Date: Tue, 9 Jan 1996 09:36:20 -0500 From: Marc Zeitlin Subject: Safe-t-poxy type epoxy system available - rec.aviation.homebuilt #16150 Our own (Gordon Bowen) writes (in rec.aviation.homebuilt #16150): |> To: Composite builders |> |> Hexcel Co. decision to sell the Resins Group to HB Fuller has left |> composite homebuilders who like the old Safe-t-poxy systems without a |> source of materials. Also the purchase of Alexander Aero by Aircraft |> Spruce has limited the amount of competitors in the composites materials |> market. |> |> We've decided to make an epoxy system similar to the old Safe-t-poxy I |> and II. The hardeners are EZ-83 (fast), EZ-84 (med.) and EZ-87 (slow. |> The resins are EZ-09 (lower visc.) and EZ-10 (normal visc). |> |> The mix ratios remain 44:100. The technology and materials used are |> similar to the old systems. For legal reason we cannot call them |> Safe-t-poxy but they're are close as you can get and remain legal. |> |> These epoxy systems, fiberglass and foams are available from: |> |> Diversified Materials Inc. |> La Mesa, CA. |> PH- 619-464-4111 |> Ask for Rich Christy |> |> Thanks- Gordon Bowen- Former Hexcel Epoxy Product Manager |> OSHKOSH Composites Workshop Instructor/Coordinator and Composites Forums |> Instructor. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Thu, 18 Jan 1996 07:51:09 -0600 From: Scott Mandel Subject: Epoxy Cleanup Neat trick I learned a few months ago. Get two resealable jars. I'm talking about the glass jars with a glass lid and rubber seal between the lid and the jar, held together by a metal thing. I found some in a craft store but I think they're available elsewhere. Anyhow, fill them about two inches full with MEK. Use one to clean everything. Dunk epoxy, flox, and micro laden stuff, and use the other to store your brushes after you're done dunking. I also use my just dunked brushes to clean squegees, scissors and anyhting else I've gunked up. I've found this acually makes cleanup much easier. I use less MEK, less brushes (Three are still good as new after 2 months), and my wife no longer carps at me for leaving brushes in the freezer. I find I usually don't get much reuse from those freezer brushes anyhow. This has been a winner for me all the way around. Thanks go to, Jim Marshall (a fellow Texas Cozy builder) for showing this to me. _________________ ______________________ / Scott L. Mandel \ /Email: mandel@esy.com \ \_________________/_________________________\______________________/ From: Michael Antares Subject: 2426 epoxy availability Date: Mon, 29 Jan 1996 19:36:20 -0800 Just spoke with Janet at Wicks this morning and she informed me that = starting mid-February they will be carrying the 2426--the RAE = system--epoxy again (which had been discontinued a few months ago by = everyone since Hexcell was requiring a 500 gallon minimum buy). The = timing is perfect for me as I actually had called her to order my first = 2427 and I wasn't looking forward to cleaning out my pump and resetting = the ratio. Date: Sun, 25 Feb 1996 18:22:00 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Resin users Warning............. This is multipart MIME message. --ryntpkjljsyvnfxvkljclfrdrsckui Content-Type:text/plain; charset=US-ASCII; name="NCZ125E.TMP" "text attached" <> (A warning to all) who live in humid climates. --ryntpkjljsyvnfxvkljclfrdrsckui Content-Type:text/plain; charset=US-ASCII; name="resin.txt" AeroCad has used these types of epoxy systems and seen very different results in our testing: Hexcel's RAE 2426 resin & 2176,2177 hardeners Hexcel's EPOLITE 2410 resin & 2183,2184,2187 hardeners Hexcel's EPOLITE 2318 resin & 2316 hardener Hexcel's 2427 resin & hardener PTM&W 3660 resin & PR2032 hardeners (fast and slow) 5 different types CLEARSTREAM EPOXY WEST SYSTEMS 105-5 resin & 205,206 hardeners (for finishing) ALPHA-POXY (for finishing) RYCHOR EPOXY (for finishing) Depending on where you are building your project, North, South, East or West, the climate that your are in will (most effect) the way an Amine Base resin will work for you. The only type of Resin that we have used that's not Amine Based was Hexcel's EPOLITE 2183,2184,2187 hardeners. The bad thing that is this hardener has MDAand Styrene as an additive so they call this a Styrene-Monomer Base. This hardner dissipates water as it's curing so that Amine Blush or other water related problems go away. AMINE BLUSH Amine blush is caused by high humidity and by the amine group in the resins and hardeners accepting C02 and H20. This is noticeable by a white film around the lids of a laminate, or by a thin film that gums up your sandpaper. So often people call and think that their resins are not curing and that they have been supplied faulty materials, but the real culprit is (amine blush) caused by high humidity and high temperatures. As the temperatures increase, the air can carry much higher columns of moisture and carbon dioxide. This, coupled with the temperature increasing the number of reactive sites available, sets up the perfect condition for amine blush to occur. With all this technical goop set aside, most builders only want to know how to prevent amine blush or how to cure the problem that they now have on their laminate. The following are remedies for amine bluish: 1. Use peel ply. Amine blush forms most generally on the outer most portion of the lay-up. By using peel ply the amine blush is removed when the peel ply is removed, leaving a laminate free of amine blush and ready for secondary bonding. 2. Use a high-quality resin, or use a fast hardener. The length of time that resin is uncured is the length of time of exposure for the formation of amine blush. If this time is reduced, so will the amount of amine blush. 3. Cap all resins as soon as possible. This reduces resins and hardeners exposure to the elements that form amine blush. (DO NOT USE EPOXY PUMPS) Humidity in your fiberglass and core material can also produce reactions on how a laminate will turn out. 4. Work in a controlled environment if possible. It is often hard to have a temperature and humidity controlled shop, but we can do our lay-ups at times when the temperature is not 100 plus, and the humidity is not 99% like we frequently see in North Carolina. 5. Amine blush can be washed off with a clean cloth and warm water once the initial cure has occurred. 6. Sanding will remove the amine blush and also gum up your sandpaper. Amine blush must be removed before subsequent or secondary laminates or lay-ups are initiated. If the amine blush is not removed, the intralaminar shear strength is only as strong as the amine blush. I find that the easiest method is to purchase a high-quality resin that is not so susceptible to amine blush and use peel ply. By doing this, I get the best of both worlds. I get a resin that is easy to work with and has higher qualities in virtually every area, and I reduce sanding work and lighten my laminate by using peel ply. With these issues in mind, this is why we only use Hexcel's EPOLITE 2183,2184,2187 hardeners which eliminate the problem of amine blush. We at AeroCad had bad testing results on the Amine Base hardeners. On a glass to glass bond ( tape glassing cured bulkheads in place on to other cured glass) the tape glass would peal off like it bonded to wax paper. We also found plies of glass after full cure, to also have poor peel strength between the plies. Vacuum bagging also produced the same reaction. We deal with 80 to 90 percent humidity in our area most of the time. We feel that you should (always test your resin systems) to see if these types of problems come up. Most of our peel strength problems were seen in the winter time. The longer the cure rate (slower hardeners), the more moisture that seemed to creep in. We had material reps. see what problems we were seeing in our testings, and to our surprise no answers came from them. Our fix is to just use Styrene-Monomer Base hardeners. What happens if we can no longer get this material? --ryntpkjljsyvnfxvkljclfrdrsckui-- Date: Mon, 26 Feb 1996 08:07:37 -0500 From: william l kleb Subject: Re: Resin users Warning............. Jeff S. Russell writes: > > (DO NOT USE EPOXY PUMPS) back to the weighing method? that sounds depressing. > We at AeroCad had bad testing results on the Amine Base hardeners... > Humidity in your fiberglass and core material can also produce > reactions on how a laminate will turn out. > to what extent? this seems to fly in the face of burt's original honey and bed sheets idea of airplane-building that even idiots couldn't mess-up. is amine something that has been introduced since the original RAE epoxies? --- bill kleb (w.l.kleb@larc.nasa.gov) 73 bellanca 7gcbc citabria 99 kleb cozy iv Date: Mon, 26 Feb 1996 16:37:35 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Re: Resin users Warning............. remember Bill, RAF is in the desert with almost no humidity Use all resin as if your the Guinea-Pig in your area. With this in mind you will find the resin that works the best for you. Date: Mon, 26 Feb 1996 16:58:36 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Fwd: Re: Resin users Warning............. ---- Begin Forwarded Message Jeff S. Russell writes: > > (DO NOT USE EPOXY PUMPS) back to the weighing method? that sounds depressing. > We at AeroCad had bad testing results on the Amine Base hardeners... > Humidity in your fiberglass and core material can also produce > reactions on how a laminate will turn out. > >to what extent? this seems to fly in the face of burt's original >honey and bed sheets idea of airplane-building that even idiots >couldn't >mess-up. is amine something that has been introduced since the >original RAE epoxies? remember Bill, RAF is in the desert with almost no humidity. Use all resins as if your a Guinea pig in your area. test, test, test untill you know the resin will work for needs in your area. We also found that the TG was not always what the Resin Manufacture said it was. We took nose struts made out of S-2 glass and sample Resin from manuf. and post cured, slowly stepping up to 190 deg. We would then let cool, and reheat to 160 then 170 and so-on untill the resin became rubbery. Some would only reach 160, and others maybe 180. Our the Resin Manuf. lying to us as end users. They told us to expect 10-20 percent less TG becouse we were not in THEIR lab. If that's the answer that you can expect from them. You best TEST - TEST - TEST Date: Tue, 27 Feb 1996 05:06:14 -0800 From: aerocad@ix.netcom.com (Jeff S. Russell) Subject: Fwd: Re: Resin users Warning............. ---- Begin Forwarded Message To: aerocad@ix.netcom.com (Jeff S. Russell) From: Greg Smith Subject: Re: Resin users Warning............. Dear Jeff, I concur with your opinions on the amine based products....have also gone back to 2410/2184 system. That 2427 stuff just isn't what it's cracked up to be, at least in my neighborhood. I didn't have much luck with soap and water to remove heavy deposits of the blush (when I used 2427); chipping it off with a scraper and then following up with a good sanding seemed to do the trick, although a lot of tedious, unnecessary work (if I had used the right stuff in the first place). Just thought I'd drop you a note and let you know that all the cores, spars and strakes arrived with no damage to the parts. A little shipping rash here and there from handling in a warehouse but everything checked out fine upon unpacking. I am very impressed with the quality of these parts....you guys do great work! Thanks again for handling that little last minute freight bill misunderstanding.... Best Regards, Greg Smith Date: Tue, 27 Feb 1996 15:55:50 -0500 (EST) From: Tech Support - Rick Subject: Re: Fwd: Re: Resin users Warning............. I am using 2427 here in Raleigh, NC. The only problems I had initially, were the fact of the long cure time and gumming in the first 24 hours. After that it cured totally hard with no peel. But, I solved that with a parts bake oven. four hours and hard cure. my thoughts are my own and all that jazz. but anyway, gotta go, flying and scuba diving jerk my chain. Rick Date: Wed, 06 Mar 96 12:05:34 est From: "Larry Schuler" Subject: 2427 Epoxy Anyone used both RAE and 2427? What are the key differences? I am planning to do complete MKIV with 2427 unless some of you "experienced" forlks can tell me why I might re-consider. My understanding is that 2427 is easier to work with and can be post cured @ about 160 Deg. Thanks for advice in advance. Larry Date: Wed, 6 Mar 1996 19:08:34 -0500 From: JQUESTCOZY@aol.com Subject: Re: 2427 Epoxy I used RAE "fast" up until the nose section when Wicks informed me they would no longer carry it. Some comparison: Advantage:The 2427 I would say wets out a little better (more or less viscous, I get them mixed up, anyhow, flows nicer) Disadvantage: 2427 is a little more transparent where RAE fast was "greenish" It seems more difficult to spot lean areas or bubbles with the 2427. It takes longer to cure than what I'm used to with the RAE. I could normally do a layup over a piece I did the day before with RAE, 2427 still will not sand without gumming the sandpaper. Should you switch? One better than the other? I think you'll get a lot of opinions, either one is fine. If I knew Wick's would start to carry RAE again or never stopped I most likely would be still using the RAE. Just my 2 cents worth. You can check the archives on the subject of epoxy for further experiences from other builders.:-) John Wilemski (JQUESTCOZY) Date: Thu, 7 Mar 1996 00:30:01 -0500 From: JHocut@aol.com Subject: Re: 2427 Epoxy I've been using 2427 and have no complaints at all with it. I understand how a few people like a resin system that cures faster, but I personally find the fact that 2427 cures slower to be a blessing. I get the temperature in my shop down to 65 - 70 and have plenty of time to do layups, then crank it up to about 80 to speed up cure. Lately instead of heating the entire shop to 80 I've been aiming shop lamps w/ a 75 or 100 watt bulb at the area that needs to cure, this gets the local area up to about 120 or 140 and really speeds up cure (and the resin cures stronger than at room temperature from what I understand). I've heard of some people having a problem w/ 2427 in that after several hours you can't add to a layup because of poor adhesion (that's been discussed here a couple of times - I've noticed that the resin in a container will "skin" after a sufficient length of time, I believe that's what's happening in these layups also). The solution is to plan ahead, and wherever you can't get the next layer of glass on in a couple of hours peel ply and finish the next day. I've also worked w/ some of the other resin systems, and find the smell of 2427 to be MUCH less objectionable (virtually nonexistant in fact). 2427 wets out a bit better also, because of it's lower viscosity. To make a short story long, I think 2427 is just great, and have had no problems at all with it. Jim Hocut Cozy IV # 448 Date: Thu, 07 Mar 1996 07:30:43 -0600 From: tims@enet.net (Tim Sullivan) Subject: Re: 2427 Epoxy "Larry Schuler" writes: > What are the key differences? > > I am planning to do complete MKIV with 2427 unless some of you > "experienced" forlks can tell me why I might re-consider. > > My understanding is that 2427 is easier to work with and can be post cured > @ about 160 Deg. I, like many others,am using 2427. I started with safety epoxy II but switched after the first gallon. The 2427 is easy to work with BUT terrible with locating stray air bubbles esp under peel ply. my $0.02 Tim Sullivan (tims@enet.net) Phoenix, AZ | * | Cozy MK IV Builder #470 |-----(/)-----| The journey begins 8/10/95 / \ Current Status: Ch 9 o o Date: Thu, 7 Mar 1996 09:45:00 -0500 From: Dick.Finn@FNB.sprint.com Subject: Re: 2427 Epoxy I used RAE through the whole process. It has a bluish green color which makes it easier to spot dry spots or bubbles on the layup. I understand 2427 is transparent. This, to my way of thinking, is not a show stopper but is a major advantage. The RAE is nearly odorless. Again, not a show stopper but when working in the basement it is a big plus. I friend who uses Safty-poxy had his wife evict him from his basement due to the smell. He is now working in the garage. Even though it is heated it still gets chilly out there in a Chicago Winter. I'm not sure but I believe the RAE is more toxic. I do take great care with barrier creams and gloves. Dick Finn Cozy Mark IV #46 ______________________________ Reply Separator _________________________________ Subject: 2427 Epoxy Author: lschuler@cellular.uscc.com at INTERNET Date: 3/6/96 2:04 PM Anyone used both RAE and 2427? What are the key differences? I am planning to do complete MKIV with 2427 unless some of you "experienced" forlks can tell me why I might re-consider. My understanding is that 2427 is easier to work with and can be post cured @ about 160 Deg. Thanks for advice in advance. Larry Date: Thu, 07 Mar 96 10:42:57 est From: "Larry Schuler" Subject: Re[2]: 2427 Epoxy Neat idea with the heat lamps. I am in Wisconsin, similar shop heating problems.... finished building the shop in December. I keep it at about 45 or 50 (currently inactive) and wife is already complaining about the gas bill! [Wait till she sees next winter's bill] Wouldn't the lamps cause some hot-spots {un-even heating}? I was thinking about making a heat box (oven) out of insulating wall board and use a fan-driven space heater (electric), or similar, to circulate and even out the temp with some strategicly placed thermostats and a step-up controller (which I will make myself). I talked with Gordon and Bailets at length last Oshkosh and both had suggested that a post cure @ about 160 Deg is right for the foam/epoxy (2427) and would push the finished Tg up well over 250 Deg. Gordon said NOT to raise the temp more than 5 deg per minute; and was refering to "POST-CURE", not the initial cure. This all translates to the possibility of something other than white paint on the finished plane {but not black} while not having to worry about sagging wings when parked in the Arizona sun. Bailets suggested the insulation board; said he uses it all the time. Anyone tried vaccum bagging? I know it will cost a bit more, but maybe help with weight a bit and help with the "Blush" problems. Larry ______________________________ Reply Separator _________________________________ Subject: Re: 2427 Epoxy Author: JHocut@aol.com at INTERNET Date: 3/7/96 12:33 AM Lately instead of heating the entire shop to 80 I've been aiming shop lamps w/ a 75 or 100 watt bulb at the area that needs to cure, this gets the local area up to about 120 or 140 and really speeds up cure (and the resin cures stronger than at room temperature from what I understand). Jim Hocut Cozy IV # 448 From: Marc J. Zeitlin Subject: Re[2]: 2427 Epoxy (fwd) Date: Thu, 7 Mar 96 18:32:55 EST Larry Schuler wrote: > .............. I talked with Gordon and Bailets at > length last Oshkosh and both had suggested that a post cure @ about 160 Deg > is right for the foam/epoxy (2427) and would push the finished Tg up well > over 250 Deg. Gordon said NOT to raise the temp more than 5 deg per > minute; and was refering to "POST-CURE", not the initial cure. Wow - this seems to go against everything Gordon Bowen said in his lecture their, as far as I remember. I got the impression (and I talked to him individually for about 1/2 hour) that there was some maximum Tg that you could get with a particular epoxy, and that it would be about 40 deg. F above the post-cure temperature, up to some maximum. I got the impression that the maximum for the epoxies we use (RAE, SP, etc.) are all about 170 deg F, so that postcuring above 130-140 deg F wouldn't get you anything. I've NEVER heard anything as high as 250 deg F. I'd really like to see something documented on this, rather than just Larry and I trying to remember what someone else said 8 months ago. > ............. This all > translates to the possibility of something other than white paint on the > finished plane {but not black} while not having to worry about sagging > wings when parked in the Arizona sun. I wouldn't chance it. I'd like to stay as far away from Tg as I can, especially if the max. Tg is 170 deg. F. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Fri, 08 Mar 1996 08:44:23 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: Re[4]: 2427 Epoxy (fwd) >Wow - this seems to go against everything Gordon Bowen said in his > lecture their, as far as I remember. I got the impression (and I talked > to him individually for about 1/2 hour) that there was some maximum Tg > that you could get with a particular epoxy, and that it would be about 40 > deg. F above the post-cure temperature, up to some maximum. I got the >impression that the maximum for the epoxies we use (RAE, SP, etc.) > are all about 170 deg F, so that postcuring above 130-140 deg F > wouldn't get you anything. I've NEVER heard anything as high as 250 deg F. I'd >really like to see something documented on this, rather than just Larry >and I trying to remember what someone else said 8 months ago. Its interesting that we found on our testing of Tg on each epoxy that we tried was around 160 to 190 deg. The only epoxy that we found to have a higher one was the Epolite systems. It had a max. Tg of 250 deg. F. We asked the Hexcels lab on what's the differents on them and we got the answer that this systems seems to super harden when it reaches this temperature. This resin system states its Tg is 190 deg. Is this a good find, insted of what seems to be the normal LESS THAN (what they say it will do). I think this gives us a better pucker facter then other systems if heat is an problem. We now only use this in our Main gear struts for fear of the dreaded heat. hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Fri, 08 Mar 1996 07:40:29 -0600 From: tims@enet.net (Tim Sullivan) Subject: Re: Re[2]: 2427 Epoxy (fwd) Marc wrote: >Wow - this seems to go against everything Gordon Bowen said in his lecture >their, as far as I remember. I got the impression (and I talked to him >individually for about 1/2 hour) that there was some maximum Tg that you >could get with a particular epoxy, and that it would be about 40 deg. F >above the post-cure temperature, up to some maximum. I got the >impression that the maximum for the epoxies we use (RAE, SP, etc.) are >all about 170 deg F, so that postcuring above 130-140 deg F wouldn't get >you anything. I've NEVER heard anything as high as 250 deg F. I'd >really like to see something documented on this, rather than just Larry >and I trying to remember what someone else said 8 months ago. I have to agree with you marc. I took the Alexander Advanced Composites course and they reiterated that about 40F above cure temp is all you can safely apply before a "melt" down starts. Stay with white wings (esp. me here in AZ). Tim Sullivan (tims@enet.net) Phoenix, AZ | * | Cozy MK IV Builder #470 |-----(/)-----| The journey begins 8/10/95 / \ Current Status: Ch 9 o o Date: Fri, 08 Mar 1996 15:32:17 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: [7]: 2427 Epoxy Larry S. asked: >Is the 250 Deg max Tg for Epolite you mentioned obtained by elevated >temperature cure/post-cure, or room temp cure only? Post cure only. >If elevated cure/post-cure, could you describe the method/step/ramp >etc. that you use? We have a 500 deg. oven. We let the part (one day) cure at room temp. Insert in oven at 120 deg. for 2 hours, then we go to 140 deg. then 160, 180, 200, two hours at a time thus (the ramp process) This is a 10 hour oven job. We let the part slowly go down in temp. (A day later, To check what we now have for Tg). Raise the temp back up to what softens the harden resin and (presto) You found the max temp. Tg AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Fri, 08 Mar 96 11:55:51 est From: "Larry Schuler" Subject: Re[6]: 2427 Epoxy (fwd) Jeff, Thanks for your input; you have been a very welcome addition to this group. I believe the higher Tg you described was what Gordon was referring to; but, I am fairly certain that the Tg wouldn't go that high without a post-cure. In other words it is of little benefit until, for example, the gear legs get hot once (hopefully 'before' being mounted on the plane). Is the 250 Deg max Tg for Epolite you mentioned obtained by elevated temperature cure/post-cure, or room temp cure only? If elevated cure/post-cure, could you describe the method/step/ramp etc. that you use? Thanks Larry Date: 09 Mar 96 07:12:30 EST From: "William E. Buckley" <74744.2301@compuserve.com> Subject: Epoxy I was wondering how much of a difference it makes on a layup if the temperature is allowed to fall over night. Will the strength be harmed if I let the garage fall back into the 40's overnight after finishing a layup? It obviously cures slower. I'm using 2427 by the way. I've never read anything saying this creates a weaker structure; just a slow curing one. Wishfull thinking on my part or not? William E. Buckley #437 74744.2301@compuserve.com From: Marc J. Zeitlin Subject: Epoxy (fwd) Date: Mon, 11 Mar 96 9:13:09 EST William E. Buckley asks: >I was wondering how much of a difference it makes on a layup if the >temperature is allowed to fall over night. ......... I've never read >anything saying this creates a weaker structure; just a slow curing one. You've got it right - just slower. Cured is cured, within the temperature ranges we're discussing. Assuming that you eventually post-cure all the stressed components (like you should), you would have no measureable strength difference in your parts (actually, even if you DIDN'T post-cure, eventually the parts would be identical). -- Marc J. Zeitlin Email: marcz@an.hp.com From: Michael Antares Subject: RE: Epoxy Date: Mon, 11 Mar 1996 09:05:01 -0800 I was wondering how much of a difference it makes on a layup if the = temperature is allowed to fall over night. Will the strength be harmed if I let the = garage fall back into the 40's overnight after finishing a layup? It obviously = cures slower. I'm using 2427 by the way. I've never read anything saying this = creates a weaker structure; just a slow curing one. Wishfull thinking on my part = or not? William E. Buckley #437 I'm not providing any answers but can add a comment that I'm doing the = same thing. Some structures that I've done a long time ago seem to be = cured just fine although they did go through the cool night routine. I = do however warm the garage up to at least 60 degrees while I'm doing the = layups (I'm using 2426 epoxy). To add a comment on the high temperature cures. Going back to my = aerospace days including man-rated NASA equipment, epoxies were cured at = 140 degrees for maximum strength. AND I do not purport to be any kind = of a knowledgeable person in this regard--this is only anecdotal = evidence! Michael Date: Mon, 11 Mar 1996 18:19:48 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: Epoxy >I was wondering how much of a difference it makes on a layup if >the temperature is allowed to fall over night. Will the strength >be harmed if I let the garage fall back into the 40's overnight after >finishing a layup? It obviously cures slower. I'm using 2427 by the way. >I've never read anything saying this creates a weaker structure; >just a slow curing one. Wishfull thinking on my part or not? > >William E. Buckley #437 Don't forget that the longer it takes to reach the jell time (B stage) the more moisture that can be picked up in the layup. If you are using slow hardeners or just in cooler climates where temps can be a problom. Use a plastic drop cloth (like a tent) and a room heater. You will see much better curing times with little cost needed to do this. This will some what post cure your parts Better than none? AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 11 Mar 1996 18:44:28 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: Epoxy I forgot to add that we are TRYING some different PTM&W reasin systems. They are still trying to get us to use their stuff. We made some small parts and let them cure overnight turning the heat down to 55 deg. We also made some small parts that were made from 2410/2184. the same time. The next morning the PTM&W was almost still wet and the 2410 system was hard as a rock. The heat was turned on to 70 deg. for at least 8 of our working hours and the P resin still only got to B stage. Two days later. The same thing. On the forth day we post cured the P parts to 140 deg., and it got hard after the oven bake. PTM&W Called me today and asked me what I thought and after telling him what the coolness did he said that that resin system NEEDS post curing. Nice to now know? hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 18 Mar 96 19:10:26 est From: "Larry Schuler" Subject: Re[5]: 2427 Epoxy (fwd) On 8 Mar 1996, Bill Walsh wrote: >Just a note....a story Stan Montgomery told me was about his experience in trying to get the optimium in post cure. He elevated the heat over 180 degrees for quite a few hours ...only to find that he had melted all of the foam. 250 degrees seems excessive. I post cured to 140 degrees per Stans recomendations. Bill Walsh >>Bill, I'm not surprised it turned to mush on him since the blue foam Tg is 180 Deg. That's why Gordon recommended 160 Deg post cure as highest safe temp for epoxy/foam combo most of us use. Also not more than 5 deg rise per minute helps to prevent hot/cold spots {slower rise is ok, but faster is a bad thing}. Date: Tue, 19 Mar 1996 22:18:56 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: [6]: 2427 Epoxy (fwd) >On 8 Mar 1996, Bill Walsh wrote: >Just a note....a story Stan Montgomery told me was about his >experience in trying to get the optimium in post cure. He >elevated the heat over 180 degrees for quite a few hours ...only to find >that he had melted all of the foam. 250 degrees seems excessive. I >post cured to 140 degrees per Stans recomendations. Bill Walsh >Bill, I'm not surprised it turned to mush on him since the >blue foam Tg is 180 Deg. That's why Gordon recommended 160 Deg post cure >as highest safe temp for epoxy/foam combo most of us use. Also not more >than 5 deg rise per minute helps to prevent hot/cold spots {slower rise >is ok, but faster is a bad thing}. AeroCad writes: Don't forget that the PVC foams can take a much higher temp. 290 + to bend or reshape. The Last-a-foam also has a higher temp than the Extruded PS foam thats in our wings/canards. So if you are post curing wings/canards 140-150 max so not to cook the foam. We also heard of a Cozy having a heat meltdown in the wing and main spar becouse of an exhaust crack of some sort. The repair was to replace the melted foam and glass with pour foam and new glass. My question is what about the resin that got baked at 300 + deg on the rest of the main spar and wings. It sounded like the main spar got at least this high becouse the 6 lb PVC foam was twisted when removed. The Resin degrades to being britle this far past Tg? I think to be on the safe side that new wings/main spar would need to be replaced, insted of repaired as such. Does any of the Resin Mfg have a high temp resin test to see if its OK if it gone past its Tg by 100s of deg. I would like to hear from them to keep this person safe than sorry. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Thu, 21 Mar 96 07:52:09 est From: "Larry Schuler" Subject: Re: 2427 Epoxy (fwd) Sorry this took so long; was out of town over a week. Finally found a few of my notes (in my wallet.... I'd say under my nose, but that would be realy "stretching" it). First a few caveats: 1. I have not started yet. 2. I purchased plans set #500 (nice number and milestone for Nat). 3. I have some materials ordered. 4. My name is Larry Schuler and I live in Wausau, Wisconsin; please don't confuse me with some "bad vendor named Larry in Wisconsin"; I don't sell anything; but, I will gladly give away my experiences for the learning benefit of others (I tend to make some really dumb mistakes, so I try to get very cautious, but tend to learn more from the dumb ones). 5. I have not TESTED anything yet; at this point all I can do is repeat what I have learned from those experienced folks that have been there. My notes were from lengthy conversations I had with both Bowen and Bailets outside the forums {Sorry, my notes don't say which one said what}. The discussions were centered around epoxys and how to get a higher Tg to combat sag. They both said that sag should not be a problem with 2427 as long as the plane is white and has a good UV primer. Here are my notes (verbatum) take 'em for what they are worth; they seem to "generally" agree with what Jeff has posted here. - Use 2427 newer formula than RAE - saftypoxy ok if necessary but not as good - 2427 better stress comp., tens., + tough. [I was refering to Tension, compression and toughness] - higher Tg at cure - easier to wet out - hard to get bubbles out - pay attention - vac bag if possible - gets bubbles out and excess resin - post cure at 140 to 160 - 160 cure gets ~ 240-250 Tg [glad I found the note; doesn't say "well over 250" as I stated before {one of those 'dumb mistakes' I was talking about}] - step or ramp <= 5 deg/min - hold high temp for even heating (1/2 - 1 Hr) - Ramp/step down - no shock/spot cool - Tg blue styro is ~180, be careful melt-down - all other foams in czy >180 Tg - cheap oven use insul. sheath - heat lamps spotty - circulate heat evenly - indirect heat source (not on one spot) - test EVERYTHING! Thats what I have for what it's worth. I intend to "try" (ie. experiment and test). My main goal is to reduce the chance of sag over the years so I don't always have to worry about hanger space. There may be a "possible" side benefit of "maybe" using a color other than white. The last note I took from them says it all...... I will be more than happy to share what I learn along the way. Larry Date: Thu, 21 Mar 1996 18:03:22 -0800 From: harvey3@ix.netcom.com (Neil K. Clayton) Subject: 2427 "Epolite" warning I bought 2 gall of 2427 Epolite from Wicks about 2 weeks ago. I didn't use it immediately 'cos I still had some 2410 left. Yesterday I cleaned my dispenser thoroughly and went to refill it with 2427. I noticed the hardner can was cloudy and had what appeared to be crystals floating in it. I examined it further by cutting the top off the can with a can-opener instead of peering through the cap hole. It was still the right orange colour, but had a skin on the top and particles floating in it. It was too opaque to see the bottom of the can. It didn't feel right, so I called Wicks. Long story short, I got a run around (Rosalie; "it'll be a few days before I can get back to you..." - not like Wicks) so I called Hexcel direct. Spoke to a chemist called Eric someone. He said he knew what it was....it had been contaminated with carbon mon (or di-) oxide from the atmosphere because it didn't have nitrogen pumped into the can above the liquid after manufacture. He said don't use it! He'd have Wick's called and tell 'em. I checked the other can I bought and it was the same. Batch number CEHE066 Don't use it if you have any. Neil Date: Fri, 22 Mar 1996 14:31:46 -0500 From: william l kleb Subject: 2427 epoxy humidity effects (was Re: (2) 2427 warning) Jeff Russell writes: > > This is the same thing that will happen when you leave this type resin system in a > epoxy pump exposed to humidity. As soon as you open the container (Time is ticking) > i am confused by this... why is keeping your epoxy in the can any better than an epoxy pump reservoir? an epoxy pump is sealed as good as any can, except for the small bit exposed in the end of the dispensing tube. are you suggesting that the humidity travels up the tube, contaminating the entire reservoir? couldn't one just "pour-off" the first bit in the dispensing tube as one does with any soft-serve ice cream machine? according to your statement, it seems that once you open a can of resin, you have to use the entire thing very quickly, because you have let "regular", humid air in the can, just as when you refill an epoxy pump. maybe we have to buy a bottle of argon (or some suitable inert gas), and back-fill the epoxy pump reservoir (or can) before we re-seal it? my earlier point about rutan and his philosophy of "even an idiot can do this and not go too wrong" was that i am surprised that RAF would un-categorically approve a resin system, say 2427, and not have considered humidity effects. i know they are located in the desert, but they usually seem to have a very open, safety-conscious, global outlook. maybe the word just hasn't gotten to them yet? regardless, your point of test, test, test is well taken. --- bill kleb (w.l.kleb@larc.nasa.gov) 73 bellanca 7gcbc citabria 99 kleb cozy iv Date: 23 Mar 96 22:22:00 EST From: "Edmond A. Richards" <103235.1336@compuserve.com> Subject: 2427 Epoxy humidity effects On March 22nd Bill Kleb writes: An epoxy pump is sealed as good as any can.... -------------------------------------------------------------------------- The epoxy pumps that most of us are using have only "Tupperware" style containers to hold both the resin and the hardner. This seems to me to be far less a container than the metal can that the material is distributed in. Also if you look closely, there is a hole in the lid of each container to let air in as the resin is drawn down. As far as moisture sensitivity of the 2427 epoxy. I became conserned when I read the caution statement on the can. It clearly states if the can is opened, the air that is introduced into the cotainer must be diplaced with dry nitrogen before re-capping. This conserned me enough to replace the "tupperware" tanks on my epoxy pump with metal cans with sealed lids and a dry nitrogen purge. ( I live in Florida, moisture is a way of life). I only used about 1 1/2 gal. of the 2427 then switched back to Safe-T-Poxy II. While using the 2427 I saw many of the problems that Jeff Russell describes in his discussion of the subject. I don't feel too bad about the parts I made with the 2427 because at the time I was working mostly on the interior (seats, armrests, etc.) and micro for filler. The only major pieces I made with it were the winglets. Although I did use Safe-T-Poxy II to attach them to the wings. I'm sure the 2427 epoxy is OK but I just didn't feel right about using it. However I still have the metal tanks and the nitrogen purge system on the ratio pump. It keeps the Safe-T-Poxy II just as fresh as a daisy for months. Date: Mon, 25 Mar 1996 08:55:34 -0500 From: Phillip.Johnson@Lockheed.on.ca (Phillip Johnson) Subject: 2427 Epoxy humidity effects Edmond A. Richards writes: > This conserned me enough to replace the "tupperware" tanks on my > epoxy pump with metal cans with sealed lids and a dry nitrogen > purge. ( I live in Florida, moisture is a way of life). I took a different approach: After I fill the "Tupperware" tanks I place a plastic bag over the open top then replace the lid of the tank. The bag is sufficiently large to completely fill the container when it is empty. The bag is arranged to be on top of the resin/harder at the time of filling. As the fluid is used, the bag moves down to fill the void without introducing more air over the fluid. The resin is always fresh and doesn't need fancy Nitrogen etc. Phillip Johnson Date: Tue, 26 Mar 1996 22:31:52 -0500 From: Fritzx2@aol.com Subject: 2427 Hardner Batch CEHE066 In a message dated 96-03-24 part of Neil Clayton's response to John Wilemki: > It was a chemist at Hexcel who >told me not to use it. His name was Eric (something). Hexcel's # is >(818) 882-3022. He did not specifically say "don't use batch #CEHE066" >but DID tell me not to use the bad stuff I'd received. You might want >to call Eric yourself about the entire batch. It sounded like the stuff >went bad during manufacturing. I too recently (in the last couple of weeks) got a 1 gallon kit of 2427 from Wicks. After reading the message from Neil that he had some bad hardner, I checked my hardner. Mine did not have a skin on the top nor did I see any crystals suspended. The color was as usual, and I could see all the way down to the bottom of the can while shining a light down through the hole. I did however see some very thin layer of sporatic milky clusters on the bottom of the can about 1/8 " thick the size of a dime. To tell you the truth, I never really looked inside the hardner can before so I don't have anything to compare these observations against. I think I will from now on when I get a new can. Since I do not use a pump and must rely on the can to contain the hardner, I therefore cannot "pop the top". I drew a 4 oz. sample and inspected it closely. I could not see any abnormalities. Has anyone else who got this batch inspected theirs? If so, what did you find? I am about to glass the fuse bottom with this batch of resin and hardner and would hate to find out afterwards that there was a problem even though I couldn't tell by looking at it. I'll probably give the Hexcel rep. a call tomorrow also. John Fritz Fritzx2@aol.com Date: Fri, 29 Mar 1996 12:16:23 -0500 From: JHocut@aol.com Subject: Re: 2427 from Wicks In a message dated 96-03-28 23:09:30 EST, HARVEY3@IX.NETCOM.COM wrote: >Funny stuff...I've never used it before. No smell, & when mixed with >flox or micro it looks the flower & water glue we used for papier mache >when we were kids. Seems to go "off" in a hurry - I laid some up at >4.00PM and it was hard enough to prod by 9.00. I've pretty much been using 2427 exclusively, although have used a little Safe-T-Poxy and some West (not for structural stuff, of course). The biggest factor in how fast 2427 (or probably any epoxy for that matter) sets up is temperature. If I'm doing a big layup and need plenty of time I'll get it down to about 65 to 70 in my shop (small shop so it's easy to control temp), and I've got plenty of time. Want it to cure faster to be able to work on something, crank the temperature up. Like Nat says in the plans, temperature is an important tool at your disposal, and be sure to have a wall thermometer in your shop. BTW, if you want to see FAST - try the West with the fast hardener at about 80 to 85 degrees. You've got about 10 minutes to do what you need to do, it's hard in a couple of hours. Jim Hocut jhocut@aol.com Date: Sat, 30 Mar 1996 12:32:57 From: JRaerocad@gnn.com (Jeff Russell) Subject: new epoxy I have used the replacement EZ83 / EZ10 this replaces Safty- epoxy (I). It seems to work the same as the old stuff. Same thickness, yellow color instead of brown or brownish green. cures the same time, no blush at 90% humidity. need to do Tg testing ASAP Things look good so far. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 01 Apr 1996 14:41:13 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: "Hard Shell" Layups Jim Hocut writes: >2) In regards to final finishing, does West or Alphapoxy have any >advantage over 2427 (besides the fact that Alphapoxy costs a little less)? The West systems come in fast or slow hardeners. Alphapoxy and 2427 only has one speed. The west sys. seems soft when cured (If I can print it with my thumb nail, Its too soft) Alpha and 2427 don't have this problem. Alpha is cheaper and EZer to sand with no (bad drugs) inserted to get this result. I have heard that RAF disapproves using alcohol with Epoxy resin. Its degrading strength. Alcohol with the use of micro where strength is not an issue should not be a problem. >Obviously the point would be reached where the strength of the resulting >material would be unacceptable. Ditto on that: AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 01 Apr 1996 16:57:31 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: layups colors >Have you or do you know of anyone who has tried adding a dye/color >to 2427 to help with the bubble problem? Tim, Hexcell told us that an additive could be used. They had one, but I don't remember what it was called. I sure that Gorden B. knows. PTM&W always used dye when we ordered from them. (dark brown) I have also used food color (one drop per 10 oz.) AFTER I MIXED the resin/hardener together so it had some color. I could not tell any differance in the epoxy after it cured. hope this helps AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com From: "Daryl H. Lueck" Subject: mixing RAE hardners Date: Fri, 5 Apr 1996 13:36:25 -0000 I'm all set to cover the second wing this weekend and discovered I won't = have enough RAE Slow hardner. I've got about half a quart in the pump, = not enough to finish the top of the wing. =20 I have 3 quarts of the RAE Fast though. Here's the question du-jours: Can I mix RAE Fast and RAE Slow in the pump, or do I need to clean the = pump after using up the slow? Can I use up the Slow on the first 2 glass layers, then use the Fast for = the third layer? Is it ok layup fast over slow or do the layers have to = cure first???? Help!!!!! Thanks much, Daryl Lueck Cozy Mark IV #243 Date: Sun, 7 Apr 1996 09:29:29 -0400 (EDT) From: Tech Support - Rick Subject: Re: mixing RAE hardners Clean the pump, because , otherwise, your cures go wierd. But it is permissible to layup over the slow with the fast. Rick > > I have 3 quarts of the RAE Fast though. Here's the question du-jours: > Can I mix RAE Fast and RAE Slow in the pump, or do I need to clean the pump after using up the slow? > > Can I use up the Slow on the first 2 glass layers, then use the Fast for the third layer? Is it ok layup fast over slow or do the layers have to cure first???? > > Help!!!!! > Thanks much, > Daryl Lueck > Cozy Mark IV #243 > > Date: Mon, 8 Apr 1996 18:55:01 -0400 (EDT) From: Tech Support - Rick Subject: Alcohol and epoxy dangers! Gentlemen, A word of caution from the materials science dept at NC STate Univ. I checked into this idea of epoxy and alcohol together. The response was overwhelming against the idea at all. These reasons being were similar. 1) alcohol can through gloves were epoxy can not. Also, if the alcohol/epoxy mixture were to get to the skin, the alcohol will induce the epoxy straight to the blood stream, precipatating an alllergic reaction onset faster than normal. 2) Alcohol also outgasses very quickly. This gas formation with the epoxy outgas also leads to extreme sensitivity to epoxy odors. 3) Alcohol seriously degrades almost all known epoxy, whether cured or uncured. Read this in strength, tensile, and elasticity abilities. That is what I have learned, more later as I uncover it. Rick Crapse 919-851-1557 Date: Mon, 8 Apr 1996 19:11:40 -0400 From: Fritzx2@aol.com Subject: Re: Safe Epolite 2427 disposal Harvey3 wrote about disposing of his 2427 epoxy: >Any known neutraliser? I could call the state Haz Mat people but I can >imagine how that conversation will go.... You have what you need right there. Mix the stuff in small enough batches so as not to cause a high heat reaction. It might not be good enough to provide the proper strength for your project but since you are only going to toss it anyway, my guess is that it will cure well enough to prevent any hazard. By the way, this is what I do to the little remaining bit I have in each set of cans in order to be a little more friendly to the environment. John Fritz Fritzx2@aol.com From: Marc J. Zeitlin Subject: Alcohol and epoxy dangers! Date: Tue, 9 Apr 96 8:48:38 EDT Rick Crapse writes: >I checked into this idea of epoxy and alcohol together. The response was >overwhelming against the idea at all. These reasons being were similar. While I do not disagree with the facts, I disagree with the conclusion. Here's why: >1) alcohol can through gloves were epoxy can not. Also, if the alcohol/epoxy > mixture were to get to the skin, the alcohol will induce the epoxy > straight to the blood stream, precipatating an alllergic reaction onset > faster than normal. No question. Any solvent (Acetone, MEK, etc.) will do the same. This is why I use Butyl gloves (for chemical resistance) with vinyl gloves (for butyl glove protection) over them. > 2) Alcohol also outgasses very quickly. This gas formation with the >epoxy outgas also leads to extreme sensitivity to epoxy odors. Also true. This is why I ALWAYS wear a carbon filter respirator while working with epoxy. > 3) Alcohol seriously degrades almost all known epoxy, whether cured or > uncured. Read this in strength, tensile, and elasticity abilities. This may be true, but if tests show that peel strength from glass to foam is NOT degraded from the plain (non-alcohol diluted) case, then there is no net loss. A chain is only as strong as it's weakest link, right? If the foam is that link, making the epoxy stronger doesn't help. So far, the evidence seems to show that peel is better, not worse, with hard shelling, even with the alcohol in the epoxy. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Mon, 29 Apr 1996 20:59:50 -0700 From: Eric Westland Subject: Re: COZY: Re: 2427 Hardner Batch CEHE066 John, thanks for the response. When I opened the can, it was crystal clear. I did the top strake layups yesterday and they cured rock hard - all is well. eric Fritzx2@aol.com wrote: > > In a message dated 96-04-28 13:47:22 EDT, Eric Westland wrote: > > >I just got a batch of the same. What did you resolve on this - did the > >harner work fine? Did you call Hexcel and if so, what did they say? I > >have not opened the cans yet, so if there is a problem, I would like to > >know. > > I contacted the Hexcel rep. He informed me that if the hardner > was not milky then there was no problem. My particular > can of hardner was just fine. I will always carefully look > inside though before using a new can. Since I don't use > a pump I hadn't looked inside before. I would have noticed, > I'm sure, when I poured it into my cup at time of use but that > would have been a BAD time to find out in the middle of a layup. > > John Fritz Fritzx2@aol.com From: UYFA59A@prodigy.com ( JAMES J CULLEN IV) Date: Tue, 28 May 1996 11:48:24, -0500 Subject: COZY: Fiber-Resin Lot #CEHE066 -- [ From: James J. Cullen, Ph.D. * EMC.Ver #2.10P ] -- It was with considerable interest that I followed the series of discussions regarding the alleged `bad batch' of Fiber-Resin's Epolite 2427 Epoxy bearing lot number CEHE066 -- especially as I had purchased four gallons of the material in preparation for constructing my wings. As the discussion progressed, it became apparent that no resolution was ever reached as to whether the lot in question was actually bad. Neil Clayton had his material replaced by Wicks with material from the same lot number and Neil reported that the replacement material appeared to be good. John Fritz observed crystals clumped at the bottom of one of his hardener cans and wondered whether this was a problem. Without a definitive statement from Fiber-Resin or Wicks, I was reluctant to use the material I had received and no-one ever posted a final resolution of the matter to our discussion group. Accordingly, I called Wicks last week and asked them what the status was. Janet and Rosalie promised me that they would contact Fiber-Resin to get a final resolution on the matter. Less than two days later, Rosalie faxed me a copy of the following letter from Fiber-Resin, with a request that I post the letter to the group. Please forgive any spelling errors -- my fax isn't the greatest: Fiber-Resin Corp. 20701 Nordhalf St. Chatsworth, CA 94311 Rosalie Thiems Wicks Aircraft Supply Co. 410 Pine Street Highland, Illinois 62249 Fax: 618-654-6253 Dear Rosalie, It was a pleasure speaking with [you] regarding the FH2427 A&B resin system. The technical laboratory personnel at Fiber-Resin Corporation in Chatsworth, CA have investigated and reviewed the quality history of both the part A and the part B as well as specifically retesting our retain and stock of the FH2427B lot # CEHE066. All of the results and retesting confirm the original Q.C. test data indicating that the material is in specification. This supports your observations of your stock that the material is fine. I would like to reconfirm that in handling all resin systems, it is very important to keep the containers tightly sealed except when dispensing material. This helps to keep expose [sic] of the material to air, humidity and other possible contamination down to a minimum and maintain the product physical properties and storage life. The FH2427 resin system may be slightly more sensitive to air and/or humidity than other resin systems such as those that contain styrene and/or MDA. This is a trade-off for the significant safety and environmental advantages of the FH2427 resin system. One way to maximize the quality and storage life of FH2427 resin system and for that matter any resin system is to displace the air and humidity from the container headspace each time the container is closed using some form of dry gas such as nitrogen or FH8440 "Burp" available in aerosol cans. We periodically receive inquiries from users of FH2427 as well as users of other resin systems concerning a wet lay-up laminate not looking or curing correctly (too brittle or too soft), resin or hardener not looking right (cloudy, off color, etc.) or the resin not wetting out the fiberglass. In almost every situation the problem relates to techniques and procedures. Mix ratio of the part A and part B must be accurate. The resins and hardeners must be kept free of contaminants including air and humidity. The resins and hardeners should be used within the stated shelf life. The fiberglass or other fabric being used must also be kept free of contaminants including humidity and moisture. The application must be allowed to cure adequately to achieve the final physical properties. If we can be of further assistance regarding any of the Epolite products do not hesitate to contact our Customer Service Department. Thank you for your continued interest in Fiber-Resin products. Sincerely, (Signed) Randolph M. Olson Facility Manager So, while we didn't know it at the time, the mad scramble over the quality of lot CEHE066 turned out to be much ado about nothing. That's one of the disadvantages of electronic communications. Sometimes, we tend to transmit messages before we have the opportunity to check our facts. As builders of aircraft, we need to deal in facts, not opinions (unless clearly stated). Remember the old engineering addage: engage brain before mouth. We will never know why Neil's batch appeared cloudy. It may be that the can sat open for too long at Fiber-Resin before being sparged with dry nitrogen This is doubtful. When a company is in a production mode, things tend to get messed up in large quantities -- not just in a single can. As a Chemical Engineer myself, I can state that with the voice of experience. Then again, it may be that Neil had the can open for too long on his bench. This is also doubtful. That's not the way we tend to use the material. We generally just open the can and pour it into the pump's storage container. It may be that the can had an undetected pinhole leak or that the can was damaged in transit. This is possible, I suppose, althought I have never seen it actually happen. In any event, as Nat has taught us (and as Bill Kleb reminded us), **we** are the final quality control inspectors for all materials that go into the construction of our aircraft. If this event has taught us nothing else, it should remind us that **we** must verify the quality of all materials that we receive from our suppliers. Because of the volume of material that they receive, we cannot expect our suppliers to open every can of epoxy that appears on their shipping docks. That responsibility falls on us. I would like to comment that I feel that it is inappropriate for us to contact Wicks' suppliers for information regarding the quality of their products. If we have a problem with materials shipped to us, we should bring the matter up with Wicks (or to whomever we buy them from) and give them sufficient time to resolve the matter. No item is so critical in the construction of a homebuilt aircraft that it can't wait a few days for Wicks to resolve any perceived problems. If we decide to bypass the chain of command and go to one of Wicks suppliers, we can potentially hurt the relationship that Wicks has developed with its suppliers. In the extreme, a supplier might decide that doing business with Wicks isn't worth the trouble of having to field complaint calls from builders. Then, who would we have to deal with to get materials to finish our aircraft? It certainly isn't appropriate to announce that a problem exists before our suppliers have had a chance to check the facts. To do so hurts our suppliers. It may be appropriate to suggest to the group that a problem **may** exist and that you're in the process of trying to verify the problem with our suppliers but, if you decide to do this, make sure that you let the group know that the perceived problem is unconfirmed. I would like to thank Rosalie and Janet for their prompt and courteous attention to this matter. Those of us who have used the material can now rest assured that the epoxy is fine. I am, and always have been, delighted with the courtesy, speed and quality of service offered to me by Wicks. Their employees are knowledgeable, their computers can tell us the status of their stock while we are ordering, they are friendly and they bend over backwards to help us. They have earned our respect and we owe them our thanks. Jim Cullen Cozy Mk IV S/N 0076 (in the nest) Date: Wed, 05 Jun 1996 08:36:54 From: JRaerocad@gnn.com (Jeff Russell) Subject: COZY: COZY epoxy Colors of Resin systems Hexcel's RAE 2426 resin & 2176, 2177 hardeners (Red for fast, Blue for slow) Hexcel's EPOLITE 2410 resin & 2183, 2184, 2187 hardeners (Light to dark brown) Hexcel's EPOLITE 2318 resin & 2316 hardener (clear) Hexcel's 2427 resin & hardener (clear to light amber) CPD's replacement EZ24 resin & EZ83,84,87 hardeners (Dark yellow) Garfield asked >O.K. here are my questions: >1. If 2426 is the old RAE stuff, which is reported to be brownish >or bluish green (depending on hardener used?), if Wicks is going to >carry it again, who is the manufacturer now & is the color the same as >the old, (if not what is the distinctive color?). Jeff's post above >seems to suggest that the old RAE/2426 stuff WAS amine based; is the new >reissue of 2426 subject to amine humidity problems or not? Was the >old? 2426 will still have humidity problems >2. Which of the above systems mentioned by Jeff is the numbers for >what used to be SafeTPoxy I (and II)? And did the old SafeTPoxy I >contain Styrene & MDA? I thought SP II removed these components. SafeTPoxy I 2410/2183 or EZ10/EZ83 contain Styrene & MDA SafeTPoxy II 2410/2184 or EZ10/EZ84 contain Styrene & MDA AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Wed, 05 Jun 1996 10:22:55 +0000 From: Eric Westland Subject: Re: COZY: BURP & Dry Nitrogen I pour the entire can into my pump and have been using Phillip's excellent idea of placing a plastic bag in the top of my hardener pump container so that as the hardener empties, the bag fills the space. It's free and works well (although I have not had any 2427 problems in my climate). I see no reason why you could not just inflate a bag in the can to push out the air. -eric michael (m.j.) anderson wrote: > > I had sent an earlier email asking about MEK and BURP/dry nitrogen. > I got plenty of opinions on MEK, but nothing on the BURP or dry > nitrogen to sparge my resign and hardner cans. Does anyone do this? > I currently keep the cans in the house, for climate control, but I > would like to sparge the air/humidity out of them. > > Please let me know where do you get BURP and/or the dry nitrogen. > > Thanks, > > Michael Anderson > mikej@nortel.com > Cozy Mark IV #484 by mta bnr.ca in /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Wed, 5 Jun 1996 10:53:47 -0400 by /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Wed, 5 Jun 1996 10:53:27 -0400 by /PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/; Relayed; Wed, 5 Jun 1996 10:53:00 -0400 Date: Wed, 5 Jun 1996 10:53:00 -0400 [/PRMD=BNR/ADMD=TELECOM.CANADA/C=CA/;bcars735.b.952:05.05.96.14.53.27] From: "michael (m.j.) anderson" Subject: COZY: BURP & Dry Nitrogen I had sent an earlier email asking about MEK and BURP/dry nitrogen. I got plenty of opinions on MEK, but nothing on the BURP or dry nitrogen to sparge my resign and hardner cans. Does anyone do this? I currently keep the cans in the house, for climate control, but I would like to sparge the air/humidity out of them. Please let me know where do you get BURP and/or the dry nitrogen. Thanks, Michael Anderson mikej@nortel.com Cozy Mark IV #484 Date: Wed, 5 Jun 1996 23:59:04 -0400 (EDT) From: Bill Walsh Subject: Re: COZY: New EZ epoxy Iwill let Jeff answer the detail questions (he has more time and is more knowlegable) But seeing as my name is attached to this questionI will give only one observation.....COLOR....Imay be mistaken but I don't think that it would ba an accurate gauge. Some of my batches were considerably lighter than others and the new stuff that is being promoted is practically clear, RAE is dark, But as mine has cured it too has gotten very dark in color. And if you were referring to a possible purchase where you check the coloring of the cured parts,you would have to go to a part that hadn't been filled or painted. Don't think this matters much as a gauge for quality or strength. Thought I'd throw in 2 bits Bill W Date: Sun, 07 Jul 1996 23:19:24 -0400 From: Jim Hocut Subject: COZY: More Epoxy Woes After reading the information presented here and in the Central States newsletter about problems associated with using Hexcel 2427 in high humidity conditions I decided to take heed and switch to Safe-T-Poxy II for the time being. I'd previously done all my work in my air-conditioned shop and had no problem whatsoever with 2427, but for a while I'm going to have to rough it and work without air conditioning. I was at Aircraft Spruce East the other day to pick up some Safe-T-Poxy, and was told that the firm that bought out Hexcel's epoxy business had no interest in the homebuilt airplane market (let me guess, liability concerns?) and that production of all of the epoxies we have grown to know and love has ceased (including 2427, so the humidity concern will soon become a moot point). When I asked about Gordon Bowens' EZ-Poxy I was told that they had hardener in the warehouse, but no resin yet. Not wanting to go home empty handed, I asked for a suggestion, and was told that quite a few homebuilders were using Poly Poxy. I went ahead and bought some, figuring I'd use it for the time being on non structural layups and see what I think of it. 1) Does anyone have experience with Poly Poxy, good or bad? It claims to be a 2 phase system, so it has the potential of being pretty good stuff if their claims are true. 2) Is anyone shipping EZ Poxy yet? (Jeff Russell had offered earlier to sell us EZ Poxy from his stock - is that offer still good, and what's the co$t and delivery time?) Thanks, Jim Hocut jhocut@mindspring.com Date: Mon, 08 Jul 1996 12:52:17 From: JRaerocad@gnn.com (Jeff Russell) Subject: COZY: Epoxys Jim Hocut wrote: >1) Does anyone have experience with Poly Poxy, good or bad? It >claims to be a 2 phase system, so it has the potential of being >retty good stuff if their claims are true. We have used it quite a few times. It will also pick up some water. It is a good resin system as we have never seen any problems with the water except blush. You must remove any blush before the next layup. It also changes color when it reaches it's 2nd phase (milky white). >2) Is anyone shipping EZ Poxy yet? (Jeff Russell had offered >earlier to sell us EZ Poxy from his stock - is that offer still >good, and what's the co$t and delivery time?) It's in, and I have not been billed yet. I am looking into cans and labels but pricing should be around $65.00 for 8 lbs resin and 3.5 lbs hardener EZ10/EZ84 Gal kit AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Mon, 8 Jul 1996 09:30:13 -0400 From: william l kleb Subject: COZY: safe-t-poxy availability FYI: aircraft spruce west is carrying and has the safety-poxy clone in stock. bil Date: Mon, 08 Jul 1996 10:02:12 -0500 From: Neil Clayton Subject: COZY: 2427 and Humidity Since Nat's reference in his latest newsletter to my problem with 2427 and "humidity", the subject seems to have become settled by hearsay. I had the "bad" batch of 2427 that contained cloudy floating globs of higher viscosity than the general fluid. On the advice of a Hexcel chemist, I didn't use it, and Wicks replaced it. But...I noticed it immediately on opening the can. It wasn't exposed to Florida's humidity more than a few seconds, and then only the exposed surface area. I don't buy the 2427-humidity theory. The chemist told me the can probably wasn't topped off with inert gas in the factory. Later can's I've received also have traces of the cloudiness, but not anything like as bad. Neil From: garfield@pilgrimhouse.com (Garfield) Subject: COZY: 2427 and Humidity Date: Mon, 08 Jul 1996 17:46:15 GMT On Mon, 08 Jul 1996 10:02:12 -0500, Neil Clayton wrote: >Since Nat's reference in his latest newsletter to my problem with 2427 >and "humidity", the subject seems to have become settled by hearsay. ^^^^^^^^^^^^^^^^^^^ Whoa, wait a minute. Nat's a great guy, but I think he is the one operating on hearsay on this one. The problem is very real. I have seen it and touched it with my own eyes and hands. Nat is in Arizona. He will likely never see the problem. >But...I noticed it immediately on opening the can. It wasn't exposed to >Florida's humidity more than a few seconds, and then only the exposed >surface area. I don't buy the 2427-humidity theory. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Why do you think the chemist at the factory advised you to inert-gas burp the can whenever you closed it? Also, I remember seeing a response letter, which said they suspected that a particular lot of cans was made without filling the void with inert gas. In the case of your cloudy can, the exposure likely happened BEFORE you opened it, if the can had sat with air in the void for some time. Finally, it's not just humidity, but any oxidizing atmosphere, namely a place like California that has a lot of smog, with lots of CO, NO, ozone, and such. I was doing a wing layup in LA (world-class smog capital) California the first time I tried some 2427. It came from a can directly off the shelf of Aircraft Spruce West. I talked to Jeff Russell/Aerocad who said he had the same milky white sticky surface develop on some of his parts (N/S Carolina), and finally had to stop using 2427. These experiences should not be dismissed as mere hearsay. Rumors are a wretched thing, but this is not just a rumor. Over time the resin/hardener can be absorbing the atmospheric contaminants, and then when it really gets exposed while it is being mixed and then gets it's last grand dose when you layup the part and the wet surface sits out in the air for 4 hrs, the sticky blush may appear. When the problem appears, the surface remains tacky even several hours after the epoxy has had time to cure, so it's not some boogie-man that is going to bite you unawares, but there WAS a recent report on the net about someone discovering delam when a 2427 part was torn apart. I can only surmise that IF it was due to this "amine blush" problem, the person wasn't being very aware of the surface quality when subsequent laminations were layed up. The only way this can happen is if you 1) didn't peel-ply OR 2) didn't sand between cured layups. Whoever is building this way is asking for delams anyway. So anyone with any experience that has existing 2427 parts shouldn't be worrying, I would think. Just something to watch for if you continue to use it. And if you do get a surface that resembles this amine blush, you can confirm it by trying to remove the stuff with water. If it's poorly cured epoxy, it won't be water-soluble. The amine blush is. Garfield Date: Mon, 08 Jul 1996 19:06:06 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: 2427 and Humidity Garfield wrote: >but there WAS a recent report on the net about someone discovering >delam when a 2427 part was torn apart. I can only surmise that IF >it was due to this "amine blush" problem, the person wasn't being >very aware of the surface quality when subsequent laminations were >layed up. The only way this can happen is if you 1)didn't peel-ply >OR 2) didn't sand between cured layups. We had a case on the BerKut we were building, tape glassing on a peel plied firewall to peel-plied fuselage tub and they were sanded with 36 grit completely dull. It was in Oct. and about 65 - 70 degrees in the shop and about 80-90% humid. The 2427 was in an epoxy pump and the hardener was just starting to turn a little cloudy. A year had past and Dave Ronenberg cam to our shop to help on this airplane and tried to peel off some of the tape glass were the main spar went and it peeled off like it was on wax paper. You could see the sanding job next to the tape glass were it had not seen any new epoxy. We both scratched our head. Water in the pump? water in the glass? water as it cures? don't know, but that was the last time I used it on structural parts. A builder 20 miles from me that was using RAE and switched to 2427 was also checked for this kind of problem and guess what??? Same thing but he was not using a pump. He switch to 2410/2184 and that was the end of that. Winter was also a factor here. For us to be on the safe side, that is the only resin that I use for structural parts and airplanes. AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 910-961-2238 E-mail: JRaerocad@gnn.com Date: Tue, 9 Jul 1996 17:35:58 -0400 From: Marcnadine@aol.com Subject: 2427 Well, now after hearing all the horror stories about 2427 epoxy, does anyone want to buy a complete fuselage, canard, and main spar for $1.00 built with 100% 2427 ? Any offers? Marc Parmelee N425CZ Date: Tue, 09 Jul 1996 19:36:57 -0700 From: Mark Morris Subject: COZY: Epoxy Toxicity & Postcure 1. Are the users of MDA containing epoxies greatly concerned about the MDA risk? Is ply 9 reasonably acceptable or is everyone using multiple layers of gloves and respirators? 2. Will a cured 2427 part bond to another part acceptably using RAE or Safety-Poxy I/II? Is there any degradation caused by mixing epoxy systems? 3. I went in to this thinking postcure was an option ... but a review of this years archive of messages has me concerned. I noticed a comment that all "structural" components should be post-cured (I forget who said it). Other than the arm rests and a few such items, what isn't "structural?" Will a white aircraft in Florida need to be postcured? Mark Morris (new here; just completed CH 4.) From: Marc J. Zeitlin Subject: COZY: 2427 (fwd) Date: Wed, 10 Jul 96 8:49:07 EDT Marc Parmelee wrote: >Well, now after hearing all the horror stories about 2427 epoxy, does anyone >want to buy a complete fuselage, canard, and main spar for $1.00 built with >100% 2427 ? Well, Marc, I sure hope this is a joke. I've built 100% of my plane with 2427 also, and while I've certainly had my share of problems learning how to deal with it and have had to do a few layups over, it wouldn't even OCCUR to me to dump it. I have complete confidence that the aircraft will be structurally sound, as I make sure that I perform all my layups so that the epoxy will bond. Again, I hope you're joking. If not, I might take you up on the canard :-). Might even give you $5.00 . -- Marc J. Zeitlin Email: marcz@an.hp.com From: Marc J. Zeitlin Subject: COZY: Epoxy Toxicity & Postcure (fwd) Date: Wed, 10 Jul 96 9:01:13 EDT Mark Morris writes: >1. Are the users of MDA containing epoxies greatly concerned about the >MDA risk? Is ply 9 reasonably acceptable or is everyone using multiple >layers of gloves and respirators? Use gloves and respirators - I can't emphasize this enough. I used ply 9 (or the equivalent) for the first two years of building my Q2. I became allergic to the Safety-Poxy on my fingertips. I've been using gloves for 1-1/2 years now, and the only time I have an allergic reaction (and it's a doozy) is when I accidentally drip epoxy on my forearms during a layup and don't stop to immediately wash it off. The gloves (butyl) will protect your hands from EVERYTHING, MDA included. The carbon filter mask will protect your insides from everything. The gel will not do either. Don't take any chances - you can build perfectly well with a mask and gloves on. >2. Will a cured 2427 part bond to another part acceptably using RAE or >Safety-Poxy I/II? See below - should be "yes". >............. Is there any degradation caused by mixing epoxy >systems? Someone correct me if I'm wrong, but once the epoxy has cured, any bond to it is a structural, not chemical one. If the cured epoxy is sanded, the next epoxy should bond OK. Therefore, the answer to your question should be "no". >3. I went in to this thinking postcure was an option ... but a review of >this years archive of messages has me concerned. I noticed a comment >that all "structural" components should be post-cured (I forget who >said it). Other than the arm rests and a few such items, what isn't >"structural?" Will a white aircraft in Florida need to be postcured? While most everything is "structural", not everything is highly stressed. Definitely post-cure the wings, main spar and canard. -- Marc J. Zeitlin Email: marcz@an.hp.com From: George Graham Subject: COZY: 2427 epoxy Date: Thu, 11 Jul 1996 03:23:14 GMT Organization: AirSep Corporation Myself and many other builders, are very upset (worried ?) about the quality of this epoxy, since Jeff Russell blasted it. The day after the last Central States newsletter, I was pulling and banging away at my latest taped joints. They all appear to be as sound as any other epoxy layups. Pulled the wood off the wood parts, took pliers to start delamination on one day old layups done while it was raining outside. I wonder what gives ? Gorden Bowen, Nat Puffer, Mike Melville, Burt Rutan etc. would somebody please tell us if this stuff is garbage or not ! George Graham Modified E-Racer #206 From: RJMANC@cris.com Date: Fri, 12 Jul 1996 01:07:35 -0400 (EDT) Subject: COZY: 2427 I don't know whats up with 2427 !!! I live in a warm dry climate and have had no problems so far !! I put 2427 in my pump over a month before I used it ... (didn't do this on purpose but had some emergencies and couldn't start my layups) And I see no cloudiness or have I experienced any problems with layups.. I have my pump in a heated box to keep it at a steady tempature.. I have buit 3 of the bulkheads and numerous test projects and have noticed no problem.. I am concerned our winters are very wet and sometimes a little humid... I'm no expert but don't want to spend countless hours and dollars just to go to waste.. I would like to hear more about this any input.. My 2 cents Robert Mancuso Los Banos Ca (209)826-6814 Chapter 4 00 \______O00O0______/ | | | O 0 O #537 Date: Sat, 13 Jul 1996 03:18:52 GMT From: Neil Clayton Subject: COZY: 2427 curing I was skinning a wing the other night (great weather, no humidity) but as I put the first layer of uni on, I noticed the pump *seemed* to be putting out less than the usual stream of hardener. Thinking it was my imagination, I kept working but still had the same bad feeling about the goop the pump was putting out. The colour was wrong (or was it?) Dreading having to undo all my work if the ratio was wrong, I peel plied what I'd done and turned my attention to the pump. I took the hardener side apart and cleaned everything. I saw no blockages and nothing to cause a slower-than-usual flow. A few days later, I removed the peelply and it looks like a "normal" layup. Is it OK to just sand the surface down and do the final layers? I hate having a surface to surface joint in such a critical piece. What's the criticality of the ratio? Does it need to be exactly 44:100? Will a few percent either way effect it? And finally, is there any test I can do to check the quality of the layup? (Like the Rockwell hardness test?) Or is the only test the "keep me aloft at 10,000 feet" test? I like working with 2427, and I like the nice cosmetic finish it leaves, but I'm starting to have some serious credibility problems with it. Neil Date: Sun, 14 Jul 1996 22:18:47 -0400 From: Jim Hocut Subject: Re: COZY: 2427 curing Neil Clayton, wrote: > What's the >criticality of the ratio? Does it need to be exactly 44:100? Will a few >percent either way effect it? And finally, is there any test I can do to >check the quality of the layup? In a forum at Oshkosh last year (maybe the year before?) (seems like it was Martin Holliman's forum) it was stated that epoxy ratio is quite critical, you want to be within better than 5%. It was also stated that a good test of your epoxy is to occasionally pour some epoxy into a plastic cup and let it cure. After full cure you should be able to scratch the surface with a nail and leave behind a trace of dry residue. If the ratio is off the epoxy will be soft enough that no powder will come off when you scratch it. This very problem is why I chose not to use a pump, I purchased the postal scale from Alexander and keep different colored bicycle water bottles filled with resin and hardener. I printed a listing of resin and hardener weights for different size batches and stuck it to the wall behind where the scale resides - very quick and extremely consistent batches. Jim Hocut jhocut@mindspring.com From: "Steve Campbell" Subject: COZY: 2427 Epoxy Date: Mon, 15 Jul 1996 11:24:11 Marc J. Zeitlin writes: >It seems as though the 2427 is more sensitive to humidity, temperature, >time between layups and surface preparation than other epoxies might be. >While I have some concern with using it, I have not had any experience >that would show that ___IN MY WORKSHOP___ (Your Mileage May Vary) I >should use something else. I watch the temperature, peel ply >religiously, sand vigorously, and everything seems OK. Let me agree with what Marc says here. I am also using 2427 in my basement and had the unfortunate experience of having to remove my longerons in Chapter 5 as I had mounted them backwards and didn't discover it until the sides were completely glassed. The the glass was a real ***** to get off except in one area where it came off easily. I later realized that I had forgotten to sand and/or peel ply that area. I do both now religiously and vigorously as Marc so aptly put it. Steve Chapter 10 in progress **************************************** Stephen A. Campbell Associate Professor, EE University of Minnesota ***************************************** From: Marc J. Zeitlin Subject: Re: COZY: 2427 curing (fwd) Date: Mon, 15 Jul 96 9:08:05 EDT Jim Hocut wrote: >In a forum at Oshkosh last year (maybe the year before?) (seems like it was >Martin Holliman's forum) it was stated that epoxy ratio is quite critical, >you want to be within better than 5%. It was also stated that a good test >of your epoxy is to occasionally pour some epoxy into a plastic cup and let >it cure. After full cure you should be able to scratch the surface with a >nail and leave behind a trace of dry residue. If the ratio is off the epoxy >will be soft enough that no powder will come off when you scratch it. I had heard this same test. I have been conducting some no-so-scientific tests of the 2427 for the past few weeks, while cleaning out my pump and doing layups. Every once in a while, I'll put some resin and hardener in a cup and mix them up (knowing that the ratio isn't 44:100 - but I didn't weigh them so I don't know what it IS). No matter the ratio - too much hardener or too little - the 2427 has ALWAYS cured, and always passed the scratch test. Don't know what this proves, if anything, but it seems to be less sensitive to ratio than the directions would claim. My pump certainly puts out a ratio that cures perfectly well. WRT Neil's other question, if the surface you're concerned about sands well (basically the scratch test on a large scale) and was peel plied, then subsequent layups should adhere just fine. It seems as though the 2427 is more sensitive to humidity, temperature, time between layups and surface preparation than other epoxies might be. While I have some concern with using it, I have not had any experience that would show that ___IN MY WORKSHOP___ (Your Mileage May Vary) I should use something else. I watch the temperature, peel ply religiously, sand vigorously, and everything seems OK. -- Marc J. Zeitlin Email: marcz@an.hp.com From: ratencio@coastalnet.com Date: Wed, 17 Jul 96 08:57:26 -0400 Subject: COZY: Epoxy pumps & 2427 After reading the msg traffic on 2427 epoxy, I was a little concerned since I had used 2427 for my chpt 4 layups and had just made the upper longerons using this stuff. I did some quick comparison testing (very unscientific) and thought I'd post my findings. I decided to go do the scratch test on some left over resin from my previous epoxy work and it passed. This stuff was at a 44:100 ratio by volume. (oops!) I readjusted the pump for a 47:100 ratio and made a small batch which too passed the scratch test. Someone stated earlier that mix ratio of 2427, or epoxy resins in general, should be within 5 percent. A 44:100 ratio is a little over 6 percent on the low side. I think Marc Z. mentioned he thought 2427 was less sensitive to mix ratio than humidity. I have to concur with this statement, except that I have not seen any humidity effects on any of my layups. Here in eastern NC the humidity is typically very high, 90 percent. Maybe I've just been lucky. Either way, I plan on continuing to use the 2427 epoxy. My 2 cents ----------------------------------------------------------- Rob Atencio Cozy Mk IV #496 Chp 5 New Bern, NC E-Mail: ratencio@coastalnet.com ----------------------------------------------------------- Date: Sat, 20 Jul 1996 23:30:13 -0400 From: StetsonE@aol.com Subject: Fwd: COZY: My Peel-ply lesson (fwd) In a message dated 96-07-17 11:06:26 EDT, marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) writes: > The 2427 will NOT bond > to itself if it has started to kick (cure). The lesson here is (as Rob > says) to peel ply early, and stop a layup if the epoxy has begun to cure. > I now schedule layups this way, and everything has been fine since. I talked to a Cozy builder awhile back who said they were using 2427 when glassing the inside of the top strake covers. The layup had started to kick, but they floxed it into place on the plane anyway (their first mistake). After a full cure, they were anxious to to see if they had any leaks, so they did a pressure test of the tank before they glassed the outside of the strakes (their second mistake). They basically blew the top of the tank off..... Of course, the flox didn't bond to the interior layup of the tank top. After hearing this, I applied suction, not pressure, to my fuel tanks when checking for leaks, although Long-EZ plans say you can use either. 2427 epoxy must be funny stuff. I've never had debonding problems with Safe-T-Poxy, which is all I've used. It bonds well as long as the underlying layup is a little "green". Thankfully, my structure is done so I don't have to worry about the epoxy issue. Stet Elliott stetsone@aol.com Perpetual Long-EZ builder --------------------- Forwarded message: From: marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) Sender: owner-cozy_builders@hpwarhw.an.hp.com Reply-to: marcz@hpwarhw.an.hp.com (Marc J. Zeitlin) To: cozy_builders@hpwarhw.an.hp.com (Cozy MK-IV Builders) Date: 96-07-17 11:06:26 EDT Rob Atencio wrote: After sanding ALL the peel-plied areas, I feel confident I have good >bonding surfaces, which I wouldn't have had with the poor peel-ply job I >had done. This took more time to ensure all the loose epoxy was removed >but I did learn something in the process. I had exactly this same thing happen on my canard shear web layup. I don't think it's the peel ply's fault - we're both using 2427, and as you said, it happened on the areas we laid up FIRST. The 2427 will NOT bond to itself if it has started to kick (cure). The lesson here is (as Rob says) to peel ply early, and stop a layup if the epoxy has begun to cure. I now schedule layups this way, and everything has been fine since. -- Marc J. Zeitlin Email: marcz@an.hp.com Date: Tue, 6 Aug 1996 17:12:29 -0700 From: Sam Pavel Subject: COZY: Epoxy Greetings all, After an inspiring sojourn to OSH I am ready to jump in with all four feet. However, I have a question about the effect of epoxy resins and hardeners on plastic and rubber. To make a short problem entirely too long, I have discovered a method of measurement that is very accurate and easy. My wife (a medical lab tech) gave me these rather large syringes. I will use one for the resin and one for the hardener. Then I started wondering if there might be an adverse chemical reaction with the materials in the syringes and the materials in the epoxy. My limited knowledge in chemical reactions is no help in this problem. Thus I turn to others to garner some advice. Does my idea have merit, or am I working toward some unwanted chemical metamorphosis? Thanks in advance, Sam Sam Pavel 53230 Oakton Drive MkIV #544 South Bend, IN 46635 Have plans and built table.... (219)273-0321 email: pavel@nd.edu Date: Tue, 6 Aug 1996 21:23:28 -0400 From: SMilesCozy@aol.com Subject: Re: COZY: Epoxy Sam Pavel writes: >After an inspiring sojourn to OSH I am ready to jump in with all four feet. (snip) > My wife (a medical lab tech) gave me these rather large syringes. I will use one >for the resin and one for the hardener. (snip) > Does my idea have merit, or am I working toward some unwanted chemical >metamorphosis? The fiberglass technical counselor for our chapter, EAA 32, used this method for his lanceair 320 and the composite workshop he ran for our chapter. It looks pretty slick, although I prefer to weigh my fabric and mix my epoxy for a 50-50 epoxy to cloth ratio. I learned this at an Alexander workshop when Stan Montgomery was instructing, and it seems pretty efficient, although vacuum bagging would be better. If they're cheap, fill a couple of them up with resin and hardner and let them sit for a couple of weeks, should identify any chemical breakdowns by turning to goo :^) Good luck, Steve Miles Cozy MkIV 272 From: Marc J. Zeitlin Subject: COZY: Epoxy Allergies Date: Wed, 7 Aug 96 13:24:33 EDT People; One of the mailing list members unsubscribed recently, and I thought that I'd post the reason why for those of you who are a bit lackadaisical in your "safe epoxying" practices. >... I've been battling an allergy to epoxy for the last 4 months, and my >body has finally said no way. I've gotten to the point where just the fumes >were causing a rash (and blisters) on pretty much anything that wasn't >covered in vinyl or the fresh air breather mask. I even tried having a fan >behind me all the time and still had problems. I've been taking antihistamines >to counter the effects of the epoxy, coffee to counter the effects of the >antihistamines, and blood pressure medicine to counter the effects of both. >In short my doctor told me I was killing myself. My wife told me she would >rather live without a plane than a husband. I decided that somewhere in >chapter 10 just wasn't far enough to have someone else finish off the plane. >But you were probably just looking for the short answer. > >Thanks for all your help. The mailing list is great. This was the hardest >decision I've ever had to make even though it was pretty much made for me. Please, protect yourselves. These reactions may not show up for years (it took 2 years for me to show allergic reactions), so the fact that you haven't had any reaction _yet_ is not an indication that you won't. -- Marc J. Zeitlin Email: marcz@an.hp.com From: "Volk, Ray" Subject: Re : COZY: Epoxy Allergies Date: Thu, 8 Aug 1996 10:14:00 -0400 Marc write; >>I thought that I'd post the reason why for those of you who are a bit lackadaisical in your "safe epoxying" practices. Thanks for posting this Marc, I too had a real serious attack 6 months into my project but feel I have it under control now, 8 months later. People need to realize it's probably not "if" its "when". >I've gotten to the point where just the fumes were causing a rash (and blisters) on pretty much anything >that wasn't covered in vinyl or the fresh air breather mask. This person must have had it at least as bad or worse than I. A long sleeve shirt was not sufficient protection for me ether, I have to wrap my arms with plastic over the long sleeve shirt. I think I have previously posted what I do for protection and I now have no problems at all although at the time I had 2 months of real pain and was facing giving up the project myself. If anyone is struggling with this problem and uncertain what to do, they can contact me ether in this form or "off line" and I will be glad share my experience, i.e. what works and what doesn't. Ray Volk #426 Completed chapters 4-7, 10,11,14,19 and into 20. email rvolk@space.honeywell.com Date: Tue, 13 Aug 1996 00:02:42 -0400 From: Jim Hocut Subject: COZY: Epoxy Allergies I know we've discussed this subject to some extent in the not too distant past, but I've got a couple of questions that I don't beleive have been asked and may be of interest to more people than just myself. a) Are there any warning signs before a full blown allergy sets in? Itching after working with the offending epoxy, irration of the eyes, etc.? b) Is it the resin or hardener that causes the problem? I'd guess it's the hardener, but haven't heard a definitive answer. c) If someone develops an allergy to a particular epoxy (2427 for instance), could they switch to another system (say "Saf-T-Poxy") with little or no reaction (and take greater precautions the second time around)? Also, just a thought for someone who may be unable to work with epoxy because of allergies. I realize it's a long shot to make this work out, but in a case or two there may be another builder willing to go along. Maybe, just maybe, someone might be lucky enogh to find another builder (maybe even someone building something other than a Cozy) who's proficient at fiberglass, lives nearby, and would be willing to trade off hours spent doing layups for hours spent cutting foam, preparing for layups, SANDING, etc. (in other words anything that doesn't involve exposure to uncured resin). My 2 cents worth. Jim Hocut jhocut@mindspring.com From: Marc J. Zeitlin Subject: COZY: Epoxy Allergies (fwd) Date: Tue, 13 Aug 96 10:25:29 EDT Jim Hocut asks: >a) Are there any warning signs before a full blown allergy sets in? >Itching after working with the offending epoxy, irration of the eyes, etc.? I didn't have any reaction at all with the Safety-Poxy 14 years ago until one day - BANG!!! - my fingers swelled up and itched like mad. Others may have different stories. >b) Is it the resin or hardener that causes the problem? I'd guess it's the >hardener, but haven't heard a definitive answer. Hardener. That's got the nasties in it. >c) If someone develops an allergy to a particular epoxy (2427 for instance), >could they switch to another system (say "Saf-T-Poxy") with little or no >reaction (and take greater precautions the second time around)? I doubt it. I waited 14 years, and switched from SP to 2427 (not a huge difference, to be sure) and IMMEDIATELY had a reaction when I accidentally got some epoxy on my forearm below the gloves. Most of these laminating resins are pretty similar, so I'd bet that if you get a reaction to one, you'd have a reaction to another. Once again, gloves, long sleeves, no skin contact and masks are the requirements. -- Marc J. Zeitlin Email: marcz@an.hp.com From: stan magill Subject: COZY: Allergies to Epozy Date: Tue, 13 Aug 1996 15:54:35 +0000 Response to allergy problems with expoy systems. I had a severe reaction to Safe-T-Poxy which forced me to stop my project. I then switched to the RAE system and had no reaction at all. When RAE was not avaliable, I switched to Aeropoxy from PTM&W and still have no reaction. Your body may not be sensitive to all epoxy systems and therefore you will be able to complete your dream machine. Stan Magill SMJW@Worldnet.att.net From: stan magill Subject: COZY: Allergies to Epozy Date: Wed, 14 Aug 1996 14:59:43 +0000 Response to allergy problems with expoy systems. I had a severe reaction to Safe-T-Poxy which forced me to stop my project. I then switched to the RAE system and had no reaction at all. When RAE was not avaliable, I switched to Aeropoxy from PTM&W and still have no reaction. Your body may not be sensitive to all epoxy systems and therefore you will be able to complete your dream machine. Stan Magill SMJW@Worldnet.att.net Date: Wed, 14 Aug 1996 20:30:07 -0400 From: Jim Hocut Subject: Re: COZY: Epoxy Allergies Mark Morris wrote: > ... But I really don't believe all builders are going to these >lengths to protect themselves. Quite frankly I'm not sure I could put >in 3000 hrs dressed in armor :>). What do you think? > A friend from my EAA chapter has been using "Saf-T-Poxy" for about 2 years with disposable latex gloves, and being careful not to get it on his skin. No special ventillation precautions, and no problems so far. As for myself, I've been using 2427 (extremely low odor) for a year with the same precautions and no problems. I've also just started using Poly Epoxy, which has more odor (and therefore more organics which I will breath), and Marc's statements have scared me into at least trying out a respirator with activated carbon cartridges. So far so good. I know some medical type will probably shoot my theory all to hell, but I'm not allergic to ANYTHING (that I know about), even sat in a poison ivy patch as a kid with no ill effect, so I suspect that I have less of a chance of developing a reaction than someone who is more prone to allergies. Jim Hocut jhocut@mindspring.com Date: Thu, 15 Aug 1996 08:43:20 -0400 From: wilhelmson@scra.org Subject: Re[2]: COZY: Epoxy Allergies JIM: It is a documented medical fact(from my own and many others experience) that EPOXY allergies occur after extended exposure. It is almost like AIDS. BE CAREFUL. Date: Thu, 15 Aug 1996 09:27:00 -0400 From: william l kleb Organization: NASA Langley Research Center Subject: Re: COZY: Epoxy Allergies Jim Hocut wrote: > > So far so good. those always seem to be dangerous words as far as allergies are concerned... i think it has been mentioned before, but if you get a chance, watch the pbs show, nova, on allergies, it'll scare you into being much more cautious (that is if you want to continue building a composite plane). if nova does indeed contain unbaised science, then take heed: allergies are acquired though repeated exposure and it is only a question of when you'll have a reaction. this is the reason many people "become" allergic to more and more things as they grow older---they finally reach their tolerance for one allergen or another. > ... but I'm > not allergic to ANYTHING (that I know about), even sat > in a poison ivy patch as a kid with no ill effect. i am in the same situation, but i still wear cotton glove liners, two sets of gloves (nitrile or butyl and latex), a respirator, and a tyvex suit. i have dreamed of building a composite plane for the past ten years... WHY CHANCE IT? ---it is relatively easy to take precautions and far less expensive (both in terms of time, medical bills, and psychiatric bills ;) ) than the possible consequences. --- bill kleb (w.l.kleb@larc.nasa.gov) 72 bellanca 7gcbc 9! cz4 -> aerocanard From: Lee Devlin Subject: Re: COZY: Epoxy Pump and Epolite 2427/8 Resin Date: Thu, 15 Aug 1996 18:20:33 MDT > I have used the Ply #9 gel to protect me from the epoxy, I apply it well > up my forearms to protect the more delicate skin. As a dentist, I avoid the > use of latex gloves at home. If I develop an allergy to the gloves, then I > would have a big hassle at my office where I must wear gloves. Another option > is to apply Ply#9 gel beforeputting on gloves. I have found Ply9/disposable gloves to be ineffective in preventing me from getting a reaction to the epoxy. I am also one of those lucky individuals who had never in my life had an allergic reaction to anything. However, after about 4 months of building my plane, I got a reaction to the epoxy that came on just like flipping a light switch. My fingers swelled, turned red, and had a numbness and tingling feeling that lasted 2 weeks. The next time I made sure to use cotton liners along with the Ply9 and latex gloves, reasoning that my perspiration was disolving the water soluable Ply9 and rendering it ineffective. I got exactly the same reaction that took another 2 weeks to heal. Then I switched to butyl gloves along with disposable latex (or vinyl) over them. They have lasted for more that a year and I haven't had a reaction since I began using them. One night I needed to mix up a little flox to do a 5 minute job and reasoned that I would avoid getting any epoxy on my fingers so I just donned the vinyl gloves. To my amazement, I got a reaction even with this minimal amount of contact to the epoxy. To those graduates who have just tuned in, I have one word of advice: Butyl. Lee Devlin Date: Sat, 17 Aug 1996 13:54:56 -0400 (EDT) From: Tech Support - Rick Subject: Re: COZY: Epoxy Pump and Epolite 2427/8 Resin I had a reaction when I used ply9 and the latex gloves. However, when I switched back to straight latex gloves, or just ply9, no reaction. Proof? I had the reaction two weeks before sun 'n fun '95. I helped build four wings at sun 'n fun. Ask Jeff, he saw me there. No reaction. Even Burt cautioned against the combo of ply9 and latex. I understand why now! Rick Date: Sat, 17 Aug 1996 18:53:14 -0400 From: Jim Hocut Subject: Re: COZY: Epoxy Allergies Stet Elliot wrote: > ..... Rutan Aircraft >Factory reported in their newsletter some years ago that a few builders who >developed an allergic reaction to Safe-T-Poxy had good results by changing to >the older RAE epoxy system. It's interesting to note that the RAE was >considered at the time to be much more toxic than Safe-T-Poxy. Go figure. > I found out at OSH how Saf-T-Poxy came up with it's name (I'm thinking it was one of Burt's formus but can't recall for sure). At the time, they tested toxicity by shaving a patch of a rabbit's fur and applying an amount of the material being tested to the bare skin. A material was given a rating by how much of a reaction the rabbit's skin had. Well, they tested Saf-T-Poxy RESIN, which showed little or no reaction, hence the name. THE REST OF THE STORY is that Saf-T-Poxy HARDENER gave the bunny one hell of a rash, but nobody bothered to tell us poor builders what a nasty material it was. Also, in response to a question as to what precautions are being taken when using epoxy, I had mentioned that I was using latex gloves w/o a liner or butyl gloves etc. I neglected to mention that I change latex gloves often, I'll go through 5 or 6 pair in the course of a large layup. Again, this may not be quite as good as the other precautions, but it definitely reduces the possibility of nasty stuff getting through the latex and onto my skin. Jim Hocut jhocut@mindspring.com Date: Sat, 17 Aug 1996 20:33:31 -0700 From: "Steven D. Sharp" Subject: Re: COZY: Epoxy Allergies Jim Hocut wrote: > > Stet Elliot wrote: > > ..... Rutan Aircraft > >Factory reported in their newsletter some years ago that a few builders who > >developed an allergic reaction to Safe-T-Poxy had good results by changing to > >the older RAE epoxy system. It's interesting to note that the RAE was > >considered at the time to be much more toxic than Safe-T-Poxy. Go figure. > > > > I found out at OSH how Saf-T-Poxy came up with it's name (I'm thinking it > was one of Burt's formus but can't recall for sure). At the time, they > tested toxicity by shaving a patch of a rabbit's fur and applying an amount > of the material being tested to the bare skin. A material was given a > rating by how much of a reaction the rabbit's skin had. Well, they tested > Saf-T-Poxy RESIN, which showed little or no reaction, hence the name. THE > REST OF THE STORY is that Saf-T-Poxy HARDENER gave the bunny one hell of a > rash, but nobody bothered to tell us poor builders what a nasty material it was. > > Also, in response to a question as to what precautions are being taken when > using epoxy, I had mentioned that I was using latex gloves w/o a liner or > butyl gloves etc. I neglected to mention that I change latex gloves often, > I'll go through 5 or 6 pair in the course of a large layup. Again, this may > not be quite as good as the other precautions, but it definitely reduces the > possibility of nasty stuff getting through the latex and onto my skin. > > Jim Hocut jhocut@mindspring.comJim, Having been there, I am now using the 2427 and still itching. I had a violent reaction to the RAE epoxy several years ago. I'm talking emergency room type reaction. I immediately switch to SAF-T-POXY & SAF-T-POXY II. Still had reactions - not as severe. With the 2427 I still have skin rashes (right now for example). I get tissue reactions (sympathetic) in places where you do not desire reactions. I use butyl gloves covered w/ latex to protect the butyl ($$$$). I have use the same butyl gloves for 7 years, About time to change them out. I thought of using only latex gloves, but, latex is porous. Furthermore, I think the increase in tissue moisture inside the gloves (sweat) increases the likelyhood of a reaction. I don't have documented research on this, but past trends seem to point in this direction. All I can say is that what ever form of protection you select to use - BE CAREFUL. When I get a spot of epoxy on a area that is unprotected I immediately wipe the spot clean w/ laq. thinner. This seems to help somewhat. The vapors are also a real problem to those who have developed reactions. My 2 cents worth + a penny more - BE DAMNED CAREFUL epoxy sneaks up on you and kicks your ass when you least expect it. Steve Sharp Perpetual 3 place COZY builder - 8 years & still scratching - all over cozyiii@earthlink.net From: "Rob Cherney" Organization: Ellicott City, Maryland Date: Sun, 18 Aug 1996 10:09:09 -0400 Subject: Re: COZY: Epoxy Allergies Steve Sharp wrote: > When I get a spot of epoxy on a area that is unprotected I > immediately wipe the spot clean w/ laq. thinner. You shouldn't do this. The lacquer thinner will dilute the nasties and carry them through the skin. It's better to use a paper towel with soap and water and scrub. I have seen some people keep some of the wet baby towelettes in the shop for just this purpose. Rob- +--------------------------------------------------------+ |Robert Cherney Home Phone: (410)465-5598 | |Ellicott City, Maryland e-mail: cherney@clark.net | +--------------------------------------------------------+ Date: Sun, 18 Aug 1996 13:05:59 -0700 From: "Steven D. Sharp" Subject: Re: COZY: Epoxy Allergies Rob Cherney wrote: > > Steve Sharp wrote: > > > When I get a spot of epoxy on a area that is unprotected I > > immediately wipe the spot clean w/ laq. thinner. > > You shouldn't do this. The lacquer thinner will dilute the nasties > and carry them through the skin. It's better to use a paper towel > with soap and water and scrub. I have seen some people keep some of > the wet baby towelettes in the shop for just this purpose. > > Rob- > +--------------------------------------------------------+ > |Robert Cherney Home Phone: (410)465-5598 | > |Ellicott City, Maryland e-mail: cherney@clark.net | > +--------------------------------------------------------+Rob, Thanks for the input. However, I've been there - done that. Th problem I ran into was the area washed w/ soap/water was the epoxy seemed to smear and the result was a larger "burn". I found a paper towel saturated w/ lacq. thinner and wiping the area of the stray epoxy immediately after I detect it - folding the towel into itself after each wipe- works for me. I look for the dilution factor. I had discussed this with my dermitologist several years ago and this is what he recommended. Of course, I just made the final payment on his new ocean front beach house in the Grand Bahamas. I am at the point now where I am so allergic to epoxy Ijust live with the discomfort during the summer months. The winter months are for healing. Anyway, no matter how you protect yourself - this shit is dangerous. But, so is TNT, if handled properly it will be of great benefit. The same applies to epoxy. Enough said. Steve Sharp Scratching for 8 years cozyiii@earthlink.net Date: 20 Aug 96 01:06:57 EDT From: INFINITY Aerospace <72124.347@compuserve.com> Subject: COZY: Epoxy Allergies Hi to All, We just got back from vacation and our best Oshkosh ever. I'd like to thank the hundreds of builders who stopped by to express their support. We use a product called Derma Shield. This product comes out of the can like shaving cream, smells a little like angle food cake, and forms a barrier with and into the pores of your skin - it can not be washed off with soap and water, or any other chemical. It loughs off with your dead skin over several days from normal washing of your hands. Doctors and surgeons use this product to protect themselves from HIV / Aids in case they get a nick in their gloves. Then put Ply 9, Series 88, Invisible Gloves #1211, any other barrier cream, gloves or nothing else on your hands. We, and many others, have never had a reaction to epoxies using this product (knock on wood). If we use gloves, we first put Johnsons Baby Powder with corn starch on our hands. The corn starch seems to help absorb the sweat a little better, keeping our hands drier longer. For larger layups, we like to clean up our hands and change gloves several times. Derma Shield can be purchased from Aircraft Spruce or your local Derma Shield Dealer. Try the smallest can. You may not like it, or you may find it does not work for you. To save alot of money, become a dealer yourself if the product works for you. HTH. Infinity's Forever, EAA Member EAA Technical Counselor JD EAA Flight Advisor AOPA Member Test Pilot James D. Newman, President LCDR F-14 USNR INFINITY Aerospace P. O. Box 12275 El Cajon, CA 92022 (619) 448-5103 PH & FAX 72124.347@compuserve.com Home Page http://ourworld.compuserve.com/homepages/INFINITY_Aerospace Date: Tue, 20 Aug 1996 10:44:56 -0400 From: HighPlane@aol.com Subject: Re: COZY: Epoxy Allergies--vinyl gloves I'm using vinyl gloves, rather than latex, because I read somewhere (I THINK) that they're less porous than latex. I get them at Sam's; seems like they're about $7 or so for 120. No epoxy reaction yet--but then again, my exposures are, alas, fairly infrequent at the moment ... id <01I8S1GAURSG8ZPN6D@InfoAve.Net> for cozy_builders@hpwarhw.an.hp.com; Tue, 27 Aug 1996 17:30:24 -0400 (EDT) Date: Tue, 27 Aug 1996 17:30:24 -0400 (EDT) Date-Warning: Date header was inserted by InfoAve.Net From: Nick Ugolini Subject: COZY: Epoxy Can anyone give me a clear idea of what is the epoxy de jour (of the day, or hour). and where I can purchase it at.... I need to do some glass work on my plane, and it has been a long since I have purchased any supplies. Nick Ugolini unick@mail.charleston.net Varieze N89RS Date: Sun, 01 Sep 1996 10:01:54 -0400 From: "Douglas O. Powell" Subject: COZY: Epoxy - Aeropoxy Reformulated While at Oshkosh, I stopped at the PTM&W booth. The rep said that Aeropoxy PR2032/PH3665 had been recenty reformulated to reduce sensitivity to "amine blush" and also reduce the viscosity. PH3665 is the slowest of the three hardeners (2 hr pot life) used with the PR2032 resin (PH3417 has 15-20 min pot life, and PH3660 has 1 hr). Forgot to ask just when this reformulation occurred. 1) Has anyone used both the old and the new versions, and if so, how do the humidity sensitivity and viscosity/wet-out behavior compare? 2) Can anyone compare the new Aeropoxy vs Hexcel 2427? Thanks, Doug Powell Cozy MK-IV #293 powelldo@ix.netcom.com Date: Sun, 01 Sep 1996 14:26:41 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Epoxy - Aeropoxy Reformulated Douglas O. Powell Wrote >1) Has anyone used both the old and the new versions, and if so, >how do the humidity sensitivity and viscosity/wet-out behavior >compare? I have used both new and old. The old left in a pump started to show clowdy in both the resin and hardener almost at once. The new stuff only the resin showed water first and then the hardener about a month later??? The parts we made out of both new and old were not vary stable after a 7 day cure (creep) after post cure we only found a 160 MAX Tg after a post cure of 190 degree and a slow ramp check after cooled NOT GOOD >2) Can anyone compare the new Aeropoxy vs Hexcel 2427? Blush and peel strenght was a issue for us because of humidity. I don't think I would use in fuel tanks. ??? Tg of 2427 was about 210 degrees from our test AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com http://www.windev.com/aerocanard Date: Tue, 03 Sep 1996 18:59:08 From: JRaerocad@gnn.com (Jeff Russell) Subject: Re: COZY: Epoxy Testing Nick Ugolini wrote: >What is the procedure for testing epoxy resin? mix up some and let full cure. scrach test with a nail and if it scraches white??? it OK AeroCad Inc. Jeff Russell 1445 Crater Lane Yadkinville, NC. 27055 phone/fax 910-961-2238 E-mail: JRaerocad@gnn.com http://www.windev.com/aerocanard by InfoAve.Net (PMDF V5.0-6 #4800) id <01I91UOGPRHS8XRYPP@InfoAve.Net> for cozy_builders@hpwarhw.an.hp.com; Tue, 03 Sep 1996 18:04:05 -0400 (EDT) Date: Tue, 03 Sep 1996 18:04:06 -0400 (EDT) Date-Warning: Date header was inserted by InfoAve.Net From: Nick Ugolini Subject: COZY: Epoxy Testing I have some old epoxy (about 3 years old) BUT the cans and seals have never been opened. Some of the epoxy opened 6 months ago (used to repair my Snapper lawn mower) appears to be working just fine. I plane to use for non-structual uses, ie filling, surface layups........ What is the procedure for testing epoxy resin? Nick Ugolini unick@mail.charleston.net Varieze N89RS Date: Tue, 17 Sep 1996 07:27:54 -0400 (EDT) From: "George A. Graham" Subject: COZY: 2427 Epoxy Great news ! I talked with Gorden Bowen last night. He is away from his computer, hasn't seen email in over 4 mo. Hopes to get home in October. He said that the 2427 epoxy showed zero gain/loss in fuel, both aviation and auto during testing, same as STP and RAE. The resin is basically the same for all three, the hardner is slightly different, but the cured properties are almost identical. The complaints about 2427, center around it not being as forgiving as STP and RAE, as to high temps/humidity, and high C02 in the shop. A waxy film builds on partially cured layups, and in the hardner pump during the above conditions. Otherwise, it's as good as the others. This conversation was a great relief to me. Modified E-Racer #206 Strakes and Mazda Engine next George Graham {ca266@freenet.buffalo.edu} From: "Krasa, Paul" Subject: RE: COZY: 2427 Epoxy Date: Tue, 17 Sep 1996 09:37:04 -0400 Larry Schuler said: > > Maybe all epoxys have their traits, 2427 is the only one I have >worked > with so far. Glad to share the experience. All the epoxy resin systems that we are working with will exhibit this trait to some extent. I believe that it is caused by the exothermic chemical bonding which takes place in the epoxy/resin systems that we use. As the reaction takes place over time there are less unlinked chemical chains that can be formed. If this is true, then if fresh epoxy is placed on top of epoxy that has stared to set up there are fewer unlinked chemical chains for the new epoxy to link with thus the interface between the older layup and the new layup will be weak. In other words, the inner laminar shear strength of the two layers will be lower due to the lack of unbounded chemical chains. This would explain why Mark's layup came apart. This is probably only worth about a half a penny, but I hope it will sheds some light on the subject, and does not muddy the waters. Paul Krasa Long EZ 214LP !---*---! Project Status: Wing roots are fiberglassed to the strakes, and I'm just about finished sanding the underside of the wing. This week I will cut the wings back off. Next week, I will install the electric trim system for pitch and roll. 95% done 50% to go. An experimental airplane is never done. > Date: Tue, 17 Sep 96 11:27:26 est From: "Larry Schuler" Subject: COZY: 2427 Epoxy George Graham wrote: >I talked with Gorden Bowen last night. He is away from his computer, >hasn't seen email in over 4 mo. Hopes to get home in October. >He said that the 2427 epoxy showed zero gain/loss in fuel, both >aviation and auto during testing, same as STP and RAE. >The resin is basically the same for all three, the hardner is slightly >different, but the cured properties are almost identical. >The complaints about 2427, center around it not being as forgiving as >STP and RAE, as to high temps/humidity, and high C02 in the shop. >A waxy film builds on partially cured layups, and in the hardner pump >during the above conditions. FWW: I have noticed the film, but only when I do a layup when the humidity is generally over 60 to 70 % in my shop. I avoid the need to sand this off by always using peel ply..... the thin gummy layer is pulled right off with the peel ply. Light sanding is usually all I need to do. Aslo, as Marc has mentioned in the past, can't put fresh epoxy over a layer that has started to set (usually in an hour to 1-1/2 hour depending on temp {this is WELL before the gel stage}). Maybe all epoxys have their traits, 2427 is the only one I have worked with so far. Glad to share the experience. Did Gordon say anything about alcohol or other additives in auto gas? Larry Schuler MKIV-#500 Chap.6 Date: Tue, 17 Sep 1996 22:21:00 -0400 From: SBLANKDDS@aol.com Subject: COZY: COZY - 2427/2428 resin in florida My .02 on resin I started with safe-t-poxy II, it worked well, smelled like I was building something... I switched to 2427/2428 when I started the canard and noticed the hardner container of my pump seemed to separate and require mixing. I have no idea what this separation meant, but I did not want to build an entire plane and then change resins!!! Also it is harder to see the layups as you go, hard to see if it is wetted out well. It is almost clear in color. I bumped my right elevator tip when moving my canard wing before I floxed the end of the elevator. The outer 5" of the underside delaminated quite easily and came off the foam. None of my older safe-t-poxy layers can be peeled at all. The layups looked good. When doing my repair I was able to separate the layers of glass further from the damaged area. This separated easier than I feel comfortable. I will finish the repair and flox the ends, but the canard will be checked often for any signs of delamination when finished. I am considering scraping the canard....to be determined. With our 80-100% humidity, don't use the 2427 resin. I'm back to the EZ 10 (safe-t-poxy) like stuff. This can be purchased from Jeff Russell at Aerocanard. Most recent Price =$130 / 2 gallons + shipping. E-Mail Jeff at: jraerocanard@gnn.com Steve Blank Cozy Mark IV #36 Attaching canard, cutting winglets, having fun! Date: Wed, 18 Sep 1996 23:51:28 -0500 From: Neil Clayton Subject: COZY: 2427; change of manufacturer I ordered two galls of 2427 and it came under the label; "H B FULLER" as the manufacturer, not "Hexcel". Anyone know why the change? What about mixing the new stuff with the old? Thx Neil From: "Steve Campbell" Subject: RE: COZY: 2427; change of manufacturer Date: Thu, 19 Sep 1996 07:47:05 On Wed, 18 Sep 1996 23:51:28 -0500, harvey3@worldnet.att.net wrote... >I ordered two galls of 2427 and it came under the >label; "H B FULLER" as the manufacturer, not "Hexcel". > >Anyone know why the change? >What about mixing the new stuff with the old? > >Thx >Neil > H. B. Fuller bought out that division of Hexcel a few months ago. It's the same stuff from the same people, just a new name. Steve Campbell **************************************** Stephen A. Campbell Associate Professor, EE University of Minnesota ***************************************** Date: Sun, 13 Oct 1996 08:03:53 -0400 (EDT) From: "George A. Graham" Subject: COZY: Fuel & 2427 Epoxy Does anyone know who has the epoxy samples soaking in fuel ? As you might know, my strakes are completed with the 2427. Thanks in advance. George Graham Modified E-Racer # 206 Mazda Engine Installation (716) 874-3277 Date: Mon, 14 Oct 1996 11:11:37 -0400 From: AlWick@aol.com Subject: Re: COZY: Fuel & 2427 Epoxy I've been soaking some foam and 2427 in gas for about 6 months now. 2 months ago I changed fuel in jar to stuff with alcohal (sp), no effect. The only way I know it has alcohal is that the fuel destroyed my gaskets in weed trimmer. -al Date: Tue, 15 Oct 1996 09:10:18 -0400 From: AlWick@aol.com Subject: COZY: Fuel & 2427 Epoxy My fuel testing totally subjective. Just put some gas in mason jar, threw in piece of strake foam and section of glass/epoxy layers. Put lid on it and let it sit for few months. To date no visible signs of degeneration, layer seperating, etc. I did this when I saw an ultralight fuel tank totally eaten away by the new fuel. The sealer was just a bunch of goo that plugged inlet. Resin was eaten out of first couple glass layers. -al Date: Tue, 15 Oct 1996 12:11:32 -0700 From: Chris van Hoof Organization: C van Hoof - Architect Subject: COZY: Epoxy Hi, This Cozy builder would like to get hold of some spec to the Epolite 2427 I am presently using another System by Hexcel called Epolam 2022 Spec and description as follows:- EPOLAM 2022 Epoxy laminating system - High performance Tg 100C. PHYSICAL PROPERTIES Resin Hardener Mixing ratio by weight 100 40 Mixing ratio by volume 100 50 Aspect:liquid Colourless Colourless Brookfield viscosity at 25C 1600+-200mPa.s 40+-5mPa.s Specific gravity at 25C 1,17+-0,02 0,94+-0,02 Mixing viscosity at 25C 600+-100mPa.s Mixing specific gravity at 25C 1,10+-0,02 Pot-life (280 g) at 25C 1 h 05 min +- 5min MECHANICAL AND HEAT RESISTANCE PROPERTIES Final hardness* ISO 868 Shore D 85+-2 Tg (DSC)* C 100 Flexural Strenght* ISO 178 MPa 125+-10 Flexural modulus of elasticity* ISO 178 MPa 3400+-200 Tensile strength* ISO 527 MPa 58+-5 Demoulding time at room temp h 24-36 Complete hardening time at room temp d 7 N B These values were determined on pure resin (without any fillers or fabric) * The above properties obtained with standardized specimens and in precise chemical crosslinking conditions correspond to optimum values of the system after complete hardening. Note from the Cozybuilder #219 - All the above info copied as to the best of my reading and typing skills, and same info is available in hardcopy form by asking Hexcel France/ Hexcel GmbH / Hexcel Espana and Hexcel Italia ( more info if you request same from me) Another Cozy builder in a the Durban area, found that the hot temperatures in his area shortened the potlife and changed to the "sister"system Epolam 2023 - this has a potlife on the above info of over 3 hrs. Please help us obtain similar info to the Epolite 2427. Thanx. Chris #219 with Cozy into chapter 8 cvh@iafrica.com Date: Thu, 17 Oct 1996 14:02:19 -0400 From: DFinn7971@aol.com Subject: COZY: Ratio Changes for Epoxy Pump Hello everyone! Jim Rios, my Cozy Classic buddy, is planning to switch from Safety Poxy to an as yet unnamed brand. I gave him the archives relating to the pro's and con's of the various choices. He asked that I post a note requesting a description of how the ratio pump (he has the sticky stuff dispensor) would have to be modified to accomodate each of the various chaoices. My memory is that you need to change the pivot point but I don't know how. Could anyone who has the specifics for the various epoxies please publish them. Thanks, Dick Finn Cozy Mark IV #46 DFINN7971@AOL.COM Date: Mon, 21 Oct 96 21:27:10 -0800 From: Eric_Westland@msvl.wednet.edu (Eric Westland) Organization: Marysville School Dist. Subject: COZY: 2427/Fuel/Crash I know we have had several discussions about the use of 2427 and most recently, a short dialog on 2427 and fuel compatability. What causes me to bring this up again is a Central States Association Newsletter article contributed by Valerie Harris, wife (?) of Robert whose Cozy was destroyed. It is quite short and the author asks that this be passed on, so copyright issues are probably not a concern. During a flight test, the engine stopped which resulted in the crash. They go on to say, " We had a lab in Boston test samples from the strakes and found the 100LL fuel in the tanks started to disolve the 2427 resin and flox causing small flakes. These went through the tank screens and were caught in the gascolator which has a finer filter. The gascolator had been checked 5 hours earlier. We had the lab run the same tests using RAE and the Safe-T-Poxy Resins. There were no problems with these resins. Please pass on again the warning about Epolite 2427 Resin". Here in the low humidity Pacific Northwest, I have had good luck with 2427. My strakes are complete, leak tested and ready to finish. I don't want to have to do them over, but the picture they sent along is very sobering. I will if there are unanswered questions. Is there an issue here? I would guess I am not the only one to reach this point with the 2427, what have others discovered? Could the lab in Boston be jumping to the wrong conclusion? This accident was news to me, do others know any additional details? Sleepless in Seattle, Eric -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Sent via ExpressNet/SMTP(tm), Internet Gateway of the Gods! ExpressNet/SMTP (c)1994-95 Delphic Software, Inc. -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- Date: Tue, 22 Oct 1996 09:27:11 -0400 From: DFinn7971@aol.com Subject: Re: COZY: 2427/Fuel/Crash In a message dated 96-10-22 03:22:26 EDT, Eric_Westland@msvl.wednet.edu (Eric Westland) writes: << We had a lab in Boston test samples from the strakes and found the 100LL fuel in the tanks started to disolve the 2427 resin and flox causing small flakes >> Ovewr the past few years I've occasionally wondered about the use of fuel cells. Alternatively, bonding the fuel cell material to the inside of the tanks with some type of adhesive. I'll be building my strakes in the not too far distant future and wonder if this idea has been tried. Dick Finn Cozy Mark IV #46 DFINN7971@AOL.COM From: Marc J. Zeitlin Subject: COZY: 2427/Fuel/Crash (fwd) Date: Tue, 22 Oct 96 11:08:11 EDT Eric Westland quoted: >.......... " We had a lab in Boston test samples from the strakes and found >the 100LL fuel in the tanks started to disolve the 2427 resin and flox causing >small flakes. These went through the tank screens and were caught in the >gascolator which has a finer filter. The gascolator had been checked 5 hours >earlier. We had the lab run the same tests using RAE and the Safe-T-Poxy >Resins. There were no problems with these resins. Please pass on again the >warning about Epolite 2427 Resin". >Is there an issue here? I would guess I am not the only one to reach this >point with the 2427, what have others discovered? Well, a few people have had samples of 2427 sitting in gas for a while, and have not seen any degradation, even after months