From: Chm12345 Date: Sat, 16 May 1998 23:41:11 EDT Subject: COZY: Epoxy pump recommendations Dear Cozy friends, I have finally started working on the education chapter of my MKIV and I would like to buy an epoxy pump. Since you guys have a lot more experience than me regarding the different units avalible in the market, I would like to get your opinions into which should I buy. I'm using the Martin Scheufler L285 epoxy which mixes 100:50 by volume. I was recommended the "Sticky-Stuff" dispenser from Michael Engineering but I noticed it doesn't come in the ratio I need (I have to admit I haven't called to check, I say this is just form seeing the catalog options). I could buy an adjustable ratio unit but here is were I could use your opinion. Wich is best, the "Sticky-Stuff" or the AR-100?. Regarding the use of L285 epoxy, I don't have experience with the others (this is my first composite project), but I found it quite nice to work with. The ability to adjust the working time is a nice feature and it has a beautiful transparent blue color when mixed. It also seems to be very thin. I noticed today this product cleans incredibly easy with soap (you can smell it react with soap), I don't know if other epoxies do this but I have never seen something like it before. Thanks, Chris Martin "with still BUNCH to learn new builder" :) Date: Sun, 17 May 1998 07:20:02 -0400 (EDT) From: "George A. Graham" Subject: Re: COZY: Epoxy pump recommendations On Sat, 16 May 1998, Chm12345 wrote: I would like to get your > opinions into which should I buy. > Chris Martin For less than $ 20 you can purchase two sets of West System "mustard" type pumps. The ratio is adjustable by trimming the stroke limiter inside the hardner pump. You can modify the can lid of any epoxy to accept the pumps. The only drawback I've seen, is keeping track of the squirts of each, so we devised a "Do not talk to the mixer when pumping!" rule. If you do lose track, throw out that cupful. Cheap, light, and functional. To anticipate your next question, I used a heating pad to warm the epoxy which was sitting in a bucket with a rag draped over to keep in the heat, and out the dirt. I'm talking the type of heating pad that you put under your aching back after the annual tennis match. George Graham ca266@freenet.buffalo.edu (716) 874-3277 Modified Eracer - Mazda Powered From: Fritzx2 Date: Tue, 19 May 1998 10:41:46 EDT Subject: Re: COZY: Epoxy pump recommendations Chris Martin writes, >I have finally started working on the education chapter of my MKIV and I would >like to buy an epoxy pump. Hi Chris, The Cozy group has talked about measuring epoxy before and there doesn't seem to be a general consensus. There are those that wouldn't spend a nickel towards a pump when they feel the ratio balance is quite adequate while there are others who wouldn't give up their pump if you paid them to do so. Check in the archives for a full discussion. I would be cautious about any method that does not have a demonstrated ratio error of, from what I've been told, of less than 5 %. Personally I like to keep it below that, say no more than 2 %. Fortunately, I have access to an accurate scale from work to verify my method. No matter what method you use, I would somehow verify it is correct before making any plane parts, (or fancy onces for that matter) :). >From experience I can tell you that a balance you can build or the J & B built AR 100 can be calibrated to less than 2 % ratio error and the measurement is very consistant. The AR 100 can easily be set from 100:1 to 100:100, hence the AR for adjustable ratio. I think the Sticky-Stuff dispenser is not easily adjustable. I think you have to drill extra holes in the pivot arm to adjust the ratio. >I'm using the Martin Scheufler L285 epoxy which mixes 100:50 by volume. The AR-100 operates over a certain viscosity range. Since you are using this for hand layup I would assume that the Martin Scheufler L285 epoxy resin and hardener have a similar viscosity at an operating temp. of 75 F as the EZ Poxy or old Safe -T- Poxy. I can check the AR -100 product literature if you want the operating viscosity range. John Fritz fritzx2@aol.com From: Chm12345 Date: Tue, 19 May 1998 22:30:57 EDT Subject: Re: COZY: Epoxy pump recommendations Thanks for your reply John (and others), I would appreciate if you can give me the AR-100 viscosity range. The viscosity for the L285 resin is 600-900 cps @ 77 F and 60-100 cps @ 77 F. Have you ever heard anything about the "Proportionator MTB Junior" unit sold by Aircraft Spruce?. It is about twice the cost of the other dispensers but if there is truly something really special about it I don't mind paying extra for the peace of mind of having an accurate epoxy mix. Chris Martin Date: Mon, 17 Aug 1998 07:20:54 -0700 Subject: Re: COZY: The cheapest epoxy pump From: alwick@juno.com (ok How) Great idea Lee. I used essentially same approach, but found that ratio would change unexpectedly. To solve this, I placed pumps above my level balance described in plans. Then pump into cups resting on balance. This provides a double check of ratio w/o significant waist of time. I was quite pleased and it saves $200+ . -al wick 83% comp. Cozy MkIV sn 389 with stock Subaru 2.5 engine. Computerized cockpit. Done building components, now installing winglets. Expect completion date 4-30-99. On Mon, 17 Aug 1998 02:08:07 EDT Lee810@aol.com writes: >I was looking at the West epoxy pumps recently and concluded it would be easy >to modify them to virtually any ratio. I bought some of the MGS L285 epoxy >and needed a 100:50 volume ratio. I could have modified my Michael >Engineering pump by making a new handle for it, but didn't want to have to >clean it (ever!) when I need to switch ratios or epoxies again. > >The West pumps will only screw on to the West cans, but I made up a little >fixture out of 1x6 scrap pine that looks like a little bench and put two Hefty >1/2 gallon freezer containers under it. I then made two 1" diameter holes >through it as well as the lids on the plastic containers through which I >placed the pumps. Then I shortened the spacer in the hardener pump to limit >it to half stroke (instead of 1/5 stroke) which was pretty easy. You could >also modify it for 100:45 or anything less than 100:20 for that matter. > >You must make sure that the pumps are properly primed and once that's done, >it's as easy to use as my $225 Michael pump. And it only cost $11 for the >pumps and containers. Best of all, I will never have to clean it because I'll >just replace the containers and pumps when it gets cruddy. > >Lee Devlin LongEZ N36MX Cozy IV under construction >http://members.aol.com/lee810 > _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] From: "Vernon Asper" Subject: COZY: Re: [canard-aviators] The cheapest epoxy pump Date: Mon, 17 Aug 1998 09:33:39 -0500 I've been using the "new" MGS epoxy in my Michael Engineering pump but there is a huge problem with this. The resevoirs in this pump are made of plastic which, unfortunately, is pervious to the hardener. If you leave the hardener in one of these, the volatile portions will escape throught the plastic, causing the remaining resin to start to crystalize and eventually to dry up. I thought at first that it was "normal" crystallization from letting it get too cool and tried to re-dissolve the crystals using heat, but that was only part of the problem. When I left a relatively small amount of hardener in the resevoir and went to refill it recently, it was entirely crystallized, requiring me to clean the pump again. This is also a problem at the outlet of the pump, where crystals will form from the same phenomenon and clog the tube. In short, I cannot recommend using the MGS in this pump for these reasons but had no alternative until now. Lee,If you are willing to do so, could you make a set of these pumps for me? I'd be happy to pay for the shipping or whatever and it would be worth the extra cost to have someone who has been through it, make a set for my use. I don't think crystallization would be a problem with this setup because you'd retain the original steel cans which are impervious to the volatiles in the resin. Anyone else had this problem? Vernon Asper 228-688-3178 or Professor of Marine Science 228-872-4261 University of Southern Mississippi FAX 228-688-1121 Institute of Marine Sciences Email Vernon.Asper@usm.edu Building 1103 Room 102 Stennis Space Center, MS 39529 -----Original Message----- From: Lee810@aol.com To: cozy_builders@canard.com ; canard-aviators@canard.com Date: Monday, August 17, 1998 8:27 AM Subject: [canard-aviators] The cheapest epoxy pump >[The Canard Aviators's Mailing list] > >I was looking at the West epoxy pumps recently and concluded it would be >easy to modify them to virtually any ratio. I bought some of the MGS >L285 epoxy and needed a 100:50 volume ratio. I could have modified my >Michael Engineering pump by making a new handle for it, but didn't want >to have to clean it (ever!) when I need to switch ratios or epoxies >again. > >The West pumps will only screw on to the West cans, but I made up a >little fixture out of 1x6 scrap pine that looks like a little bench and >put two Hefty ½ gallon freezer containers under it. I then made two 1" >diameter holes through it as well as the lids on the plastic containers >through which I placed the pumps. Then I shortened the spacer in the >hardener pump to limit it to half stroke (instead of 1/5 stroke) which >was pretty easy. You could also modify it for 100:45 or anything less >than 100:20 for that matter. > >You must make sure that the pumps are properly primed and once that's >done, it's as easy to use as my $225 Michael pump. And it only cost $11 >for the pumps and containers. Best of all, I will never have to clean >it because I'll just replace the containers and pumps when it gets >cruddy. > >Lee Devlin LongEZ N36MX Cozy IV under construction >http://members.aol.com/lee810 > >---------------------------------------------------------------------- >For details on sponsors of this list, copyrights, and how to remove >yourself from this list, please visit: > >http://www.canard.com/ca-ending.html > >(c) 1997,1998 Canard Aviators. support@canard.com >---------------------------------------------------------------------- > From: Epplin John A Subject: RE: COZY: Re: [canard-aviators] The cheapest epoxy pump Date: Mon, 17 Aug 1998 10:17:42 -0500 > -----Original Message----- > From: Vernon Asper [SMTP:vernon.asper@usm.edu] > I've been using the "new" MGS epoxy in my Michael Engineering pump but > there > is a huge problem with this. The resevoirs in this pump are made of > plastic > which, unfortunately, is pervious to the hardener. If you leave the > hardener in one of these, the volatile portions will escape throught the > plastic, causing the remaining resin to start to crystalize and eventually > to dry up. [Epplin John A] I have been using "Jug pumps" from Grainger since the start of my project. I use a small wormgear clamp on the hardener pump to limit its travel. This is adjustable and can be set for any system. The pump screws onto the jug that MGS is shipped in, no problem. However the hardener presents a bit of a problem. I used a metal screw top can, quart size, and cut the lid out so the disassembled jug pump could be assembled through the lid. Each batch is also weighed, the pumps provide a starting point which makes weighing fast and easy, using an electronic scale. I have noticed the problem Vernon points out with MGS. Blue crystals form on the pump outlet if they are not used for several days. At first I thought humidity may be an influence but am not convinced it really is. I have been cleaning these off with tooth pick, Q-tip etc, and discarding the stuff. Don't think it is a problem, just a nuisance. Just lucky I found a metal can when I was looking for a container for the hardener. John Epplin Cozy Mk4 #467 From: LEE_L_DEVLIN@HP-Greeley-om2.om.hp.com Date: Mon, 17 Aug 1998 09:35:16 -0600 Subject: COZY: Using MGS epoxy with pumps Vernon wrote: <> This will be truly heart-breaking if there is no work around for it. I'm not sure my approach would rectify this problem as I am using plastic (HDPE) freezer containers for both the resin and hardener. I made the hole in top of the containers undersized so the pumps are a press fit, but I also put a razor slit in each lid to allow air to replace the epoxy as the level goes down. This could be improved upon with Phil Johnson's approach of using a plastic baggy to fill the volume above the epoxy. However, if the problem is that the volatiles are escaping through the molecular structure of the plastic, then that's another problem entirely. The primary cause of crystallization in other epoxy hardeners was determined to be from reaction with CO2 in the atmosphere. It has been shown that if you can seal up the containers well enough or use a purge gas of nitrogen, this effect can be eliminated. I'll keep an eye on my hardener container and see if it begins to crystallize. If so, it may be necessary to replace it with a metal container. I know an empty metal West container would work. Lee Devlin LongEZ N36MX Cozy MKIV under construction http://members.aol.com/lee810 From: "Hunter GA (Gary) at MSXSCC" Subject: RE: COZY: The cheapest epoxy pump Date: Mon, 17 Aug 1998 12:02:20 -0500 In my opinion, epoxy ratio pumps and dispenser tops for resin jugs are not practical for the homebuilding environment. The epoxy ratio pumps are swell pieces of machinery that work well when used frequently and well maintained. However, when you combine the inherent characteristics of the resins and curing agents with the infrequency of use typically seen in most homebuilders garages, you are bound to have problems each time you go to use it. The resin frequently crystallizes and plugs the lines or fowls the check valves, etc. The curing agents are corrosive (to varying degrees) and damage the metallurgy and/or plastics. This can and does effect the pumps ability to dispense accurate ratios. Much of this goes on without any visual clues. All this gives me the willies to think y'all believe you have something reliable and accurate. And now that I keep hearing about y'all changing from one resin system to another. WOE !! The plastics and metals in these pumps are sometimes tailored to specific resins and more importantly the curing agent. You change out the curing agent and it might corrode the check valves and pump seals. Next thing you know your ratio is off. IF, and I mean big IF, you catch it, it takes a half a day of building time to clean and fix the pump. Two months later, it does it again. Is it really worth it to have the luxury to push a lever and squirt resin in a cup ? Again, this is my professional opinion - this is no place to be complacent. I am not knocking Michael Engineering - I recommend their equipment to my customers all the time. However, these are industrial environments that use the equipment daily. For the homebuilder's environment, I favor a "Good" digital scale and a 2 bit calculator over dispenser pumps. No matter what resin system you are using, you can depend on it being as accurate as you are - anytime. I encourage each of you to take a look at the scales available at http://www.balances.com/index.html Through these folks, you can buy a Ohaus LS2000 that will weigh up to 2000 grams in 1 gram increments for ONLY $83.00 - OR, the ACCULAB V-4000 that weighs 4000 grams in 1 gram increments - ON SALE for $119. These are both AC/DC (9V) , and very portable. I do not recommend the Pelouze scale being sold through Aircraft Spruce or Wicks as it only weighs in 2 gram increments. Nor would, I fool around trying to obtain something from the Office Supply stores either. Unless things have changed, I found they generally don't have the capacity or the accuracy. Ohaus and Acculab are laboratory quality equipment. Once you have a scale like this, you can use it for a myriad of things. Weighing parts you built or lightened, balancing your engine components, etc. They are very handy. Practically no maintenance at all. Just keep it clean. If you change resins mid-stream, it works the same way no matter the mix ratio. Keeping a little cheapy 2 bit digital calculator close to the balance will allow you to calculate the exact curing agent amount. Tare the balance and add the curing agent directly to the cup with the resin in it. No transferring - No waste. The calculator will get all gunked up after awhile - so chunk it, get another one and go on. I have never had a bad batch of resin resulting from the equipment. Nor have I ever wondered if I did while cruising at 10,000 ft. KINDEST REGARDS, Gary Hunter Technical Service Representative EPOXY RESINS TECHNICAL INQUIRY SHELL CHEMICALS, USA e-Mail - gahunter@shellus.com > -----Original Message----- > From: Lee810@aol.com [SMTP:Lee810@aol.com] > > I was looking at the West epoxy pumps recently and concluded it would be > easy > to modify them to virtually any ratio. I bought some of the MGS L285 > epoxy > and needed a 100:50 volume ratio. I could have modified my Michael > Engineering pump by making a new handle for it, but didn't want to have to > clean it (ever!) when I need to switch ratios or epoxies again. > > The West pumps will only screw on to the West cans, but I made up a > little > fixture out of 1x6 scrap pine that looks like a little bench and put two > Hefty > 1/2 gallon freezer containers under it. I then made two 1" diameter holes > through it as well as the lids on the plastic containers through which I > placed the pumps. Then I shortened the spacer in the hardener pump to > limit > it to half stroke (instead of 1/5 stroke) which was pretty easy. You > could > also modify it for 100:45 or anything less than 100:20 for that matter. > > You must make sure that the pumps are properly primed and once that's > done, > it's as easy to use as my $225 Michael pump. And it only cost $11 for > the > pumps and containers. Best of all, I will never have to clean it because > I'll > just replace the containers and pumps when it gets cruddy. > From: Fritzx2@aol.com Date: Mon, 17 Aug 1998 14:36:17 EDT Subject: COZY: Air tight epoxy pump Vernon Asper wrote: >I've been using the "new" MGS epoxy in my Michael Engineering >pump but there is a huge problem with this. The resevoirs in >this pump are made of plastic which, unfortunately, is pervious >to the hardener... >If you leave the hardener in one of these, the volatile portions >will escape throught the plastic, causing the remaining resin to >start to crystalize and eventually to dry up. I agree plus moisture will get in which is not good. On my J & B pump, and maybe on your pump also, there is a hole in the lid to allow air to replace the metered out epoxy resin or hardener. I made an air tight reservoir replacement from the cans that the epoxy is shipped in. You can take a look at my approach on the web at: http://members.aol.com/Fritzx2/epoxy_pump.html Not mentioned in the text of my web page, I plug the exit tubes when the pump is not in use. If anyone wants a copy of the page without the pictures because they only have email and no web access, send me a message and I'd be glad to send you the text and the pictures zipped (that is if you can receive attached files). Let me know what you want. One other guy before me did a similar can conversion plus he added a inert gas blanket system to boot. John Fritz fritzx2@aol.com From: Fritzx2@aol.com Date: Mon, 17 Aug 1998 16:22:14 EDT Subject: RE: COZY: The cheapest epoxy pump Gary Hunter wrote: >The curing agents are corrosive (to varying degrees) and >damage the metallurgy and/or plastics. This can and does >effect the pumps ability to dispense accurate ratios. >Much of this goes on without any visual clues. This also gave me reason for concern. For this reason, I have calibrated my J & B pump over 20 times during the last 5 - 6 months of use since I first put it into service (brand new) back in Feb. or March. Using a calibrated digital scale that displays to 0.01 g, I have found that the ratio error has been no more than 0.25% and has been as low as 0.09%. I'm not sure how long it will take until the pump becomes less accurate because of seal wear, the check valve gunking up, or something else. But, this is the data I have collected thus far and thought it might be helpful for others to see actual data. Anyone else have similar data for a longer period of time? I have been using EZ Poxy the whole time I've had the pump. I have heard that less than 5% mix ratio is acceptable and read in one of the CP's that RAE would tolerate 10 or 15 % (going from memory here) mix ratio error. I agree with Gary that when the pump error starts increasing, I won't be able to tell while I'm pumping. I've purposefully mixed epoxy with a ratio error of greater than 5% and couldn't tell from scratching the cured epoxy. The error was somewhere between 6 and 10%. Scratching can indicate gross mix error, but IMO, scratching can't weed out marginally unacceptable mix errors. John Fritz fritzx2@aol.com From: cdenk@ix.netcom.com Date: Mon, 17 Aug 1998 18:21:14 -0500 (CDT) Subject: Re: COZY: Cheap epoxy pumps On 08/17/98 14:20:42 you wrote: > >Hi to all, > > Great discussion on pumps! I too have been thinking of different >ways to pump. How about using containers and pumps from a resturaunt >supply store originally used for condiments? There are some made of >plastic and also stainless. I know two stainless ones are about $200 >but maybe one can pick some up used. The pumps are about 6 or 7 >dollars for 1/2 dozen and come with a assortment of lids. One could >set the ration on the hardner by making a stop and double checking the >ratio with an accurate scale. What do you think? > >Mark > >(Waiting for the plans....) > > > > >_________________________________________________________ >DO YOU YAHOO!? >Get your free @yahoo.com address at http://mail.yahoo.com > > > What are seal materials, and repeatability of measured amount. From: mikefly@juno.com Date: Mon, 17 Aug 1998 19:55:40 +0000 Subject: Re: COZY: The cheapest epoxy pump To me, the cheapest & bestest epoxy pump is no pump! I've been using a one cup balance since the start of my project. I was told the plans for this balance were in the Dragonfly plans. I drew up my own plans from a balance a Q-200 builder was using. Unit has a slide weight to first balance the cup. Then a weight to balance the resin by setting it on the arm opposite the cup after resin is added. A third weight is set on top of the resin weight that represent the hardener. Hardener is then added to the resin until the scale balances again. This balance is adjustable to any system by changing the size of the resin and hardener weights. I know this sounds like a lot of work to mix one cup of resin, but in 15 years I've never had to clean it or wonder about it's accuracy. It's all ways ready when I am. The original balance used 1/8" piano wire and brass tubing for bearings. I substituted the brass tubing with 1/8"I.D. X 1/4" O.D. ball bearings." Works great, lasts a long time" If any one would like a copy of my plans, I'll post my address here so you can send SASE Mike TwoEZ MS1 _____________________________________________________________________ You don't need to buy Internet access to use free Internet e-mail. Get completely free e-mail from Juno at http://www.juno.com Or call Juno at (800) 654-JUNO [654-5866] From: "Greg Bakker" Subject: Re: [canard-aviators] RE: COZY: The cheapest epoxy pump Date: Tue, 18 Aug 1998 20:22:35 +1000 Gary has some valid points on epoxy ratios, I bought Philips (made in Austria) HR2385 kitchen scales from my local electrical retail store for $69 Australian. Actually I bought them for my wife (a chef) to use in the kitchen and she hasn't seen them since. They will weigh up to 5,000 grams in 1g increments with virtually no error and there's a safety cut off if the batteries are too low to provide an accurate reading. They are easy to keep clean, just cover them loosely with cling wrap or saran wrap (change it regularly) same goes for your calculator. The 9 volt battery seems to last for ages, I've completed my fuselage and numerous other parts (and my wife a batch of biscuits) and I have only replaced the battery once. Happy building, Greg Bakker, Australia VE under construction. ---------- > From: Hunter GA (Gary) at MSXSCC > To: 'Cozy Mailing List' ; 'Canard Aviators' > Subject: [canard-aviators] RE: COZY: The cheapest epoxy pump > Date: Tuesday, August 18, 1998 7:30 AM > >For the > homebuilder's environment, I favor a "Good" digital scale and a 2 bit > calculator over dispenser pumps. No matter what resin system you are > using, you can depend on it being as accurate as you are - anytime. > >> > > -----Original Message----- > > From: Lee810@aol.com [SMTP:Lee810@aol.com] > > > > I was looking at the West epoxy pumps recently and concluded it would be > > easy to modify them to virtually any ratio > > > > You must make sure that the pumps are properly primed and once that's > > done, > > it's as easy to use as my $225 Michael pump. > > > ---------------------------------------------------------------------- > For details on sponsors of this list, copyrights, and how to remove > yourself from this list, please visit: > > http://www.canard.com/ca-ending.html > > (c) 1997,1998 Canard Aviators. support@canard.com > ---------------------------------------------------------------------- Date: Mon, 17 Aug 1998 20:23:16 -0400 From: Bayard duPont Subject: Re: [canard-aviators] RE: COZY: The cheapest epoxy pump Boy, I can't agree less! There is much less chance of error with a pump if some care is taken while using it. I built my entire Defiant with one and never had the slightest trouble with it. I cant imagine trying to do some of those huge layups without the pump! Bayard duPont Hunter GA (Gary) at MSXSCC wrote: > [The Canard Aviators's Mailing list] > In my opinion, epoxy ratio pumps and dispenser tops for resin jugs are > not practical for the homebuilding environment. The epoxy ratio pumps > are swell pieces of machinery that work well when used frequently and > well maintained. > However, when you combine the inherent characteristics of the resins and > curing agents with the infrequency of use typically seen in most > homebuilders garages, you are bound to have problems each time you go to > use it. The resin frequently crystallizes and plugs the lines or fowls > the check valves, etc. The curing agents are corrosive (to varying > degrees) and damage the metallurgy and/or plastics. > > This can and does effect the pumps ability to dispense accurate ratios. > Much of this goes on without any visual clues. All this gives me the > willies to think y'all believe you have something reliable and > accurate. And now that I keep hearing about y'all changing from one > resin system to another. WOE !! > > The plastics and metals in these pumps are sometimes tailored to > specific resins and more importantly the curing agent. You change out > the curing agent and it might corrode the check valves and pump > seals. Next thing you know your ratio is off. IF, and I mean big IF, > you catch it, it takes a half a day of building time to clean and fix > the pump. Two months later, it does it again. > > Is it really worth it to have the luxury to push a lever and squirt > resin in a cup ? Again, this is my professional opinion - this is no > place to be complacent. I am not knocking Michael Engineering - I > recommend their equipment to my customers all the time. However, these > are industrial environments that use the equipment daily. For the > homebuilder's environment, I favor a "Good" digital scale and a 2 bit > calculator over dispenser pumps. No matter what resin system you are > using, you can depend on it being as accurate as you are - anytime. > > I encourage each of you to take a look at the scales available at > http://www.balances.com/index.html > > Through these folks, you can buy a Ohaus LS2000 that will weigh up to > 2000 grams in 1 gram increments for ONLY $83.00 - OR, the ACCULAB > V-4000 that weighs 4000 grams in 1 gram increments - ON SALE for $119. > These are both AC/DC (9V) , and very portable. > > I do not recommend the Pelouze scale being sold through Aircraft Spruce > or Wicks as it only weighs in 2 gram increments. Nor would, I fool > around trying to obtain something from the Office Supply stores either. > Unless things have changed, I found they generally don't have the > capacity or the accuracy. Ohaus and Acculab are laboratory quality > equipment. > > Once you have a scale like this, you can use it for a myriad of things. > Weighing parts you built or lightened, balancing your engine components, > etc. They are very handy. Practically no maintenance at all. Just > keep it clean. > > If you change resins mid-stream, it works the same way no matter the mix > ratio. Keeping a little cheapy 2 bit digital calculator close to the > balance will allow you to calculate the exact curing agent amount. Tare > the balance and add the curing agent directly to the cup with the resin > in it. No transferring - No waste. The calculator will get all gunked > up after awhile - so chunk it, get another one and go on. > > I have never had a bad batch of resin resulting from the equipment. Nor > have I ever wondered if I did while cruising at 10,000 ft. > > KINDEST REGARDS, > Gary Hunter > Technical Service Representative > EPOXY RESINS TECHNICAL INQUIRY > SHELL CHEMICALS, USA > > e-Mail - gahunter@shellus.com > > > -----Original Message----- > > From: Lee810@aol.com [SMTP:Lee810@aol.com] > > > > I was looking at the West epoxy pumps recently and concluded it would be > > easy to modify them to virtually any ratio > > > > You must make sure that the pumps are properly primed and once that's > > done, > > it's as easy to use as my $225 Michael pump. > > ---------------------------------------------------------------------- > For details on sponsors of this list, copyrights, and how to remove > yourself from this list, please visit: > > http://www.canard.com/ca-ending.html > > (c) 1997,1998 Canard Aviators. support@canard.com > ---------------------------------------------------------------------- From: "Hunter GA (Gary) at MSXSCC" Subject: RE: [canard-aviators] RE: COZY: The cheapest epoxy pump Date: Tue, 18 Aug 1998 10:12:48 -0500 John wrote > This also gave me reason for concern. For this reason, I have > calibrated my J & B pump over 20 times during the last 5 - 6 months of > use since I first put it into service (brand new) back in Feb. or March. > Using a calibrated digital scale that displays to 0.01 g, I have found > that the ratio error has been no more than 0.25% and has been as low as > 0.09%. I'm not sure how long it will take until the pump becomes less > accurate because of seal wear, the check valve gunking up, or something > else. But, this is the data I have collected thus far and thought it > might be helpful for others to see actual data. Anyone else have > similar data for a longer period of time? > It is good you are checking the pump in this fashion and I encourage you to continue doing so as long as you use it. Industry requires daily and even twice daily calibration of their pumps to be certain mix ratios are accurate. And their pumps are quite bigger and more sophisticated than the little tykes we have available to us. > I have been using EZ Poxy the whole time I've had the pump. > > I have heard that less than 5% mix ratio is acceptable and read in one > of the CP's that RAE would tolerate 10 or 15 % (going from memory here) > mix ratio error. I agree with Gary that when the pump error starts > increasing, I won't be able to tell while I'm pumping. I've > purposefully mixed epoxy with a ratio error of greater than 5% and > couldn't tell from scratching the cured epoxy. The error was somewhere > between 6 and 10%. Scratching can indicate gross mix error, but IMO, > scratching can't weed out marginally unacceptable mix errors. > Good observations John, right on the money. A scratch test is a crude but acceptable test for catching gross mix errors. Some resins / curing agent systems are more sensitive than others to mix ratios. Hopefully, aircraft design safety factors are sufficient to allow for the differences in physical properties resulting from minor errors in mix ratios. However, there is no way to design in a safety factor for fuel resistance. For some curing agents, the mix ratio is fairly critical in this regard. Therefore, it is a good practice to make sure you measure it as accurately as possible - within reason. 1 gram increments is sufficient. KINDEST REGARDS, Gary Hunter Technical Service Representative EPOXY RESINS TECHNICAL INQUIRY SHELL CHEMICALS, USA E-Mail - gahunter@shellus.com From: "Hunter GA (Gary) at MSXSCC" Subject: COZY: RE: [canard-aviators] Containers for epoxy... Date: Tue, 18 Aug 1998 15:45:34 -0500 > For easy dispensing, I keep my epoxy in the plastic quart bottles that > MEK came in (again from work ), and the hardener in Hershey's > chocolate squeeze bottles! The one with the airtight pull-up pouring > nozzle that snaps back in place when done. > > Harley > I like the Hershey bottle idea for the curing agent Harley..... I do the same type thing. You can squirt out curing agent fast when you need a lot, and stop it on a dime (or a digit in our case). The small snap top closure helps to keep the curing agent free from contamination and doesn't get all gunked up like a screw closure. Gary Hunter From: N27EZ@aol.com Date: Wed, 19 Aug 1998 21:55:54 EDT Subject: Re: Re: [canard-aviators] RE: COZY: The cheapest epoxy pump In a message dated 8/18/98 6:41:18 AM, dupontrotors@chesco.com wrote: < [The Canard Aviators's Mailing list] > In my opinion, epoxy ratio pumps and dispenser tops for resin jugs are > not practical for the homebuilding environment. > Gary Hunter >> Ditto here. I used a good ratio pump for the 50 gallons it took to build my defiant, and it never gave me a bit of trouble, and would not build without one. I built a varieze with the old balance beam system, and it was a pain. John Steichen From: COZYMK4@aol.com Date: Thu, 20 Aug 1998 23:42:06 EDT Subject: Re: COZY: The cheapest epoxy pump My first Epoxy pump was (almost) free. When I started with plans #90, I was too poor (and too mechanically challenged) to create the scale that was in the plans. Late one night I figured out how to make a pump. I used 2 teflon IV stopcocks that I had available in my doctor's office, 2 60ml syinges that we used to scare patients with and some tubing that was available at the hardware store for $1.00. I used as the reservoir, 2 baby formula cans with the plastic lids. The remainder of the material was scrap wood, a "Vote Cassingham, Sherriff" sign and some sawed off 16 penny nails. When I pulled back on the lever, the syringes filled to the desired amount (any amount including 1 cc), then turn the stop cocks and push foreward on the lever to the 2 tubes that were supported with spiral wound baling wire. This pump lasted me for 2 years until I changed from Safety poxy 2 to PTM&W. The new pump was made the same way with new cans and a clean sign (platform). It lasted for a year until my wife bought a Wicks pump for Christmas. The pump has larger bore so it flows faster than the little IV stopcocks and we didn't have any more accident of the plunger rod being pulled off of the plunger rubber by violent draws. I solved most of the plunger disconnects by using a baggie tie wrap wire around the plunger rubber groove. I wrote this story up as an article for Kitplanes but after 2 years, they sent it back with the photos of the new and well used pumps. I offered some syringes and stopcocks for postage but I now belong to a group that pays me enough to afford a plane and can't take home a few surplus items like when I was solo. I miss using my old pumps now but... Kevin Funk Cozy MkIV #90 Chapter 23 From: Lee810@aol.com Date: Tue, 8 Sep 1998 02:20:29 EDT Subject: COZY: MGS epoxy In a message dated 9/7/98 4:29:38 PM Mountain Daylight Time, jodyhart@communique.net writes: > Because of the recent posting regarding the MGS 285 hardener > reacting with the plastic of the Sticky-Stuff dispensers, I bought the > electronic postal scale from AS&S. The problem is not a reaction with the plastic, but rather crystallization of the MGS hardener from exposure to CO2 in the atmosphere. It crystallizes much more quickly than other epoxies I've used. To avoid this, you much keep the hardener reservoir sealed to prevent atmospheric exchange. My reservoir has a small razor slit in the lid to allow air to enter, but it still seals well enough to prevent the hardener from crystallizing. A plastic baggy that clamps under the lid and expands down into the volume as the hardener is used would be a better solution. I have also begun covering the hardener spout with finger cut from a used latex glove and a rubber band to secure it to prevent the crystals from growing on the spout of the pump. Without protection, in several days, enough crystallization occurs that you have to remove it with a sharp implement to unclog the spout. > A little five-minute epoxy goes a looooong way. I am afraid of what > the back of my seatback is going to look like when I pry it off the > table! Most of the fixturing called out for 5-minute can be done with a hot glue gun with much less damage to the foam. I found that if the 5-minute wicked out so far and soaked in so well that the pockmarks were absolutely huge. > I didn't have as good of luck with the Invisible Gloves as I had > hoped. I don't know if it has to do with the MGS or not, but I will > definitely be purchasing some "visible" gloves for the next lay-up. Latex and vinyl gloves work fine until you get your first reaction. I did about 50 layups before I got my reaction while using latex gloves. The best protection is to get a pair of butyl gloves which are around $12 and then use the disposable latex gloves to protect them. Barrier creams remind me of the emperor's clothes. Lee Devlin LongEZ N36MX Cozy MKIV under construction http://members.aol.com/lee810