Are you completely set on using West? As I recall (although I don't recall where the numberrs come from) West System doesn't develop properties with post curing as nice as some other epoxies. For instance, I have an epoxy mix picked up from a boatbuilder I know which has a considerably higher glass transition temperature after post cure. ( but again, it's been so long I don't recall exactly what those properties or cure temps are).
For a small job like this, I'd probably use Phase Two from an outfit called System Three. You will get a paper telling you exactly how to postcure it. (Two hours at 140F, but it has to be that warm all the way through). An unusual property is that it becomes relatively opaque because of the two phases, which are supposed to make it tougher than a singly phase epoxy. Not sure if this works in terms of strength and toughness, but it handles ok. Heat deflection temp claimed as 64C (147F) For a big job I'd go back to that boatbuilder I know or else look into Raka as mentioned below. If I thought the volume was going to be pretty high I'd definitely look into prepregs. Probably save a lot of labor and get better properties too, although I haven't played with prepregs yet. Your oven might not be enough for them, though. I seem to recall MGS (sp?) epoxies are made for postcure as well. You might try Raka. The proprieter is willing to talk to you on the phone, and can recommend temperatures etc. for various epoxies he has. If you pick the right materials and cure it right, you can use colors other than white, although I certainly wouldn't do it with West. If you must use West, it sounds like 120F for 4 to 8 hours is good. I found it in the following newsletter from West: http://www.westsystem.com/ewmag/18/pdf/tanks.pdf Now, some of that epoxy is mixed slightly different, but not much. Don't exceed 140F: http://westsystem.com/webpages/userinfo/moreinfo/coldtemp.htm (that's a clue that you may not get great thermal properties) Note that, according to the physical properties on the West site, 105/206 is only good for 123F heat deflection temperature. That's why we need to keep it white! I think, given the labor involved, that if the results are important it's a false economy to use the epoxy on hand. Nothing wrong with WEST if you aren't going to use the result in high temps or need really high properties in the resin. In that case I'd use the ordinary version of RAKA because I've used it with good results in the past and it was cheaper. I realize that you probably have 10X the practical experience laying up glass stuff that I have, but I've looked into the post curing thing a little bit. Even if you stick with WEST, if you get it to 100F overnight it will be reasonably well cured overnight. But I understand post curing works best AFTER the initial cure. Bill & Bunny Kuhlman wrote: Granddaughter Alyssa and I are involved in vacuum bagging processes: carbon fiber spar caps, fiberglass over foam flying surfaces, and a molded all glass fuselage pod and boom. We're using West System 105/206 for all of the components. We know that post curing - higher than room temperature heat over several hours to a full day - will make the epoxy matrix stronger, but after a long web search have been unable to get firm numbers for either the temperature required or the recommended time period. If anyone can pass on this information, we'd very much appreciate it. We have our "hot box" made and can take it up to 160 degrees F. Many thanks in advance! -- Bill & Bunny Kuhlman RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED] Please note that subscribe and unsubscribe messages must be sent in text only format with MIME turned off. Email sent from web based email such as Hotmail and AOL are generally NOT in text format
