have noticed this on many occasions since, the area that is peel plied >looks like a poor layup while the area left in its original glass/epoxy >state looks great. One of the things that peel ply can do for you is to provide a means to fill in the weave valleys (between the yarns) that would otherwise not get filled (within normal glass/epoxy ratios). Laying the peel ply over a layup may result in an initial wet-out appearance, but the peel ply actually bridges those valleys and due to capilary action only 'appears' to be properly wet. I have had same concerns/problems, especialy with the nearly clear 2427 epoxy of days gone by. I found that treating the peel ply as another layer of glass, and adding plenty of epoxy as I would glass, then squeegeeing it religiously works perfectly. This layer is usually done at the end of the session and the epoxy is begginning to thicken a bit. The hair dryer and excess epoxy works wonders and allows me to literally replace the air in the tiny valleys with epoxy, pushing the air to the edge of the layup (along with excess epoxy of course). Whenever I "over' squeege (too hard or too much) I end up pushing the peel ply into the valleys, only to have it pop up and leave the tiny air pocket underneath. Finess and practice seems to have paid off. My front seat back, for example really stinks. It's solid enough and the glass is properly filled, but lots of the 'surface' spots you describe which "look" worse than if I had not used peel ply. That has been sanded to smooth the surface a bit and I'll end up filling it with micro when I finish the inside of the fuselage much later. Hope this helps. Larry Schuler From: Militch@aol.com Date: Wed, 3 Feb 1999 00:14:10 EST Subject: COZY: One more layup question As I move along on the bulkheads, I still feel concerned about the quality of my layups. I am using the MGS 285 epoxy and like it a lot. I try to get my basement workshop as warm as possible for the layups, but even with my 100,000 btu / hour household furnace dumping its full output into the basement, I don't get much better than 75 - 77 degrees. (25 C which MGS says is ok) Too much thermal inertia I guess. I work under some heat lamps setup over the bench to add extra heat to the material and the epoxy, and it all sets in the specified time, so I think I am in fairly good shape there. I notice that when I do the layups, I will get small segments of the fiber threads (perhaps an eighth of an inch long) at random intervals that remain white after I pour on the epoxy, stipple it in, squeegee it, and do just about anything else I can to it. Most of the cloth wets out with no help from me, but getting those little white flecks to wet out is very difficult. I can stroke and stipple the affected portion a dozen times with the brush before it appears to succumb, but after cure, I can still see those flecks. If lay peel - ply over the affected area, it all wets out well. No marginal dry spots. My layups are coming in slightly heavier than the average weights reported by others on Mark's web page, so I am not scrimping on the epoxy. It's almost as if there are contaminants on the glass that simply prevent wetting, but I see this about equally on my uni and bid - two separate rolls of material. I keep my cloth in a sealed cabinet to prevent contamination and avoid touching it to the maximum extent practical. I don't want to convey the idea that the whole layup is one big non-wetted disaster. On the aft landing gear bulkhead, with a total of 12 layers of uni and bid, I would say the white flecks obscure perhaps 2 or 3 percent of the total surface. Spread over all those layers, that is probably pretty good. The trouble is, I don't know for sure, and I am going to hold a Jim Jones kool -aid party if I have to reject all the work I have done to date. I have ordered the "Burt Rutan composites instruction tape from Wicks, and plan to take some parts along to my first EAA chapter meeting for review by the experts, but any additional input or suggestions would be welcome. The plans are great and the assembly is fun, but I need to be sure I am doing it right. Thanks, Peter Militch #740 Date: Wed, 03 Feb 1999 09:07:29 -0500 From: bil kleb Subject: Re: COZY: One more layup question Militch@aol.com wrote: > > I notice that when I do the layups, I will get small segments of > the fiber threads (perhaps an eighth of an inch long) at random > intervals that remain white after I pour on the epoxy, stipple > it in, squeegee it, and do just about anything else I can to it. i experience the same thing if i try to do layups when the glass is wet, i.e., check the humidity of your glass storage area and the air that you're working in. i have heard that some people keep a light bulb in their glass storage cabinet or even bake their glass for this very reason... i got a temperature/humidity gauge from the local home-supply store for about $25. i have trouble with layups when the humidity is over 70% or so. during the humid summers around here (tidewater virginia) i typically move my glass inside the day before to dry out. also, remember that the kerosene heater is pumping all sorts of water into the air: it is on the order of 1 gallon/hour according to a recent thread in the rec.aviation.owning newsgroup. (i haven't bothered to check their chemistry/math.) on the other extreme, i also get these unwettable bits if i literally sweat on the layup. :) -- bil From: cozy623@juno.com Date: Wed, 3 Feb 1999 11:44:16 -0700 Subject: Re: COZY: One more layup question I keep my shop at 82 degrees when I am doing a layup. At this temp I only have the problem you are talking about if I try to use a cup of epoxy for too long. I use mgs L335. It is sometimes hard to tell when the epoxy is getting close to the end of its pot life. I now pay VERY close attention to how runny it is staying. Don't try to push it. I can look at some of my layups and remember that "oh yeah, that is where I had to mix a new batch". Somewhere in the plans or something it says to only mix as much epoxy as you can use RIGHT NOW. Jeb From: cdenk@ix.netcom.com Date: Wed, 3 Feb 1999 17:08:44 -0600 (CST) Subject: Re: COZY: One more layup question I think their is such a thing as too warm a shop for layups. Warm might be OK for smaller layups that can be done quickly. But for the larger layups like a fuselage or wing, maybe 70 - 75 might be better. BUT use the hair dryer locally when wetting out and working out the excess epoxy. Date: Wed, 03 Feb 1999 22:53:44 -0500 From: "Marc J. Zeitlin" Subject: Fwd: COZY: One more layup question Peter Militch writes; >.....I would say the white flecks obscure perhaps 2 or 3 percent of the >total surface. Spread over all those layers, that is probably pretty good. >The trouble is, I don't know for sure.... Of course you do. Go to Chapter 3, page 10, and read the "Quality Control Criteria" section. Look for "Dryness Criteria". Up to 10% of any given 6"x6" area can have the "flecks" or air bubbles, and still be good. If you're at 2% to 3%, you've got no worries. -- Marc J. Zeitlin marcz@ultranet.com http://www.ultranet.com/~marcz/ From: Militch@aol.com Date: Thu, 4 Feb 1999 13:40:36 EST Subject: Re: Re: COZY: One more layup question In a message dated 2/3/99 11:11:28 PM, cdenk@ix.netcom.com wrote: >I think there is such a thing as too warm a shop for layups. Warm might be OK >for smaller layups that can be done quickly. But for the larger layups like a >fuselage or wing, maybe 70 - 75 might be better. BUT use the hair dryer >locally when wetting out and working out the excess epoxy. This actually makes a lot of sense. I have noticed fewer problems of the type I reported when I leave the shop at around 70 degrees. This is so inconsistent with all the recommendations I have seen for working with epoxy that I just discounted the observation. I will try using a heat gun on my next layup. My wife doesn't call me "Mr. 1 800 send me more stuff" for nothing. My Harbor Freight heat gun is due in the next couple of days. Regards Date: Thu, 04 Feb 1999 14:29:57 -0500 From: "Johnson, Phillip" Subject: Re: COZY: One more layup question Militch@aol.com writes: (sorry I don't know your proper name) > I will try using a heat gun on my next lay-up. < A heat gun tend to move the air more slowly than a hair dryer and may easily cause burning of the epoxy. The hair dryer is cheaper and blasts the warm air all over the work and is more satisfactory. I have noticed that if the part is heated and then allowed to cool too much you can also draw in air as the various parts shrink at different rates. Overheating is not just a question of melting the foam so take care. BTW many of our observations discussed to date and so the epoxies we use. What works for Eze-Poxy may not work for RAF etc. For reference I use eze-poxy and the hair dryer works just fine. Phillip Johnson Date: Thu, 04 Feb 1999 15:13:52 -0500 From: bil kleb Subject: Re: COZY: One more layup question Militch@aol.com wrote: > > I will try using a heat gun on my next layup. if it is a typical heat gun, then it is not at all what you want (imho); it is too serious---way too much heat. typically people use hair dryers left over from the seventies, but as was mentioned before, a monokote "heat" gun from a hobby shop is the ideal tool for this job, e.g., http://www.towerhobbies.com/products/towr3200.html http://www.top-flite.com/accys/topr2000.html\ it has less velocity and lower (somewhat controllable) heat. i have both. i use the hairdryer only when a helper is using the monokote gun. -- bil Date: Thu, 04 Feb 1999 15:42:57 -0500 From: bil kleb Subject: Re: COZY: One more layup question bil kleb wrote: > > http://www.top-flite.com/accys/topr2000.html\ sorry, i don't know how the backslash got there... http://www.top-flite.com/accys/topr2000.html -- bil From: cdenk@ix.netcom.com Date: Thu, 4 Feb 1999 15:56:54 -0600 (CST) Subject: Re: COZY: One more layup question Hair dryer - smaller, lighter weight works fine. From: cdenk@ix.netcom.com Date: Thu, 4 Feb 1999 15:59:33 -0600 (CST) Subject: Re: Re: COZY: One more layup question Militch said (Harbor freight heat gun) Don't think so, just a cheap smaller hair dryer, I had 2 or 3 laying around, if one was troulbesome, just grab another, or leave plugged in, and grab the other as moving around. Use for nearly all layups, including ones smaller than 6" X 6". Date: Thu, 04 Feb 1999 17:21:14 -0500 From: bil kleb Subject: Re: COZY: One more layup question cdenk@ix.netcom.com wrote: > > Hair dryer - smaller, lighter weight works fine. monokote gun - even smaller, even lighter weight even works finer. -- bil Date: Wed, 03 Feb 1999 08:52:49 -0500 From: "Johnson, Phillip" Subject: COZY: RE: One more layup question You might try using a hair dryer to heat the epoxy whilst you are doing the lay-up. Use your left hand to hold the hairdryer and your right hand for the squeegee. The problem with the heat lamp is that the glass reflects the heat whilst the epoxy absorbs the heat so the area lean in epoxy takes longer to heat. The hair dryer works better than the heat lamp, but keeping the heat lamp on afterwards will accelerate the cure. (Don't overheat). I had the same problem as you. Now I can't do a lay-up without the hairdryer, my left hand doesn't know what to do otherwise. Good Luck Phillip Johnson From: cozy623@juno.com Date: Thu, 4 Feb 1999 14:21:35 -0700 Subject: COZY: More question Different epoxies are definitely different as far as what temp they like. With RAE I also kept my shop 70-75 but with MGS You can easily make whipped cream (stippling) if it is too cold. At least with a little more warmth the bubbles come out in a reasonable amount of time. Then again I am just a kook who is still experimenting. Mgs is wierd stuff compared to the RAE but I need to have a long working time when it is hot here and I have no choice about temp. (a lot of the year). Jeb Date: Thu, 04 Feb 1999 11:47:45 -0800 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: COZY: heat gun (was: One more layup question) I will try using a heat gun on my >next layup. My wife doesn't call me "Mr. 1 800 send me more stuff" for >nothing. My Harbor Freight heat gun is due in the next couple of days. > >Regards Just a small caution. A true heat gun will develop temperatures MUCH higher than a hair dryer. I have found that all the heat you could ever want (and then some) is available from the common household hair dryer. I am referring to tasks such as warming a layup to get good wetting and removal of excess epoxy, softening an edge that has gone slightly beyond optimum "leather stage" for knife trimming, etc. In general, I think a true heat gun is far too hot for this type of use. --Howard Rogers 650-926-4052 hrogers@slac.stanford.edu pager: 650-997-1089 Web Page: http://www.stanford.edu/~hrogers/index.htm New! email directly to my pager (approximately 50 word limit). Try it!: 6509971089@alphapage.airtouch.com From: "Chris Byrne" Subject: COZY: RE: Layups Date: Mon, 8 Feb 1999 22:05:36 +1100 Cozy Group I have been away for a few days, thanks for all the info. Seems as though I may have been a bit sparse with the epoxy when applying the peel ply. Have sanded the last layup and all the specs (white patches) disappear before getting into the top layer of glass, so definitely a problem with the peel ply application and not the entire layup. Once again every thing is in the archives, thanks Bil. Chris Byrne From: "Bill Kastenholz" Subject: Re: COZY: Chapter 10 Lessons Learned Date: Fri, 5 Mar 1999 03:52:34 -0500 Howard Rogers stated: I have used heavy duty aluminum foil, brown kraft paper, and visquene polyethylene, though I am a little wary of that last one, because I have felt a "waxy" feeling stuff on the surface of some of it. My personal favorite is the heavy foil... My own favorite is the #1400 vacuum bagging film ($1.50/yd) from ACS. It has the advantage of being a transparent green, so you can draw the shape of your piece in sharpie and if needed use either side. It is much sturdier than other bagging film I have seen and comes on a 54" roll so no seams or fold creases, it lies flat. Bil Kastenholz Date: Fri, 5 Mar 1999 08:12:53 -0600 From: Tom Brusehaver Subject: Re: COZY: Chapter 10 Lessons Learned > My own favorite is the #1400 vacuum bagging film ($1.50/yd) from >ACS. It has the advantage of being a transparent green, so you can >draw the shape of your piece in sharpie and if needed use either >side. It is much sturdier than other bagging film I have seen and >comes on a 54" roll so no seams or fold creases, it lies flat. I do this, but if I don't draw the shape on the back of the film, sometimes the epoxy will erase the lines. Usually the first time after a couple weeks, I'll forget, and then I got a nearly clear sheet, that I can't remember how big it was supposed to be. Also with plastic like this, I'll cut the peice twice as big as I need, then once the layers are there, I'll fold over the excess, and squeege out the excess epoxy. Works great, helps keep things light. Date: Fri, 05 Mar 1999 09:06 -0600 (CST) From: Michael Pollock Subject: Re: COZY: Chapter 10 Lessons Learned Howard Rogers wrote: >I have used heavy duty aluminum foil, brown kraft paper, and visquene >polyethylene, though I am a little wary of that last one, because I >have felt a "waxy" feeling stuff on the surface of some of it. My >personal favorite is the heavy foil... The best thing that I have used is the 2mm plastic used for covering furniture, etc. while painting a room. It is very cheap when purchasing it from Home Depot. It also peels off of the wetted fiberglass cloth without pulling the cloth from the surface you are trying to cover. I have found that the thicker, stiffer plastic pulls the cloth away from the foam on a complex curve when trying to remove it. Michael.Pollock@mci.com Flying Velocity N173DT Building Cozy MKIV #643 From: "John Slade" Subject: COZY: Chap 4 - fiberglass cloth Date: Wed, 17 Mar 1999 09:46:30 -0500 I'm just about done with Chap 4, and have a couple of observations / questions about the cloth. I get a lot of "stray fibers" floating around which have to be picked off the layup or brushed away, especially with the UND. I havent read anything about use of pinking shears to cut the cloth. Wouldn't this help avoid the ragged edges? I'd use straight scissors where the cloth edge will butt or overlap. This is only for edges which are off the layup. Also, I seem to be getting through my BID very quickly because of the 45 degree orientation cuts. If the width of cloth allows I always cut a ply in one piece, which means I have many little triangles left over. Should I be using small pieces and overlapping more? Lastly, I really enjoyed the way the 22ply hard point layup worked out using saran wrap. So, I used this techniques again on the firewall because I wanted to weight it down without the weights sticking to the layup. I noticed that I was able to squeegee a lot more epoxy out of the layup after the saran wrap layed on it. Is there any reason I shouldnt use saran wrap, except where I need peel ply? John Slade #757 From: Fritzx2@aol.com Date: Wed, 17 Mar 1999 14:25:32 EST Subject: Re: COZY: Chap 4 - fiberglass cloth John Slade asked: >I get a lot of "stray fibers" floating around which have to be picked off >the layup or brushed away, especially with the UND. I havent read anything >about use of pinking shears to cut the cloth. Wouldn't this help avoid the >ragged edges? I'd use straight scissors where the cloth edge will butt or >overlap. This is only for edges which are off the layup. I wouldn't be overly worried about the stray fibers. A UND stray fiber can keep the ply above it up off the ply below it which in the past could make an air bubble. One thing you could do as described in the plans later when doing the UND layup joining the top and bottom half of the front landing gear bulkhead is to put masking tape along the edge of a piece of UND before cutting the oversize glass and then do the layup (of course be very careful to not get the tape into the layup). When you trim the glass, you cut away all the tape. >Also, I seem to be getting through my BID very quickly because of the 45 >degree orientation cuts. If the width of cloth allows I always cut a ply in >one piece, which means I have many little triangles left over. Should I be >using small pieces and overlapping more?>> This is a personal tradeoff. The more pieces and overlaps you have the more the structure will weigh. Another thing to consider is aesthetics. You probably don't want a big bump of overlap right in the middle of your instrument panel or other highly visible place. You could fill in on either side of the overlap with micro fill but that too adds more weight. You have got to break some eggs to make some real mayo and you have got to waste some glass to make a lighter plane. You can save some of the larger pieces of BID and use them later to make the 2 inch wide 2 ply tapes you will need to join all the bulkheads to the sides and to the bottom of the plane along with other uses further down the road. John Fritz From: cdenk@ix.netcom.com Date: Wed, 17 Mar 1999 16:12:33 -0600 (CST) Subject: Re: COZY: Chap 4 - fiberglass cloth I prefer the rotary (pizza) cutter, its quick, leaves a nice edge. When getting ready to cut (I use a ping pong table) I use spring clamps to hold one edge to the table edge, insuring straight lengthwise fibers. Then at the clamp near the roll, pull the fibers tight perpendicular to the table edge, and with the other hand sweep the loose fabric away from you leaving straight fibers in both directions. Have you plastic cutting board (from fabric store) under before laying out the fabric. Use a straight edge with the pizza cutter. When preparing for a layup, cut all fabric , lay on the project, checking overlaps, fiber straightness, etc. Take a felt tip pen, mark both fabric edges and project edges on the glass, so the fabric can be correctly and quickly after mixing epoxy. From: Cozy7971@aol.com Date: Wed, 17 Mar 1999 17:22:08 EST Subject: Re: COZY: Chap 4 - fiberglass cloth In a message dated 99-03-17 10:06:01 EST, jslade@adelphia.net writes: << I get a lot of "stray fibers" floating around which have to be picked off the layup or brushed away, especially with the UND. I havent read anything about use of pinking shears to cut the cloth. >> I don't know if the pinking shears would work very well. Mi gut feel is thqt the weave is too loose. When I first started I would cut the cloth on my table so it was just a smidgen oversized. I would then fold it carefully and move it to the side. After microing the foam I would carefully unfold it. The end result was some loose threads and some difficulty with deformed cloth. It took some effort to pull the cloth to cover the foam and to get the threads straight. I now plan out my layups so that I have a bunch of similar pieces (often from different chapters. I lay everything out on my table and suspend the roll of cloth from the ceiling. After microing I simply pull th ecloth off the roll and drape it over the pieces. A few tugs and everything straightens out. I find I do waste a small amount of cloth this way but I think I get better results in my layups. Since I only have to cut the cloth a few times and I generally leave a few inches extra I rarely have prolems with loose threads. As one other fellow on this forum used to say -- your mileage may vary. No guarantees, but it works for me. Dick Finn Cozy Mark IV #46 Currently installing the nose gear door and getting ready to move the plane to the garage for final assembly. Date: Wed, 17 Mar 1999 20:53:49 -0500 From: Kent Ashton Subject: Re: COZY: Chap 4 - fiberglass cloth John Slade wrote: > > I get a lot of "stray fibers" floating around which have to be picked off > the layup or brushed away, especially with the UND John, have you tried putting down a strip of masking tape to outline the glass you want to use, then cut down the center of the tape. --Kent A. From: cdenk@ix.netcom.com Date: Thu, 18 Mar 1999 16:18:42 -0600 (CST) Subject: Re: COZY: Chap 4 - fiberglass cloth Then how do you get the tape off, if it doesn't get cut off. Its easier to cut dry fabric on the table, than messy with epoxy. Date: Fri, 19 Mar 1999 10:39:02 -0800 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: Re: COZY: Chap 4 - fiberglass cloth >Then how do you get the tape off, if it doesn't get cut off. Its easier to >cut dry fabric on the >table, than messy with epoxy. You are absolutely correct. It gets cut off. I use this same method for almost everything I do. I lay out my pieces on the glass cloth with a sharpie pen, with plenty of room around the perimiter. I then use 3/4 tape (masking, or whatever) all around the parts. I cut the tape right down the middle, which gives me pieces with no loose or unraveling threads. I then wet them out, either on kraft paper or directly on the foam, etc., depending on the type of parts. In either case, the wet cloth extends on off the edges of the part, and I sicissor-trim after it's wet. This process sounds more lengthy than it really is, and the neatness factor more than makes up for the little bit of time it takes to use the tape. Howard Rogers From: "Denis Thomassin" Subject: COZY: Weet trimming Date: Thu, 25 Mar 1999 09:06:44 -0500 Hi every one! I am just ending chapter 4, it took me 6 months. My wife call it me next millenium project :). While I was working on the landing gear bulkhead I realised that weet trimming the bulkhead after a 3 hours cure - not dry still sticky - the edge of the piece about 1/8 wide become white, like as it was delaminating. I never faced this behavior with they others bulkheads. Is this because the landing gear bulkhead is mostly laminated with UND clothe?. Oooopsss!!!! Last weekend I laminated the upper longeron. This morning I went trought the FAQ for chapter 5. And now I am anxious to see if i made them lounger enough.... In the FAQ there is also a solution to add a couple of inchs if needed, it must be a commun mistake. Next time I will read the FAQ before not after.... By kind for my english I am more at ease with Molière.... Denis Thomassin, Montreal, Canada 705. From: Fritzx2@aol.com Date: Thu, 25 Mar 1999 18:37:34 EST Subject: Re: COZY: Weet trimming Denis Thomassin asked: >While I was working on the landing gear bulkhead I realised that weet trimming the >bulkhead after a 3 hours cure - not dry still sticky - the edge of the piece >about 1/8 wide become white, like as it was delaminating. I never faced this >behavior with they others bulkheads. Is this because the landing gear bulkhead is >mostly laminated with UND clothe?. I have a few suggestions. First, with the new glass layup on top of the foam press down from above with the knife. While you are lifting the knife back up, don't push on the glass because that will tend to try to separate the glass layers from each other and also try and lift the glass off the foam below, both of which you want to avoid. Also, try waiting a little longer so that the epoxy is stiffer. That may help. Maybe a sharper knife would help. Where is the white area, in the glass above the foam along the edge of the part or in the glass that is overhanging the foam? The layers of glass in the white area are separating and that is not good. If it is only 1/8" wide of white area along the edge of the part then you probably don't have to redo the part but it is not good to ever make the glass separate and make a white area. If you still have a problem with cutting the partially cured glass, then wait until the glass is cured and then cut off the extra glass. It is more work to cut the glass after it has cured but at least you won't be damaging the part. John Fritz fritzx2@aol.com Date: Thu, 25 Mar 1999 21:10:25 -0500 From: "Marc J. Zeitlin" Subject: Fwd: COZY: Weet trimming Denis Thomassin wrote; >...... wet trimming the >bulkhead after a 3 hours cure - not dry still sticky - the edge of the piece >about 1/8 wide become white, like as it was delaminating. I never faced this >behavior with they >others bulkheads. Is this because the landing gear bulkhead is mostly >laminated with UND clothe?. While the UND cloth does act a bit differently than the BID, I think that maybe you just didn't wait long enough before doing the trimming (especially up there in the cold north country :-) ). I generally don't wet trim (I just wait until it's cured and cut it with a hacksaw blade in a small handle), but when I do, I wait until the layup is very stiff, and make sure that I use a VERY sharp utility knife - this is critical. A dull knife will pull at the cloth, and can cause it to absorb some air. I think you just need to wait a little longer before doing the trimming - give it a few more hours and see how it goes. -- Marc J. Zeitlin mailto:marcz@ultranet.com http://www.ultranet.com/~marcz/ Date: Thu, 25 Mar 1999 21:40:51 -0500 Subject: COZY: Cozy: Wet Trimming comment From: Dana Hill To any of the beginning builders re: above subject. I have found that at times, when I have been caught with a dull razor, inconveniece waiting for proper degree of cure, etc., I put off doing the final glass trimming until the layup has fully cured. With the use of a carbide embedded jig saw blade (no teeth, sortof smooth) trimming a cured layup flush and cleanly is no problem. However keep in mind that there are (or will be) times where access for a jigsaw is really not available. my meager 2 cents worth :-) Dana Hill #676 ___________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com/getjuno.html or call Juno at (800) 654-JUNO [654-5866] Date: Thu, 25 Mar 1999 22:07:26 -0600 (cst) From: "obrien.11985" Subject: Re: Fwd: COZY: Weet trimming I normally wait for the part to cure, then trim within about 1/4in using a hacksaw blade. I then use my sureform (I have several different sizes and shapes) to do the final trimming. A little messy but for me it's quicker, I get a clean/sharp/exacting edge, and I have yet to damage the glass or part using this method. Just my two-cents worth..... From: "Mike Caine" Subject: Re: COZY: Weet trimming Date: Thu, 25 Mar 1999 22:43:35 -0500 A technique that I've found helpful for trimming after cure is to locally heat the edge I'm about to cut with a hairdryer. If it's the next day, or even two days after cure, you can get the glass soft enough to cut with a sharp utility knife. I usually heat about 8-12 inches of the edge at a time. Since you're only heating the glass locally, you want the hairdryer very close to the portion you intend to cut. Of course, if you're working with the blue foam, you have to be careful not to get things too hot... BTW, I think it was Jeff Russell who taught me this technique, and it has worked very well for me. Mike Date: Fri, 26 Mar 1999 13:17:22 -0500 From: Bulent Aliev Subject: Re: Fwd: COZY: Wet trimming I found out the hard way that if you press the knife away from the foam when trimming, you may pull the partially cured glass off the foam. Try to slide the knife edge in one direction. If you see waxy residue build up on the blade, you should wait a bit longer for trimming. If you miss the wet trimming stage, just use a hacksaw blade on the fully cured part. Bulent Date: Mon, 29 Mar 1999 08:20:20 -0800 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: Re: Fwd: COZY: Wet trimming >I found out the hard way that if you press the knife away from the foam >when trimming, you may pull the partially cured glass off the foam. Try >to slide the knife edge in one direction. If you see waxy residue build >up on the blade, you should wait a bit longer for trimming. >If you miss the wet trimming stage, just use a hacksaw blade on the >fully cured part. >Bulent I found that I was driving myself crazy trying to guess the exact time to knife trim, especially when the shop was cooling off at night, and I wanted to sleep in a bit the next morning :-) If the cure went a bit too far, it was easy to bring it back to leather stage with a bit of hair dryer. It it does go beyond this, and I was forced to use the hacksaw blade, I learned that it pays to be very careful on the "up-stroke", or delamination could occur that way, as well. cheers Howard Rogers From: SBLANKDDS@aol.com Date: Mon, 29 Mar 1999 22:35:21 EST Subject: COZY: Re: delamination from foam Was the wing "Hard Shelled"? I would suspect this or possibly a very poor layup with a bubble that was never detected. Recheck everything!! There is always a cause. I would cut open a large inspection port in the delaminated area, and visually inspect the foam surface, and the glass surface before it is scraped, to see where the bond failed. This may reveal something about technique. Even if they jacked it up by that spot, the outer layer would show stress, not delamination. Final repair - Cut back past the delaminated area, add pour foam, sand for contour and then redo the layup extending onto good glass as per the instructions for repairs. Simply adding pour foam through a hole will cause a lump, with uncontrollable voids. Future sanding would be through the structure of the glass. Steve Date: Mon, 17 May 1999 08:25:54 -0700 From: hrogers@slac.stanford.edu (Howard Rogers) Subject: Re: COZY: MGS Epoxy-first look Ray, Good to hear all the positive stuff about MGS. Two suggestions: 1. Don't use waxed paper. The wax CAN contaminate the epoxy (that's why we use UNWAXED mixing cups). Try foil, saran wrap, heavy visquene, etc. 2. If your layup goes a little long for knife trim, don't despair and reach for your hacksaw blade till you try a little hair dryer. It is frequently possible to bring back that "stick of gum" stage just long enough for the knife-trim. It works! Howard Rogers --Howard Rogers 650-926-4052 hrogers@slac.stanford.edu pager: 650-997-1089 New! email directly to my pager (approximately 50 word limit). Try it!: 6509971089@alphapage.airtouch.com From: cdenk@ix.netcom.com Date: Mon, 17 May 1999 16:23:03 -0500 (CDT) Subject: Re: COZY: MGS Epoxy-first look hrogers said I have used mainly wax paper, But, I'm not sure any are a good idea, as far as I know all of these thin plastics are extruded or rolled between a set of rollers, and there is a release agent (wax or oil, etc.) required. It is a small quantity, but has become an issue on baby bottles and toy lately. What I would like to hear, but AM NOT QUALIFIED to say is with mixing cups, the scraping of the mixing stick and much movement of liquid, along with thick wax coatings can result in contamination of the epoxy. With the use of thin materials as an aid to positioning and cutting the wet cloth, the quantity per square inch of contact surface along with a minimum of movement results in an acceptable bond of the new material. There have been many aircraft built using wax paper over many years, and haven't heard any bad effects. From: ZeroGCorp1@aol.com Date: Mon, 17 May 1999 21:02:58 EDT Subject: Re: COZY: MGS Epoxy-first look In a message dated 5/17/99 11:28:33 AM Central Daylight Time, hrogers@slac.stanford.edu writes: > Good to hear all the positive stuff about MGS. Two suggestions: > 1. Don't use waxed paper. The wax CAN contaminate the epoxy (that's why > we use UNWAXED mixing cups). Try foil, saran wrap, heavy visquene, etc. > actually, so long as you are not stirring it up (as in a cup) the waxpaper in no problem to use. It is similar to use of a "mold release" on a molded part-designed so that epoxy will not stick. But, you wouldn't want to mix it up in the resin. The problem in the cup is that you deliberately scrape the sides to be sure to get it mixed and it then mixes with your epoxy.... > 2. If your layup goes a little long for knife trim, don't despair and > reach for your hacksaw blade till you try a little hair dryer. It is > frequently possible to bring back that "stick of gum" stage just long > enough for the knife-trim. It works! Thanks howard.... I should add that to my standard test...how long I can soften it for a knife trim with a hair drier. That would be handy to know if I let it run cure too long. I'll experiment a little with this. Ray Ray From ???@??? Wed May 19 23:00:52 1999 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id IAA15980 for ; Wed, 19 May 1999 08:14:06 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id HAA17619 for cozy_builders-list; Wed, 19 May 1999 07:05:51 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from imo15.mx.aol.com (imo15.mx.aol.com [198.81.17.5]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id HAA17614 for ; Wed, 19 May 1999 07:05:49 -0400 From: ZeroGCorp1@aol.com Received: from ZeroGCorp1@aol.com (8065) by imo15.mx.aol.com (IMOv20) id hDFCa13192 for ; Wed, 19 May 1999 07:51:40 -0400 (EDT) Message-ID: Date: Wed, 19 May 1999 07:51:39 EDT Subject: COZY: First Lay-up questions. To: cozy_builders@canard.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Mailer: AOL 4.0 for Windows 95 sub 13 Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: ZeroGCorp1@aol.com X-UIDL: 7bc137b0ff493103b18d923a07cdf9ba Finished a first layup (finally) on the seat back and I have a few questions. I seemed to have a lot of waste glass on this piece due to how I cut it...can anyone share (if you remeber) how you layed this out? Is there a prefered method for storing this scrap UND so that you can use it on smaller layups? I hate to have it lay around only to get damaged and ultimately thrown away. Suggestions appreciated. On to Knife trim...I trimmed at about 5:00 a.m (lay up started at 6:00 p.m. finshed at 8:00 pm). The MGS Epoxy was at perfect cure for this so I didn't need to use the hairdryer trick. My question is that it seemed to pull away a bit from the foam. I know this foam gets cut out in the next step, but for lay-ups that don't is this usual? I have a brand new razor. Other than that, everthing went smooth. Watch out John, you'll be looking at my web page before long ;^) Ray Cronise CZ#770 From: "John Slade" Subject: Re: COZY: First Lay-up questions. Date: Wed, 19 May 1999 09:44:12 -0400 Ray, >I seemed to have a lot of waste glass on this piece due to how I cut it...can >anyone share (if you remeber) how you layed this out? Is there a prefered >method for storing this scrap UND so that you can use it on smaller layups? You will have lots of scraps, large and small. Cloth is cheap. Dont worry about it. I keep a cardboard box (with a lid) for scraps. Don't put anything in there if it has any dust, dirt or epoxy on it. Later, you will use lots of these scraps in small layups. > >seemed to pull away a bit from the foam. When possible I put the layup over a hard surface for trim. This helps you get a straight trim and gives the glass nowhere to go. If this isnt possible, trim downwards toward the foam, not up. If seperation is happening a lot you may be jumping the gun on knife trim time. >I know this foam gets cut out in the next step It does? >Watch out John, you'll be looking at my web page before long ;^) I look forward to it. regards, John Slade From: Don Bowen Subject: COZY: RE: First Lay-up questions Date: Wed, 19 May 1999 08:13:28 -0700 Ray Cronise wrote: Is there a preferred method for storing scrap UND..... Hi Ray, Just my 2 cents worth here. I use the large size "zip lock" plastic freezer bags to store my scrap glass cloth. It keeps the dirt and other contamination off the glass and keeps the loose glass strands from getting all over the place. The bags are clear, so you can tell if you have UND or BID without opening it up. I am sure there are other methods of storing glass that work just as well. Have fun with your project. Best Regards, Don Bowen Cozy Mk IV s/n 440 From: lschuler@cellular.uscc.com Date: Wed, 19 May 1999 09:31:55 -0600 Subject: Re: COZY: First Lay-up questions. Ray Cronise wrote: >I seemed to have a lot of waste glass on this piece due to how I cut it...can anyone share (if you remember) how you laid this out? Expect some 'waste' both BID and UNI along the way. You could futz with getting each cut piece perfectly using every square inch of material, but what's your time worth. If you have ever don sewing or seen pattern work done, a bit of waste is normal to that activity as well. Many quilts are made of scraps from dress making... >Is there a preferred method for storing this scrap UND so that you can use it >on smaller layups? I fold/roll excess pieces and put them in covered boxes. One for UNI and one for BID. I visit these boxes first if there is a smaller layup to do. The 2" wide BID corner plies called for all over the place (a bit later for you) can easily be made from BID scraps. Just remember, when a longer strip is needed and all you have is short pieces to overlap the pieces about 1". When you get to the BIG layups like fuselage etc, you will be chopping off and saving some fairly large excess pieces. Hang in there. You'll be fine. Lots of folks, including me, try to pinch a few too many pennies in material early on and create extra work. Much easier and less stressful to just cut the stuff and accept the excess as being usable somewhere down the road. Just keep the pieces clean and dust free; just like you do with the rolls. >My question is that it seemed to pull away a bit from the foam. Be sure the knife 'cut' strokes are toward the foam and to release the knife by sliding it along the edge (releasing it from the fresh wedge of glass). This will help keep the glass in place. I, along with everyone else had this problem. My solution for bulkheads and other 'bench' layups is to rough cut the foam pieces a bit oversize, then after cure, tape my traced drawings to the piece with 3m double sided plastic tape (window treatment section of hardware store) and cut them on band saw about 1/16" or so outside the lines and finished quickly by edge sanding with a hard block. For layups not on the bench or for foam pieces which are already cut to exact size, I knife trim to about 1/6" or so from the foam, then let it finish curing, followed by edge sanding with hard block. Maybe a bit more trouble, but I don't have issues with lifting glass any more and edges are perfect. Food for thought; hope this helps. Larry Schuler Date: Fri, 21 May 1999 11:56:13 -0400 From: Paul Krasa Subject: COZY: Re: [c-a] Thoughts on peel ply This is true, but I believe that this was only an opinion. I did conducted peel testing on three types of samples and could not find any statistically difference between the three sample sets. The samples were four layers of bid made out of Safe-T-Poxy. One sample set had nothing on top of it. The second sample set had peel ply on top of it and the third set was "dusted" with micro. Each sample set was subjected to the ASTM peel test using a Instron Load Frame. All data plotted within the same scatter region. Each builder should conduct testing to ensure the strength of the materials process used. If you can't trust your materials process then don't build an aircraft. This is even more important when it comes ot epoxy/resin systems. If you are not using a well proven epoxy/resin system, then do a stengths of materials testing to ensure the your materials process is sound. One of the only reasons I stick with EZ-Poxy is, it is a well proven in the homebuilding arena, and I have done testing on my materials process to ensure it meets my needs. Airplanes can kill you, and I want to hedge my bets in every way I can. (Climbs off soap box :') ) Paul Long EZ 214LP p.s. .....and I hope my Long EZ is as pretty as Ken's someday. At 09:39 5/21/99 -0400, Ken Miller wrote: >Message text written by Paul Krasa >> >This is the system that I used. I call it "dusting" For example, when the >last layup of the wing is complete sift a layer of micro over the top >surface. The micro will fill in the weave, and reduces the sanding time. >< > > Rutan was asked about this method at a forum and his concern was >that the micro would comprimise the strength of the epoxy in and around the >top ply and recommended it not be done. > >Fly High, Fast and Often, >Ken Miller > >Long-EZ N83LE, multiple trophy winner >Long-EZ/XP N6KD, 1995 Wright Bros. Award Recipient >A&P Technician, EAA Flight and Tech Advisor > > "The Sun always shines on the wreckage" > > From: "Chris Byrne" Subject: COZY: Flox Application Date: Wed, 9 Jun 1999 13:17:39 +1000 Builders This may be known by many of you but I have not seen it in the archives. Take the largest syringe that you can get hold of (mine was 25ml) and enlarge the end to around a 3/16th hole. Works great for laying down flox fillets, is reusable, and not as messy as the piping bag. Last night it turned 25mins work into 5. $US 0 .65 from your Chemist/Pharmacy. And thank you to all who responded to my cowling question. Chris Byrne Sydney From: "Nat Puffer" Subject: Re: COZY: 45 degrees... Date: Fri, 3 Sep 1999 18:02:19 -0500 Builders, If you view the BID cloth, it is very easy to see what the 45 deg. cut line should be. There is no need the mark 45 degrees on your cut table. Regards, Nat ---------- > From: Michael Antares > To: cozy_builders@canard.com > Subject: COZY: 45 degrees... > Date: Friday, September 03, 1999 7:19 PM > > Probably many of you have already thought of this but for those who haven't > (and I managed to go years without thinking of it!), here's a neat way to > easily get a 45 degree angle when you cut glass. Make a straight edge > approximately 53.75 inches long. When you lay it across the standard 38" > wide BID or UNI glass so that the ends of the straightedge touch the sides > of the glass it will be on a 45 degree angle! As I'm sure you're aware the > reason dates back to the Greek era--square root of the sum of the squares. > > > Cozy#413 > Finished through chap 14 except chap 13. > Chaps 16 & 24 mostly finished. Chapters 20 > and 21 finished. Chap 13 in progress, almost > finished. > From: cdenk@ix.netcom.com Date: Fri, 3 Sep 1999 20:00:38 -0500 (CDT) Subject: Re: COZY: 45 degrees... Simply amazing, COOL. I had a piece of masking tape at 45 degrees on my ping pong table cutting surface. Used 2 spring clamps to hold one edge at the table, then grabbed glass perpendicular to the one clamp, pulled straight, and with free hand stretched glass for straight fibers befor cutting. For those just getting started, save all but the smallest (less than 6" minimum dimension) for those little pieces and corners. I think maybe I like the diagonal length straightedge. Roller (Pizza) cutter works great for cutting. From: "John Slade" Subject: Re: COZY: Chap 3 - selvage Date: Sun, 26 Sep 1999 23:42:17 -0400 Dewayne, No doubt more experienced builders will jump on me if I'm wrong, but here's my attempt at clarification: >Does this mean when joining pieces, butted together, or ALWAYS remove the selvage. Re BID: Always remove the selvage when using two pieces of BID (and [almost] always overlap). If the selvage is off the end of the layup and will be scissor trimmed anyway, then there's not much point in removing it early. Re UND: Never remove the selvage [if there is one] and always butt, not overlap. Does that help clear things up? John Slade Cozy #757 (Chap 19) http://kgarden.com/cozy Date: Mon, 27 Sep 1999 07:55:53 +0200 From: "Rego Burger" Subject: COZY: Chap 3 - selvage The selvage on bid is usually much thicker and forms a ridge that needs to be sanded away, it is often not made of glass but some other material of no significant value to the strength of the layup. It's primary job is to keep the cloth from unravelling while you work with it. On uni cloths the selvage is much thinner and less of a problem. Régo Burger RSA From: RWhitt1245@aol.com Date: Mon, 27 Sep 1999 06:48:10 EDT Subject: COZY: selvage Why DO we remove the selvage ? Seems like all it acomplishes is to leave an unraveling mess. Ron Date: Mon, 27 Sep 1999 16:33:59 -0400 From: Jeff Russell Subject: Re: COZY: selvage RWhitt1245@aol.com wrote: > > Why DO we remove the selvage ? Seems like all it acomplishes is to leave an > unraveling mess. Ron, BID and UNI have selvage that might give a bubble problem depending on when it was made from Hexcel. The new rolls that we have been getting do not have a selvage edge on the BID but have been stitched with the fill cut off at the edges. Selvage will be woven and not stitched. This new style from Hexcel does not cause us bubbles and we do not cut it off as before. The UNI has a much finer fill and the bubble problem is much less even if you overlap like BID. BID is almost always used after it is (cut and laid at a 45 degree) an should not unravel as much if it were cut and used on 0 and 90 degrees. Try some samples pieces and see what problems you find. If you have the new stuff? You are one step better than what we had to deal with in the past. Hope that helps -- Jeff Russell/AeroCad Inc. E-mail: Jeff@aerocad.com 2954 Curtis King Blvd. Ft. Pierce, FL. 34946 Shop# 561-460-8020 7:00am to 3:30pm Home# 561-344-6200 Website: http://www.Aerocad.com Composite workshop info: http://www.Sportair.com From: "John Slade" Subject: COZY: Peel ply with plastic? Date: Tue, 28 Sep 1999 13:05:40 -0400 I met a builder recently who had a perfect "mold like" finish on his entire project. He told me that he uses 6mm plastic to squeege out excess epoxy and give him a totally smooth "ready for primer" finish. It seems to me that this technique could save months of filling & sanding while also reducing weight. Any reason why this is a bad idea? John Slade jslade@kgarden.com/cozy From: Epplin John A Subject: RE: COZY: Peel ply with plastic? Date: Tue, 28 Sep 1999 12:39:51 -0500 I used peel ply, cheap polyester stuff from the fabric store, over everything. It looks great, does in fact remove a bit of epoxy from the lay-up. I weighed the material before applying and any epoxy needed to wet it out, then weighed what I removed after cure. Always removed more than applied. The finish looks great, ready for primer or a subsequent bonding operation. Now that I am into the finishing stage I find that this does not do as much as one would think. It does make it easier to apply the Super Fill but you still need to use it everywhere. There are too many misfits to cover, seams etc. The cowling flanges are good size bumps, the wing to spar fit etc. I don't know if you will save any weight by a super smooth finish in itself, probably more can be saved by good fits everywhere. Another place that could be improved on is the winglet attachment. It takes a bit of fill to get this all faired in. One place that peel ply is really good, IMHO, is interior areas. Here this can be painted directly with no fill and look much better than rough fiberglass weave. All in all, I would use the peel ply again, just make better fits where large parts joined. This would call for some additional undercuts that are not specified in the plans. I did not have the experience to foresee most of this in the building stage, my first project. John Epplin Mk4 #467 > -----Original Message----- > From: John Slade [SMTP:rjslade@bellsouth.net] > Sent: Tuesday, September 28, 1999 12:06 PM > To: Cozy builders > Subject: COZY: Peel ply with plastic? > > I met a builder recently who had a perfect "mold like" finish on his > entire > project. He told me that he uses 6mm plastic to squeege out excess epoxy > and > give him a totally smooth "ready for primer" finish. It seems to me that > this technique could save months of filling & sanding while also reducing > weight. > > Any reason why this is a bad idea? > John Slade > jslade@kgarden.com/cozy > > From: "John Slade" Subject: Re: COZY: Peel ply with plastic? Date: Tue, 28 Sep 1999 14:13:35 -0400 John, Thanks for your peel ply comments. I've been using wide [wicks] peel ply myself and like the results. But this guy is using plastic, not peel ply. His finish is like glass. On large areas of fuse and canopy I dont think he'll need any filler at all. John Slade Date: Tue, 28 Sep 1999 14:14:47 -0400 From: "David R. Kuechenmeister" Subject: RE: COZY: Peel ply with plastic? Using it on the interior does sound like a good idea. I've also read about using peel-ply over a coat of microballon filler. That is applying the filler, then the large sheets of peel-ply, then squeegeeing (?) out the excess. Supposedly it cuts out quite a bit of sanding to smooth the filler. At 12:39 PM -0500 9/28/99, Epplin John A wrote: >One place that peel ply is really good, IMHO, is interior areas. Here this >can be painted directly with no fill and look much better than rough >fiberglass weave. All in all, I would use the peel ply again, just make >better fits where large parts joined. This would call for some additional >undercuts that are not specified in the plans. I did not have the >experience to foresee most of this in the building stage, my first project. -- David R. Kuechenmeister Aerospace, Transportation and Advanced Systems Laboratory Georgia Tech Research Institute Atlanta,GA 30332-0853 mailto:David.Kuechenmeister@gtri.gatech.edu Voice: (770)528-7738 PGP Public Key at http://pgpkeys.mit.edu:11371 From: jhocut@mindspring.com Date: Tue, 28 Sep 1999 14:55:07 -0400 Subject: Re: Re: COZY: Peel ply with plastic? > But this guy is using plastic, not peel ply. >His finish is like glass. On large areas of fuse and canopy I dont >think he'll need any filler at all. Using plastic as "peel ply" will not work for the following reasons: 1. To get ANYTHING to adhere to epoxy/fiberglass you need surface roughness at the "microscopic" level. Thus, to get good adhesion with paint you'll have to sand every square inch with fine sandpaper. You'll be sanding pure epoxy, which is way more difficult than sanding micro. 2. No matter what you do, there's going to be a small amount of waviness on any large surface (even if it's not noticeable after removing the plastic it will certainly show up after paining). You'll have to fix this with micro in the low areas, again you'll have to sand to get the micro to adhere. It's much easier to peel ply the entire surface, you'll be ready to apply micro as soon as the peel ply is removed. Jim (building the wings) Hocut From: MARC_ZEITLIN@HP-Andover-om1.om.hp.com Date: Tue, 28 Sep 1999 15:26:50 -0400 Subject: COZY: Peel ply with plastic? John Slade wrote: > Thanks for your peel ply comments. I've been using wide > [wicks] peel ply myself and like the results. But this guy is using plastic, > not peel ply. His finish is like glass. On large areas of fuse and canopy I > dont think he'll need any filler at all. There are two issues here. First, is the surface finish. This is the "smoothness" of the surface. A glass smooth surface is not necessarily what you're looking for, since you'll have to sand it anyway to get to the point that the primer will stick. Second, the surface profile. Using a 4-mil poly sheeting to get a smooth surface implies nothing about the SHAPE of the surface. You can have a glass smooth surface that isn't the right SHAPE, in which case you're going to have to add filler anyway, and you'll have to do a lot of extra sanding to get the filler to stick prior to application. Unless you have a perfect surface profile during layup (which, to tell you the truth, I've NEVER seen happen in moldless construction - there's always SOME filler necessary) a smooth surface is worse than a peel-ply or bare cure surface. It'll just add more work. -- Marc J. Zeitlin email: marcz@ultranet.com Date: Tue, 28 Sep 1999 12:52:50 -0700 From: Eric Westland Subject: Re: COZY: Peel ply with plastic? There is at least one more issue here. When you do this, you are filling the weave with pure epoxy which is more expensive and heavier than the light weight filler you will use later. Date: Tue, 28 Sep 1999 17:21:22 -0400 From: Jeff Russell Subject: Re: COZY: Peel ply with plastic? jhocut@mindspring.com wrote: > Using plastic as "peel ply" will not work for the following reasons: > > 1. To get ANYTHING to adhere to epoxy> snip > 2. there's going to be a small amount of waviness I have found this to be true because of the same as Jim has spoken about. It is also heavier :-) -- Jeff Russell/AeroCad Inc. Date: Tue, 28 Sep 1999 14:17:45 -0700 (PDT) From: Kevin Walsh Subject: Re: COZY: Peel ply with plastic? > There is at least one more issue here. When you do > this, you are > filling the weave with pure epoxy which is more > expensive and heavier > than the light weight filler you will use later. > So, to cap this off, lets try to capture the idea: 1) If you just fill with epoxy and use plastic as a peel ply, you get the wrong shape (probably) and heavier than fill. 2) If you fill with normal fill and use plastic as a peel ply, you get a smooth surface you will just have to sand later to get the correct shape. So, this idea (epoxy/plastic peel ply) seems to be net gain zero. Do people find that "dusting" with fill on the last layup, and then peel ply over the dusting works well? I would assume that you must still do the fill/sand/repeat routine, but that you would have a big head start in filling the weave? Comments? ===== Kevin Russert Walsh Process & Equipment Development Engineer Inhale Therapeutic Systems, Inc. (NASD:INHL)www.inhale.com __________________________________________________ Do You Yahoo!? Bid and sell for free at http://auctions.yahoo.com From: Militch@aol.com Date: Tue, 28 Sep 1999 16:15:54 EDT Subject: Re: COZY: 1 newbie question In a message dated 9/27/99 1:08:42 AM, dmorgan@mis.net wrote: >chapter 3 page 3 it says the selvage is always removed. Does this mean when >joining pieces, butted together, or ALWAYS remove the selvage. > I have always assumed this was a left over from the way they built cloth in the good old days since my cloth as procured from Wicks doesn't have anything special done to the edges. I interpret selvage to mean some kind of finished seam that presumably would add an undesirable bump if left in. The cloth I have has an edge that is best described as a 1/8" fringe. So, to answer your question - I don't do anything with the edge. Given the way the stuff likes to fray, I doubt I could make it any neater if I trimmed the edge off myself. Peter Militch Cozy Mk IV #740 Chapter 7 Date: Wed, 29 Sep 1999 08:25 -0500 (CDT) From: Michael Pollock Subject: Re: COZY: 1 newbie question Peter Militch wrote: >I interpret selvage to mean some kind of finished >seam that presumably would add an undesirable bump if left in. The cloth I >have has an edge that is best described as a 1/8" fringe. Peter, It sounds like you have no selvage on your bid. I have been getting bid from Wicks lately and it also has no selvage. It has already been removed by someone. However, I have received many rolls from Wicks that does have the selvage. Michael.Pollock@wcom.com Flying Velocity N173DT Building Cozy MKIV #643 Date: Tue, 28 Sep 1999 22:54:39 -0500 From: Bulent Aliev Subject: Re: COZY: Peel ply with plastic? jhocut@mindspring.com wrote: > > But this guy is using plastic, not peel ply. > >His finish is like glass. On large areas of fuse and canopy I dont >think he'll need any filler at all. > > Using plastic as "peel ply" will not work for the following reasons: > > 1. To get ANYTHING to adhere to epoxy/fiberglass you need surface roughness at the "microscopic" level. Thus, to get good adhesion with paint you'll have to sand every square inch with fine sandpaper. You'll be sanding pure epoxy, which is way more difficult than sanding micro. There is a trick to that too: we use small sand blaster with silica. It's like spray painting. Fast, you don't miss corners and creates the perfect surface for the final finish. > 2. No matter what you do, there's going to be a small amount of waviness on any large surface (even if it's not noticeable after removing the plastic it will certainly show up after paining). You'll have to fix this with micro in the low areas, again you'll have to sand to get the micro to adhere. It's much easier to peel ply the entire surface, you'll be ready to apply micro as soon as the peel ply is removed. On the contrary: When you remove the plastic the piece looks shiny and you can see how good you are and makes me feel fuzzy inside :) With these lay-ups we removed almost 100% of the air and all the epoxy that can be squeezed out. It's better that vacuum bagging. John Slade is a wetness of the quality and appearance of the lay-ups. > > > Jim (building the wings) Hocut Date: Tue, 28 Sep 1999 22:45:02 -0500 From: Bulent Aliev Subject: Re: COZY: Peel ply with plastic? Kevin Walsh wrote: > > There is at least one more issue here. When you do > > this, you are > > filling the weave with pure epoxy which is more > > expensive and heavier > > than the light weight filler you will use later. I strongly disagree. The whole principle of building sloppy shapes with foam and than filling with micro does not sound right. From the start I changed the bulding methods and before glassing I had a close to perfect shaped fuselage build only with foam and the necessary longerons. The whole thing included the nose and NACA scoop. When I glassed it it was finished. No shaping, no joints no filling sanding, no Micro and there is no joint at the nose. Fibers run continually. Few builders have seen my fuselage and everyone liked it. > So, to cap this off, lets try to capture the idea: > > 1) If you just fill with epoxy and use plastic as a > peel ply, you get the wrong shape (probably) and > heavier than fill. Nonsense! How do you get the wrong shape if your core or whatever you are glassing is correct? > 2) If you fill with normal fill and use plastic as a > peel ply, you get a smooth surface you will just have > to sand later to get the correct shape. If you use peel ply, you still have to sand again all the surfaces before a lay-up. And again: you glass after the correct shape is achieved. > So, this idea (epoxy/plastic peel ply) seems to be net > gain zero. Do people find that "dusting" with fill on > the last layup, and then peel ply over the dusting > works well? I would assume that you must still do the > fill/sand/repeat routine, but that you would have a > big head start in filling the weave? > > Comments? I am afraid you are mixing the procedures big time. It's too late to go in to it tonight. Good Night Bulent > > > ===== > Kevin Russert Walsh > Process & Equipment Development Engineer > Inhale Therapeutic Systems, Inc. (NASD:INHL)www.inhale.com > __________________________________________________ > Do You Yahoo!? > Bid and sell for free at http://auctions.yahoo.com From: MARC_ZEITLIN@HP-Andover-om1.om.hp.com Date: Wed, 29 Sep 1999 08:12:41 -0400 Subject: COZY: Peel ply with plastic? Bulent Aliev wrote: > I strongly disagree. The whole principle of building sloppy > shapes with foam and than filling with micro does not sound right...... I have had a similar experience with my fuselage, and expect to do little if any filling on it. I certainly tried exceptionally hard to hot-wire my cores to the right shape, and also hard-shelled (let's not get into THAT again) to get the shape as close as possible prior to glassing. However, no matter HOW HARD I WORK, there will still be sections of the wings (and a couple of small sections on the fuselage) that will need some filling to obtain the correct shape. Maybe you're better at shaping than I am - that's a distinct possibility - but I can say pretty categorically that my glass work is better than average (and I've been told so by Technical Counselors and other visitors with glassing experience) so if you're in the top 5%, then 95% of the builders are still going to need to do some filling, in which case your technique may not be the best for them. > Nonsense! How do you get the wrong shape if your core or whatever you > are glassing is correct? Well, without a mold, the shape is NEVER perfect. I have a goal to never have more than one millimeter of fill on more than 10% of the surface area, and only weave fill on the other 90% of the surface area. That's substantially better than a lot of builders - I've seen surfaces that needed 1 - 3 mm of fill on practically the whole thing. Even when you THINK the core/base is correct, you sometimes get minor ripples or bumps in the lay-up that require fill later, or you actually have deviations in the core that you can't correct or miss. > If you use peel ply, you still have to sand again all the surfaces > before a lay-up. And again: you glass after the correct shape is > achieved. If you can achieve the "correct" shape consistently, and really need no filling afterwards, then you're a better and more careful builder than the vast majority of us, and I commend you for it. I wish I could do it. -- Marc J. Zeitlin marcz@ultranet.com http://cozy.canard.com Non Impediti Ratione Cognitanis (C&C) Date: Wed, 29 Sep 1999 09:09:38 -0500 From: David Domeier Subject: Re: COZY: Peel ply with plastic? Marc, re "If you can achieve the "correct" shape consistently, and really need no filling afterwards, then you're a better and more careful builder than the vast majority of us, and I commend you for it. I wish I could do it." So do I. If there is one bit of advice to new builders worth mentioning, it is spend a little time preparing a foam surface before glassing - it is easier than filling and sanding later. If I were building again, I would check the quality of pre cut foam cores and opt to have it done if they are good. Hot wire cutting is an art and if your not an artist, they won't be very perfect the first time. I cut several sections twice at added cost and time. The wire tension, temperature, and pull time has to be just right to get it right, and how many of us have had to use a buddy on the other end who knows nothing of the process? But this all can be taken to an extreme whereby you will be spending 18 months just shaping the foam of the fuselage. I know of one guy who did just that while I build the fuselage, wings, and canard. As far as I know that airplane is still in someone's garage and it was 7 years ago. There is a happy balance in all this and that balance resides within each of us. None of our airplanes will be perfect, but some will be a bit more perfect than others. In the end, if the wing to canard tolerance is within .54" and the cg is right, they will fly very nicely no matter how much fill it took to get it reasonable smooth. But I will say this, it is easier by far to get the foam right before glassing than spending 2 years filling and sanding later. dd From: "Brian & Susan DeFord" Subject: Re: COZY: Peel ply with plastic? Date: Wed, 29 Sep 1999 09:12:16 -0700 Was said: > "If you can achieve the "correct" shape consistently, and really need no filling > afterwards, then you're a better and more careful builder than the vast > majority of us, and I commend you for it. I wish I could do it." Well, having spent the last two months doing pretty much nothing but sanding and filling while I wait for my engine to arrive, I can give some first hand experience. I tried my best to keep the surfaces smooth and true to shape when I glassed them, but when I started to do the contouring I found that I didn't do a perfect job. Since this is my first project I have learned a lot about what I would do differently the next time, but have to live with what I did THIS time. So, there is filler in areas such as the spar-to-strake transition, wing spar-to-core areas, winglet attach areas, and areas in the canopy-to-fuselage transition. The whole exterior surface has had the weave filled as suggested by the folks as Poly Fiber (I'm using their SuperFill). Now, I am not admitting I did sloppy work - this is the result of following the plans and ending up with slight depressions and irregularities and such. I've got the good fortune of having Nat live only 15 miles away from me and he has been my EAA Tech Counselor. On each of his visits to my project he has commented that I am doing a good work (well, except for some epoxy runs on a lower winglet - he scolded me for that!) and has sent a couple of prospective or new builders to me so they can see a work in progress. One more note - the Poly Fiber folks also told me that the average amount of filler material applied to a project the size of a Cozy is approximately (2) 3gal kits. Some have used as little as 1 kit and others have used 3 or more. I used (2) 3gal kits plus 2 small "trial" size kits so I used a little more than average. I also had a learning curve where I put on WAY TOO MUCH at the beginning only to sand it all off later. Now that I have the hang of it I am sure I could have done it with 2 kits. Regards, Brian DeFord Date: Wed, 29 Sep 1999 05:57:52 -0400 From: Jeff Russell Subject: Re: COZY: Dusting micro Kevin Walsh wrote: > So, this idea (epoxy/plastic peel ply) seems to be net > gain zero. Do people find that "dusting" with fill on > the last layup, and then peel ply over the dusting > works well? I would assume that you must still do the > fill/sand/repeat routine, but that you would have a > big head start in filling the weave? 1)Dusting can cover up what you need clean for the next layup. 2)It does not fill all the weave of the cloth. 3)It could pull to much extra resin out of the layup. 4)It could save a little time on sanding prep but you still must sand. 5)I do this after spreading Cab-O-sil & resin over a part to remove pin holes to make the resin a little easier to sand. -- Jeff Date: Wed, 29 Sep 1999 11:46:15 -0500 From: Bulent Aliev Subject: Re: COZY:foam cores > > > If I were building again, I would check the quality of pre cut foam > cores and opt to have it done if they are good. Hot wire cutting is an > art and if your not an artist, they won't be very perfect the first > time. I cut several sections twice at added cost and time. The wire > tension, temperature, and pull time has to be just right to get it > right, and how many of us have had to use a buddy on the other end who > knows nothing of the process? That's my point exactly. I did see few wing cores and did not like the final result. I knew that with little experience your (my) chances are good to screw up. So I gave myself one extra step after the hot wire act. I made 1/8" oversize templates for the hot wiring and aluminum final templates. Now I had a peace of mind while cutting and didn't wary about burn in, wire lag, etc. Than I screwed in the final templates and sanded them to final shape. They come so perfect, I was kissing my own hands :). Even Nat published one photo of a core in his news letter. > But this all can be taken to an extreme whereby you will be spending > 18 months just shaping the foam of the fuselage. I know of one guy who > did just that while I build the fuselage, wings, and canard. As far as > I know that airplane is still in someone's garage and it was 7 years > ago. Different strokes.... Many times you spend a little time on the front end to save lots on the end? > There is a happy balance in all this and that balance resides within > each of us. None of our airplanes will be perfect, but some will be a > bit more perfect than others. In the end, if the wing to canard > tolerance is within .54" and the cg is right, they will fly very nicely > no matter how much fill it took to get it reasonable smooth. > > But I will say this, it is easier by far to get the foam right > before glassing than spending 2 years filling and sanding later. > > dd Amen to that. Bulent From: cdenk@ix.netcom.com Date: Wed, 29 Sep 1999 16:24:56 -0500 (CDT) Subject: Re: COZY:foam cores With only a brief instruction, my wife, good cook and housekeeper, but mechanical, not so, we cut the canard cores with no problems. Date: Wed, 29 Sep 1999 08:46:01 +0200 From: Jannie Versfeld Subject: Re: COZY: Peel ply with plastic? Eric Westland wrote: > > There is at least one more issue here. When you do this, you are > filling the weave with pure epoxy which is more expensive and heavier > than the light weight filler you will use later. This is about the most significant issue why I will stick to the plans method of finishing. If one uses thick plastic for a smooth finish .... especially on the fuselage ... what about the wrinkles fromed around the compound curves? Seems it will create alot more difficult sanding as opposed to sanding micro which is a breeze. Conclusion ... every time we change from the plan and try something else ... it adds to building time. kind regrads, Jannie #673 Status ... on landing gear main spar complete canard complete arm rests complete nose complete turtle deck complete canopy complete wing shear webs complete ... waiting inspection winglet cores cut engine ready to install (O-540-E4B5) "0"-Time From: "Larry & Jenny Schuler" Subject: Re: COZY: Peel ply with plastic? Date: Sat, 2 Oct 1999 09:46:30 -0500 >I met a builder recently who had a perfect "mold like" finish on his entire >project. He told me that he uses 6mm plastic to squeege out excess epoxy and >give him a totally smooth "ready for primer" finish. It seems to me that >this technique could save months of filling & sanding while also reducing >weight. > >Any reason why this is a bad idea? Yup, been there, done that. It's easy to remove too much epoxy without the ability to correct it before cure. I found, for me, that peel ply alone is best for doing same thing. Allows addition of epoxy if I squeeze out too much; and, leaves the surface mostly ready for finish. The shiny surface left by plastic still needs sanding..... Poor man's vac bag is made from peel ply then layer of plastic. Works real well. Larry Schuler MK-IV plans #500 From: Muzzy Norman E Subject: RE: COZY: Peel ply with plastic? Date: Mon, 4 Oct 1999 13:46:24 -0500 <> At the composite workshop at Oshkosh, one of the instructors relayed that they received Aercoupes that were built in England that had beautiful finishes. After several days in the hot Florida sun, they began to see the weave of the fabric. Apparently, they material did not postcure in England due to the cooler building temperatures and/or lack of sun? If this is true, then the 'perfect' surface that appears on a surface the day after you lay it up may still need filling and finishing down the road. It looks like there may be cosmetic advantage to some degree of postcuring before finishing (in addition to the mechanical strength characteristics. Regards- Norm Muzzy <> Flying is more fun than sex, and not nearly as messy. From: SWrightFLY@aol.com Date: Mon, 4 Oct 1999 17:53:11 EDT Subject: Re: COZY: Peel ply with plastic? In a message dated 10/4/99 2:05:13 PM Central Daylight Time, MuzzyNormanE@Waterloo.deere.com writes: << After several days in the hot Florida sun, they began to see the weave of the fabric. Apparently, they material did not postcure in England due to the cooler building temperatures and/or lack of sun? >> I believe this is due to the paint and primer shrinking with heat and time and thus you can see the weave. Steve Wright Aircraft Works LLC: Electric Nose-Lift for EZEs Date: Tue, 12 Oct 1999 05:48:14 -0400 From: Jeff Russell Subject: COZY: Re: Video David de Sosa wrote: > > The only problem I have found with pouring epoxy onto cloth is that if > you wait too long, it soaks up quickly into the area it was poured on. > When squeeging it out, the original area that it was poured on always > appears a little darker at first which leads me to believe that this > area may end up with a slightly higher concentration of epoxy when all > is said and done even after squeeging it out well for several minutes. > Granted it doesn't appear to be noticeable after squeeging, but I wonder > if it really does get completely dispersed in the process. Use a hair dryer when squeeging. It thins the resins so you can remove as much of the resin that you want. The quicker you get wet out, the faster you can remove any excess in the part and the lighter the part will be because the resin will stay thin. -- Jeff Russell/AeroCad Inc. From: "Larry & Jenny Schuler" Subject: Re: COZY: SportAir Video on Composite Date: Sat, 9 Oct 1999 11:10:03 -0500 > He was pouring the expoxy straight from the cup into the clothes like >if he was adding mapple sirup to grandma`s apple cake then he was scrubbing >with he squegges a lot of expoxy back to the pot. > Noticed your comment about your own brushing/stabbing. That takes a lot of time. On big layups the epoxy could begin to cure before you get done! I believe the method demonstrated is quite useful in saving a LOT of time and is recommended by Nat. The demonstrator may have gotten carried away by pouring too much on the part initially. After doing this method a few times, I got the hang of guesstimating the right amount to pour out based on the area to be covered; pouring a bit more where needed or finishing a small lean area with a brush. Any small excess can easily be scraped (or picked up by the squeegee) back into the cup for use elsewhere. Works extremely well on larger areas, but just as valid on corner tapes (in smaller quantities of course). I started just like you, using only a brush and stippling. I only do that now in very small or out of the way areas. Larry From: "John Slade" Subject: Re: COZY: SportAir Video on Composite Date: Sat, 9 Oct 1999 13:46:26 -0400 Denis, > He was pouring the expoxy straight from the cup into the clothes like >if he was adding mapple sirup to grandma`s apple cake then he was scrubbing >with he squegges a lot of expoxy back to the pot. > >Noticed your comment about your own brushing/stabbing. That takes a lot of >time. On big layups the epoxy could begin to cure before you get done! I think that the best method for putting the epoxy on depends on the viscosity / type of the resin used. Warm MGS is like water. Much less viscous than the stuff used by Rutan in the video. I find that the easiest and fastest method is to paint it on with a brush. Most of the glass wets up after one pass. my 2c, John Slade Cozy MKIV #757 http://kgarden.com/cozy From: "Denis Thomassin" Subject: RE: COZY: SportAir Video on Composite Date: Sun, 10 Oct 1999 10:33:43 -0400 Yesterday for the first time I used the squeegee to layup the clothes on a the center front seat back brace a triangular piece. It when very well and this morning I checked the cure result I a was very happy about it. ! After all I learned at less one thing from the video that worth the price ;) Denis Thomassin 705, Montreal Date: Mon, 11 Oct 1999 18:07:41 -0500 From: David de Sosa Subject: Re: COZY: SportAir Video on Composite The only problem I have found with pouring epoxy onto cloth is that if you wait too long, it soaks up quickly into the area it was poured on. When squeeging it out, the original area that it was poured on always appears a little darker at first which leads me to believe that this area may end up with a slightly higher concentration of epoxy when all is said and done even after squeeging it out well for several minutes. Granted it doesn't appear to be noticeable after squeeging, but I wonder if it really does get completely dispersed in the process. David de Sosa Cozy MkIV #080 Larry & Jenny Schuler wrote: > > > He was pouring the expoxy straight from the cup into the clothes like > >if he was adding mapple sirup to grandma`s apple cake then he was scrubbing > >with he squegges a lot of expoxy back to the pot. > > > From: "Nat Puffer" Subject: COZY: stippling Date: Mon, 11 Oct 1999 14:43:48 -0500 Builders, I meant to copy all the builders on this, but I guess I didn't hit the right button. In the early Varieze days, a Ph.D consultant (I really don't have anything against Ph.Ds, and don't mean to offend any of you who are) bought Varieze plans and got the bright idea to have a highschool build it for him. He instructed the students to "stipple" the layup with brushes to wet out the cloth. In the Varieze, the first chapter was to build the canard. Well, Burt Rutan came to town for a workshop and invited the Varieze builders to bring samples of their work. This guy brought his canard. I never saw anything that looked so horrible. It looked as though it had been through a hail storm. There were deep dimples all over it. The students had used brushes after the epoxy had cured the bristles. It was like pounding with a hammer. When Burt saw this, he almost had a heart attack, and on the way to the airport the next day, he said he couldn't sleep all night. So much for "stippling". Nat From: "Nat Puffer" Subject: Re: COZY: Epoxy ratio to glass of MSG Date: Thu, 14 Oct 1999 11:06:34 -0500 Larry, It is not practical for a homebuilder to weigh out the glass and then weigh out the epoxy as a function of the glass. Maybe in a factory they can do this. The only way we know of for a builder to use the correct amount of epoxy is to make the weight sample instructed in the Educational Chapter, and if it comes within the tolerance allowed, then use it during the course of construction to make sure you are using the correct amount of epoxy. It you use too much epoxy, you will have a heavy airplane. If you don't use enough, you will have a weak airplane. The way you judge is by looking at your educational sample. Regards, Nat From: "Capps Family" Subject: COZY: Epoxy ratio to glass of MSG Date: Thu, 14 Oct 1999 12:18:44 -0500 I'm curious, since MSG wets out so much easier, what mixing ratio of epoxy to glass do you start out with (i.e. 1 to 1 by weight of glass)? And what do you feel your finished parts epoxy to glass ratio is (40% epoxy to glass)? Blue Skies; Larry A. Capps #829 Naperville, ILFrom ???@??? Fri Oct 15 06:01:17 1999 Return-Path: owner-cozy_builders@betaweb.com Received: from twc2.betaweb.com (majordomo@betaweb.com [206.43.209.18]) by acestes-fe0.ultra.net (8.8.8/ult/n20340/mtc.v2) with ESMTP id RAA26484 for ; Thu, 14 Oct 1999 17:16:16 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id QAA16944 for cozy_builders-list; Thu, 14 Oct 1999 16:11:49 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from mail0.mia.bellsouth.net (mail0.mia.bellsouth.net [205.152.16.12]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id QAA16939 for ; Thu, 14 Oct 1999 16:11:40 -0400 Received: from amd300 (host-209-215-55-145.pbi.bellsouth.net [209.215.55.145]) by mail0.mia.bellsouth.net (3.3.4alt/0.75.2) with SMTP id QAA12187 for ; Thu, 14 Oct 1999 16:09:54 -0400 (EDT) Message-ID: <006301bf167f$605b0a20$806cfea9@amd300> From: "John Slade" ; Thu, 14 Oct 1999 17:16:16 -0400 (EDT) Received: (from majordomo@localhost) by twc2.betaweb.com (8.8.5/8.8.5) id QAA16944 for cozy_builders-list; Thu, 14 Oct 1999 16:11:49 -0400 X-Authentication-Warning: twc2.betaweb.com: majordomo set sender to owner-cozy_builders@betaweb.com using -f Received: from mail0.mia.bellsouth.net (mail0.mia.bellsouth.net [205.152.16.12]) by twc2.betaweb.com (8.8.5/8.8.5) with ESMTP id QAA16939 for ; Thu, 14 Oct 1999 16:11:40 -0400 Received: from amd300 (host-209-215-55-145.pbi.bellsouth.net [209.215.55.145]) by mail0.mia.bellsouth.net (3.3.4alt/0.75.2) with SMTP id QAA12187 for ; Thu, 14 Oct 1999 16:09:54 -0400 (EDT) Message-ID: <006301bf167f$605b0a20$806cfea9@amd300> From: "John Slade" To: "Cozy Builders" Subject: Re: COZY: Epoxy ratio to glass of MSG Date: Thu, 14 Oct 1999 16:04:51 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-cozy_builders@betaweb.com Precedence: bulk Reply-To: "John Slade" X-UIDL: 4a08666eee48db613a727eb4236abe50 Larry, >I'm curious, since MSG wets out so much easier, what mixing ratio of epoxy to >glass do you start out with (i.e. 1 to 1 by weight of glass)? And what do you feel >your finished parts epoxy to glass ratio is (40% epoxy to >glass)? As Nat says, this isnt something we measure. Just follow chap 3 instructions, get the layup fully wet, then squeege out as much epoxy as you can. A good way to see if you have too much epoxy is to stop during a squeege pass and look for a hump where you stopped. I often use wax paper to squeege through [flat surfaces]. This helps get out more of the excess. Some even use a thin plastic film. There is much discussion on various techniques in the archives. A lot depends on the temperature of your parts, the air and the epoxy. Regards, John Slade From: Militch@aol.com Date: Thu, 14 Oct 1999 16:32:17 EDT Subject: Re: COZY: Epoxy ratio to glass of MSG In a message dated 10/14/99 5:23:52 PM, cappsfan@ameritech.net wrote: >I'm curious, since MSG wets out so much easier, what mixing ratio of epoxy to >glass do you start out with (i.e. 1 to 1 by weight of glass)? > >And what do you feel your finished parts epoxy to glass ratio is (40% epoxy to >glass)? > Honestly, I haven't got a clue. I weighed the first few parts I made and they were right in the middle of the weight range quoted by others for the same parts, so I figured I had it about right. I don't doubt that I could safely remove a little more with a substantial increase in squeegee passes, but I worry more about dry-spots than I do about an extra 1% of weight, so I do it the way the instructions tell you to, and always use my trusty hair-dryer, and it all seems ok. I have adopted the philosophy that it will weigh what it weighs, and as long as I don't try anything silly (like 55 degree layups), it will work. Regards, Peter From: alwick@juno.com Date: Thu, 14 Oct 1999 19:18:55 -0700 Subject: Re: COZY: Epoxy ratio to glass of MSG I missed the original post, since I'm done building components tend to blow past stuff that doesn't apply. However, what a creative idea! If you are using a sensitive gram scale for your epoxy measurements, you have an opportunity to eliminate some of the guess work in the building process. Clearly there is an optimum ratio of epoxy to glass. You can determine the ratio by weighing the components on your first layups and averaging the results. You may have to also measure the room temperature and develop a chart. What good will this do? You will probably waste less epoxy than most. You will likely reduce frequency of rich and lean layups. I would expect there are a few layups where it wouldn't be practical, since it would be inconvenient to figure out how much glass you are going to need. It wouldn't take too much testing to determine a precise ratio to strength test. Sure would help new builders to know for sure they have optimized their building process. Much more scientific approach than looking for trapped air. My hat is off to the originator of this idea. -al From: "John Slade" Subject: Re: COZY: Epoxy ratio to glass of MSG Date: Fri, 15 Oct 1999 10:25:50 -0400 Al, >You will probably waste less epoxy than most. Perhaps, I don't think that's important. >Much more scientific approach than looking for trapped air. Trapped air, bubbles and areas of dryness are the main things we want to avoid? These won't affect the weight of epoxy used, especially if the distribution of epoxy is irregular. >My hat is off to the originator of this idea. In this case, I'll keep my hat on. I'd recommend - forget weighing the glass and concentrate on careful visual inspection using a flashlight. Epoxy experts? - Gary? John Slade Cozy MKIV (still) From: "Hunter, Gary GA SCC" Subject: RE: COZY: Epoxy ratio to glass of MSG Date: Fri, 15 Oct 1999 11:12:47 -0500 John Slade wrote: > I'd recommend - forget weighing the glass and concentrate on careful > visual > inspection using a flashlight. > > Epoxy experts? - Gary? > After you have done a few lay-ups using this technique, particularly the larger ones, I believe you will discover that keeping track of the numbers will be more effort that it is worth. IMHO - With the advantageous low viscosity of MGS system, careful and deliberate control of shop temperature and careful refined laminating skills (that comes with experience), you will achieve the same result. In my experience, the most significant contributors to overweight projects is: 1) Deviation from plans. 2) Poor surface contours that wind up requiring a lot of microfill. 3) Overly large flox joints and fillets. 4) Overall sloppy workmanship. Kindest Regards, Gary Hunter Technical Service Representative EPOXY RESINS TECHNICAL INQUIRY SHELL CHEMICALS, USA Toll Free in North America - 800-832-3766 International - 281-544-6600 Facsimile - 281-544-6604 Email - gahunter@shellus.com This communication is pursuant to service agreements as applicable. Date: Fri, 15 Oct 1999 09:21:36 -0700 From: "Bob Earley" Subject: COZY: Epoxy ratio to glass of MSG Hi All, I'm no expert, but this idea doesn't make much sense to me for three reasons... 1) seems it would be incredibly time consuming 2) would require the purchase of a readable scale, in addition to the pump or balance scale that you're using for epoxy mixing 3) if there was a perfect ratio, you would then have to wet out all the cloth evenly, even the excess that you're going to trim off. I usually have a comfortable border to trim off, but I only wet out just beyond the edge of the foam. BTW, I've been using MGS, too. Bob Join 18 million Eudora users by signing up for a free Eudora Web-Mail account at http://www.eudoramail.com From: Militch@aol.com Date: Thu, 14 Oct 1999 11:38:45 EDT Subject: Re: Re: COZY: SportAir Video on Composite In a message dated 10/9/99 5:53:52 PM, rjslade@bellsouth.net wrote: >I think that the best method for putting the epoxy on depends on the >viscosity / type of the resin used. Warm MGS is like water. Much less >viscous than the stuff used by Rutan in the video. I find that the easiest >and fastest method is to paint it on with a brush. Most of the glass wets up >after one pass. > I agree with John. I use MGS and while I often pour and then squeegee, somehow I never get to finish a job without using a brush. It is very easy and quick to move the MGS around with a 2" brush, and you can easily get the stuff where you need it. Also I find that it is very easy to move the cloth or distort it with a squeegee unless a very large area is already wet, so that puts you in a chicken and egg situation. Regards, Peter From: "Denis Thomassin" Subject: COZY: Taping corner chapter six Date: Mon, 15 Nov 1999 10:48:55 -0500 Newbie question :) Once the fuselage and bulkhead are assembled in chapter six we must tape with two layup of BID in all the corner of F22 - Instrument pannel - Back seat - Landing gear bulkhead). Should we first use dry micro and create a filet to radius the corner ? So far they only indication about this is in the reinforcement part of the instrument panel. Thanks ! Denis Thomassin 705 Montreal, Canada speaking of glass over foam (the same size of foam and number of layers of glass on a specific piece) comparisons. One cannot compare the total weight of a Velocity to the Cozy in the number of gallons of epoxy one uses. Measuring apples to apples, I am getting about 10% less weight per size of layup with the Aeropoxy than the Hexel. Also, the Aeropoxy is about 36% cheaper per gallon than the Hexel that I used. Michael.Pollock@wcom.com Flying Velocity N173DT Building Cozy MKIV #643 From: "John Slade" Subject: Re: COZY: Taping corner chapter six Date: Mon, 15 Nov 1999 11:26:40 -0500 Denis, I think you're supposed to use flox to radius corners on these structural joins. John Slade Date: Mon, 15 Nov 1999 11:07:08 -0600 From: "Tom Brusehaver" Subject: Re: COZY: Taping corner chapter six > Once the fuselage and bulkhead are assembled in chapter six we must tape > with two layup of BID in all the corner > of F22 - Instrument pannel - Back seat - Landing gear bulkhead). Should we > first use dry micro and create > a filet to radius the corner ? So far they only indication about this is in > the reinforcement part of the instrument panel. The easiest way to do this, is using the flox as the fillet. While it is still wet, just lay in the tape, and peel ply it. If you haven't learned the trick about wetting out tape on plastic, I'll give it to ya here. Take some heavier plastic, 14mil (I think that is what I use). Have a peice about twice as big as you need. Draw out some rectangles 2in wide (or whatever size tape you need) Then flip the plastic sheet over. Lay the glass on this part of the plastic wet out one ply, then wet out the second ply. Flip the flap of extra plastic over the second glass ply, and squeege the excess epoxy out. Using your scissors, cut the strips on the lines drawn at the beginning. Peel one ply of plastic off, place the tape into the corner. squeege on the plastic, getting out all the bubbles, then peel off the top layer of plastic. No fraying, less waste. Date: Fri, 19 Nov 1999 08:48:10 -0600 From: Michael Pollock Subject: RE: COZY: Epoxy system >From Nat Puffer: >Michael and builders, >It takes less time with no sacrifice to quality to use an excess of epoxy >on all layers except the last. If you try to make each layer perfect, on >the new layer you are working the epoxy down through the air which is >coming up. Much harder. If you use an excess underneath, the new layer is >wet out from underneath and helps to drive the air out ahead of it. This is >an example of when you are too careful, you just make more work for >yourself. Nat, If I am placing several layers down of bid or uni, I usually prewet everything on a piece of plastic and then transfer it. Using plastic on both sides and then using a squeegee to pull the excess resin out before I transfer it to a prewetted surface. However, when I am doing spar cap tape or similar, I try to leave a little wet on the previous layer so I do not have to push so much resin through the cloth. I will try on the other spar cap the method of leaving too much resin on previous layers and then pulling out most of it towards the end. I just do not want to have a heavy plane. Lighter planes fly faster:) Thanks for the suggestion Nat. Michael.Pollock@wcom.com Flying Velocity N173DT Building Cozy MKIV #643 From: "Rick Maddy" Subject: COZY: Clean-up Date: Tue, 30 Nov 1999 22:27:21 -0700 I just finished the first practice layup. I made a lame attempt at cleaning up using soap and water. For future reference - how do I clean the squegee, butyl gloves, and brush? Everything has epoxy and fiberglass strands all over it. Do I used MEK? Alcohol? Vinegar? Soap and water? Chapter 3 only talks about cleaning the brush with soap and water. I don't like the idea of using the bathroom sink for this. I have this fear of fiberglass fibers becoming a bullet proof clog in the drain. Rick Maddy (cozy@maddyhome.com) Cozy Mk IV #0824: Chapter 4 (www.maddyhome.com/cozy) From: "John Slade" Subject: Re: COZY: Clean-up Date: Sun, 28 Nov 1999 09:38:13 -0500 Rick, >For future reference - how do I clean the squegee, butyl gloves, and brush? Everyone seems to have a different method for this. I've tried various recommended approaches over the last 9 months and settled on the following: Gloves. I use disposable nylex medical gloves. (Walgreens $7.50 / 100). On a big layup I often change gloves two or three times. Very handy if you need to "touch something sensative". Brushes I used to throw them out, then someone suggested a large sealed bottle of MEK. After use I drop them in there and reseal. Next time I need a brush the MEK evaporates in seconds and the brush is ready to go. Need to change the MEK every month or so. Squeege I like the 6 inch squeeges rubber from Wicks. I have one cut in half for smaller jobs & spar caps. Cheap ones just dont cut it. Best thing is to clean these with MEK after use, but I often forget. I've discovered that my belt sander cleans them up nicely in a couple of seconds. Regards, John Slade, Cozy MKIV #757, http://kgarden.com/cozy Date: Wed, 01 Dec 1999 05:50:12 -0500 From: Jeff Russell Subject: Re: COZY: Clean-up Rick Maddy wrote: > how do I clean the squegee, butyl gloves, and brush? > Do I used MEK? Alcohol? Vinegar? Soap and water? We use Lacquer thinner in a jar and soak the brushes. Apple cider vinegar will also work very well. -- Jeff Russell/AeroCad Inc. E-mail: Jeff@aerocad.com 2954 Curtis King Blvd. Ft. Pierce, FL. 34946 Shop# 561-460-8020 7:00am to 3:30pm Home# 561-344-6200 Website: http://www.Aerocad.com Composite workshop info: http://www.Sportair.com From: Epplin John A Subject: RE: COZY: Clean-up Date: Wed, 1 Dec 1999 07:29:49 -0600 Rick: Soap and water will work but is a pain. The best soap I found was FAST ORANGE waterless hand cleaner from Permatex, it contains a mild abrasive and works fairly good. I used this method for the first few sessions, like you I was concerned about the plumbing. I have a laundry sink in the basement with a fairly fine strainer that caught a lot of loose fibers. As much as I hate to say it, soap and water is hardly workable. Finally, I went to wallyworld and got a shallow square plastic refrigerator container, about 9 x9 x 2, with a tight fitting lid then to Loews and got a gallon of Acetone. I wash up everything with this, using a brush, and dry with rag. Works excellent. I also use Ply 9 barrier cream, leave this on till after you have everything washed up then the Fast Orange and water on the hands. Use a brush to get the gook out of your nails etc. I am in the finishing stages, have used 4 gal of acetone and had no problem with skin rash or allergy. Just clean up the bowl once in a while and replace the acetone. Be careful with the acetone, it will dissolve many plastic handles. John Epplin Mk4 #467 > -----Original Message----- > From: Rick Maddy [SMTP:cozy@maddyhome.com] > Sent: Tuesday, November 30, 1999 11:27 PM > To: Cozy Builders E-Mail List > Subject: COZY: Clean-up > > I just finished the first practice layup. I made a lame attempt at > cleaning > up using soap and water. For future reference - how do I clean the > squegee, > butyl gloves, and brush? Everything has epoxy and fiberglass strands all > over it. > > Do I used MEK? Alcohol? Vinegar? Soap and water? Chapter 3 only talks > about > cleaning the brush with soap and water. I don't like the idea of using the > bathroom sink for this. I have this fear of fiberglass fibers becoming a > bullet proof clog in the drain. > > Rick Maddy (cozy@maddyhome.com) > Cozy Mk IV #0824: Chapter 4 (www.maddyhome.com/cozy) From: gmellen@us.ibm.com Date: Wed, 1 Dec 1999 09:08:08 -0500 Subject: Re: COZY: Clean-up For future reference - how do I clean the squegee, butyl gloves, and brush? I don't ! Throw away the brushes or if it was a small layup I freeze them in a plastic bag and reuse them. Squegees, I buy cheap ones and wipe them off with a paper towel until they are too bad and then throw them away. I use laytex and cotton liners ( I am not allergic ) and throw them away after every layup. George mellen Date: Wed, 01 Dec 1999 08:52:05 -0600 From: "Daniel D. Pettinger" Subject: Re: COZY: Clean-up Hi Rick, I use MEK. If the epoxy is cured on the squeegee, one of your few options left is to use sand paper. Otherwise take a paper towel wet with MEK and wipe it off. I use a minimum of two paper towels, one after the other so that a clean one is used for the final rub. Three usually works best. I would suggest laying out the dirty squeegee, scissors and anything else sticky and while wearing the gloves, wipe them off, including the gloves. I also think it is a very good idea to wear a respirator designed for absorbing organic vapors while using MEK. MEK is very volatile. A word of caution: Be very careful not to get the MEK especially mixed with epoxy on your skin. This creates a situation were your exposure to epoxy is vastly increased since the MEK/Epoxy solution has a tendency to spread to a wide area of your skin. If you do get Epoxy on your skin DO NOT USE MEK to clean it off. Use lots of soap and water. There is a very simple technique that works great for cleaning the brush. This was posted a few months ago. I didn't believe it would work until I tried it. Take a dry paper towel and roll you brush up in it. Make sure the bristles are in good contact with the towel. Wet the paper towel with MEK. You don't have to soak the paper towel, just get it fairly damp. Place it in a sealed plastic bag. I've found that the Zip Lock Freezer bags work very good. Come back the next day and the brush is as good as new. I've found that the brush can be used much more than four times using this technique. Dan Pettinger Cozy Mk IV #722 Last of chapter 6. Rick Maddy wrote: > I just finished the first practice layup. I made a lame attempt at cleaning > up using soap and water. For future reference - how do I clean the squegee, > butyl gloves, and brush? Everything has epoxy and fiberglass strands all > over it. > > Do I used MEK? Alcohol? Vinegar? Soap and water? Chapter 3 only talks about > cleaning the brush with soap and water. I don't like the idea of using the > bathroom sink for this. I have this fear of fiberglass fibers becoming a > bullet proof clog in the drain. > > Rick Maddy (cozy@maddyhome.com) > Cozy Mk IV #0824: Chapter 4 (www.maddyhome.com/cozy) From: alwick@juno.com Date: Wed, 1 Dec 1999 06:52:07 -0800 Subject: Re: COZY: Clean-up I'm all done building my plane, just assembling and installing now. Never had a need to use any cleanup chemicals. Just wipe off brush, wrap in plastic wrap, pop in freezer. Wipe off squeegee. Use disposable cups. Use ply-9 for hands prior to glassing. In my 5 years of building, I went thru around 40 brushes. Not too bad. Makes for a much happier life. -al On Wed, 1 Dec 1999 07:29:49 -0600 Epplin John A writes: > Rick: > > Soap and water will work but is a pain. The best soap I found was > FAST > ORANGE waterless hand cleaner from Permatex, it contains a mild > abrasive and > ___________________________________________________________________ Get the Internet just the way you want it. Free software, free e-mail, and free Internet access for a month! Try Juno Web: http://dl.www.juno.com/dynoget/tagj. From: Militch@aol.com Date: Wed, 1 Dec 1999 20:07:17 EST Subject: Re: COZY: Clean-up In a message dated 12/1/99 12:38:49 AM, cozy@maddyhome.com wrote: >up using soap and water. For future reference - how do I clean the squegee, > >butyl gloves, and brush? Everything has epoxy and fiberglass strands all > I use throw-away vinyl gloves, and throw away the brushes (although sticking them in a sealed jar of MEK is good for a few uses. I use a paper towel and a bit of MEK to clean the squeegee and if that isn't good enough, a quick rub against the belt sander once the epoxy cures. Regards Date: Sun, 05 Dec 1999 12:06:34 +0200 From: Jannie Versfeld Subject: COZY: Spar Caps - UNI Tape - Dumb Struck Fellow Canardians, Please help. Whilst I was laying up the canard and later on the right wing spar caps, it seemed as though I would run out of spar cap material (3" NUI Tape). I decided to measure out the remaning tape and found I only had 44 yds left to do the remaining left wing top & bottom caps. Calculations show that I need at least 54 yds based on the number of plies and lengths. My calculations show that I would have used a total of 174 yds in all given a little wastage. The plans call for 282 yds which I ordered from Wicks Aircraft Supply. I recieved TWO rolls of UNI Tape and at the time ( about 1&1/2 years ago ) did not measure it out abeing afraid of distorting the fibres further. One of the rolls were re- wound and the fibres was alreday extremely distorted and damaged. the re-wound roll was joined at about 22 places to make up the lengths. It seems as though they may have been out of stock and had to make do with compiling a roll with many cut-offs. I dont belive that Wicks would deliberately have made such an error and I must reiterate that they have always given me a professional and speedy service and I am sure that they will rectify this at their own expense. The short shipping is not the problem I want to address here, I plan on taking it off line with Wicks. It is the issue of where does all the layers go in the plane?? and did I do something wrong?? I used 14 layers in the canard top spar shortening each layer after the second layer by 4" each side and the bottom cap took 11 layers to fill also shortening 4" each side. Total of 62 yds was used in the canard Total of 56 yds was used in the right wing Total of 56 yds was used in the left wing Total required 174 less 20 yds unusable = 154 yds hence the 10 yds short to complete. Why does the plan call for 282 yds?? I dearly hope I did not leave any layers out. Your comments please!! Kind regards, Jannie Versfeld Cozy MKIV #673 Date: Sun, 05 Dec 1999 08:09:39 -0500 From: Jeff Russell Subject: COZY: Re: UNI Tape Jannie Versfeld wrote: > Total of 62 yds was used in the canard > Total of 56 yds was used in the right wing > Total of 56 yds was used in the left wing > > Total required 174 less 20 yds unusable = 154 yds hence the 10 yds short > to complete. > > Why does the plan call for 282 yds?? What happened to the main center section spar? -- Jeff Date: Sun, 05 Dec 1999 17:21:11 +0200 From: Jannie Versfeld Subject: Re: COZY: Re: UNI Tape Snip > > > > Why does the plan call for 282 yds?? > > What happened to the main center section spar? > -- > Jeff omigod I didn't calculate that and it turns out that calculations show that the main spar that I so conveniently forgot I had done that is hidden away in the rafters used a total of 122 yds ... so .... Total of 62 yds was used in the canard Total of 56 yds was used in the right wing Total of 56 yds was used in the left wing Total of 122 yds was used in the main spar So final count is 296 yds and Nat states 282 yds and I am short of 10 yds taking into consideration of the damaged portions which I had to discard. I thinkt the plans should ne changed to 300 yds on UNI Tape to allow for some overlap at the ends. None the less I am still short of 10 yds and Wicks did supply me the correct length. At least I can sleep well without the worry of leaving out some plies. Thanks Jeff ... I was stupid to forget about the main spar. From: N433DP@aol.com Date: Sun, 5 Dec 1999 11:59:29 EST Subject: Re: COZY: Re: UNI Tape I came up 10 yards short also. Thought I may have put more in the Canard (Fill trough until even) Maybe not? Doug From: "Capps Family" Subject: COZY: Spars:UNI usage Date: Sun, 5 Dec 1999 13:35:01 -0600 To All, SPAR-CAP THICKNESS - CENTERSECTION SPAR AND WING The number of plies of the UND tapes for the spar caps shown in the plans (Chapter 14 and 19) is based on each ply being .035 to .038 thick. We have found that some of the UND tape is of less bulk than expected, and is laying up only about .025 per ply. If this happens, the spar is weak and the depressions are not filled flush. Check your spar cap material by making a 5-ply layup. Cure then measure thickness. It should be 0.18 thick. If it is only 0.125 thick you must add the following plies to all your spar cap layups. All the additions can go on top of the plans shown caps. - Burt Rutan Blue Skies, Larry Larry A. Capps #829 Naperville, IL capps@mediaone.net Snip" I think the plans should be changed to 300yds on UNI Tape to allow for some overlap at the ends. None the less I am still short of 10yds and Wicks did supply me the correct length. At least I can sleep well without the worry of leaving out some plies. Thanks Jeff ... I was stupid to forget about the main spar." From: cdenk@ix.netcom.com Date: Sun, 5 Dec 1999 18:37:29 -0500 (EST) Subject: Re: COZY: Spars:UNI usage Was said I always assumed that this material, along with many others, was approved by the designers when furnished by approved suppliers to a specification. Given a specification which includes number of strands, diameter of the strands in the crossection, this should lay up, when squeeged down an area say not greater than +/- 5 percent of specified I would think, not 33% less. Has the specification been changed?? From: "Nat Puffer" Subject: Re: COZY: Spars:UNI usage Date: Sun, 5 Dec 1999 18:20:57 -0600 Dear Carl, I don't know what Uli says in the Cosy (Europe) plans for the Cosy, but we say the suggested number of layers is the theoretical number, but it might require more or less to fill up the spar cap troughs (after removing the cross threads) for the canard, the centersection spar, and the wing. This is in recognition of the fact that thickness is more important than the number of layers of a given product (builders have been known to use glass in other forms). If the spar is premolded by a vendor, there isn't really a spar cap trough to fill up, and if that vendor uses a different material than what we specify in the plans, then we have to run a test to determine how much of the material he uses is required to make the equivalent thickness of spar cap material, and we have done this and our approval is contingent upon his following our specification based on the material he is using. Since the thickness of different products, or different batches of the same product can vary, it is safer just to specify the thickness of the spar cap (or trough that it is laid up in) than to rely only on only the number of layers. I think the first Long EZ built from plans got some spar cap tape that was only 1/2 as thick as it should have been, and the builder filled up the rest of the trough with either micro or flox. Even with only 1/2 of the spar cap thickness that Burt intended, RAF did a stress strain test on the wing and determined that the wing exceeded the design requirements. I hope this answers your concern and any concern you might have caused Cozy builders. Regards, Nat ---------- > From: cdenk@ix.netcom.com > To: capps@mediaone.net; cozy_builders@canard.com > Subject: Re: COZY: Spars:UNI usage > Date: Sunday, December 05, 1999 5:37 PM > > Was said > > I always assumed that this material, along with many others, was approved by the designers when furnished by approved > suppliers to a specification. Given a specification which includes number of strands, diameter of the strands in the > crossection, this should lay up, when squeeged down an area say not greater than +/- 5 percent of specified I would think, not > 33% less. Has the specification been changed?? > From: Militch@aol.com Date: Sun, 5 Dec 1999 22:15:09 EST Subject: Re: Re: COZY: Spars:UNI usage In a message dated 12/5/99 6:47:52 PM, cdenk@ix.netcom.com wrote: >Was said Does it really matter what the bulk is? The plans tell you to fill the trough, so in the end, regardless of the number of fibers packaged in a tape, I would expect that you should get the right amount of glass. Regards, Peter Militch #740 From: cdenk@ix.netcom.com Date: Sun, 5 Dec 1999 22:31:55 -0500 (EST) Subject: Re: COZY: Spars:UNI usage Nat said This is getting interesting, here's what the Classic says: For the centersection spar and wings, one is to lay up 5 plys in a trough, and then measure the thickness. The material comes as 0.025" and 0.35" per ply, and your layup will be either 1/8", or 3/16". The drawings show a specified number and length of plys, if you have the thicker material, certain layers are left out, otherwise use all pieces. For the Roncz canard (the drawings were not part of the original book): Fill the trough level. I just have a hard time believing that a reputable manufacturer can't hold tolerances better than that, and if they can't I would question other quality issues like strength of the glass. I think the suppliers (Wicks and Spruce, etal.) should be publishing the manufacturer's name and part number, i.e. West 206 slow hardner, or generic specifications, i.e. type glass, diameter and quantity of strands, preferably relating to some standard testing method like MS, ASTM or DIN. If they are shipping different material than was originally specified and approved without notifying the designer, I would have a real concern. If they are substituting material without concurence of the designer, and advertising it without testing and competent people making decisions, that is improper. Recently I ordered from Wicks Cleveland brake linings, they shipped Rapco, which I returned. I have had good luck with not wearing discs, and didn't wish to push my luck. Also the Cleveland plant is nearby, and I like keeping the money local. Otherwise I don't have any issues with the Rapco product. Date: Mon, 06 Dec 1999 19:47:09 -0500 From: Jeff Russell Subject: COZY: UNI spar tape cdenk@ix.netcom.com wrote: > I just have a hard time believing that a reputable manufacturer > can't hold tolerances better than that, and if they can't I > would question other quality issues like strength of the glass. > I think the suppliers (Wicks and Spruce, etal.) should be publishing > the manufacturer's name and part number. Aircraft Spruce manufactures it in house in Griffin, GA. PS: I forgot to add that ACS does not manufacture the glass, they just sow the 30 rovings together making the 3" tape. Ron Alexander first owned the machine and produce the "spar tape" and sold it to both ACS and Wicks. I saw the machine and learned the problems that went with this machine. The tape should be 3" wide with 30 strands of (rovings) sown together. Any tape that is 2 1/2" wide has the incorrect tension on the cross treads giving the wrong dimension. ACS needs more training on this machine and you can tell them I said so. Builders using this material at 2 1/2" long are forced to remove the cross threads to fill up the spar caps at the correct thickness over the 3". The Long-EZ plans did not have you remove the cross threads. It was found over time that if you removed the threads that you could wet out the roving quicker and pack more in without any pressure applied like (vacuum bagging). Not that choice has be taken from you if the 3" is 2 1/2". If I was still using the spar tape that the plans call out for, I would complain about the narrower size to ACS! The catalog says 3" and that is what it should fit. -- Jeff