nadt770 Posted January 31, 2006 Share Posted January 31, 2006 A search on this doesn't get me much. What is this and where can I find some more info? Thanks. John Quote Link to comment Share on other sites More sharing options...
Jon Matcho Posted January 31, 2006 Share Posted January 31, 2006 A search on this doesn't get me much.Must be the wrong search. Open Cozy newsletter #76 here and search within for 'hard shelling'. I found that by searching here for 'hard shelling'. I will admit that was NOT what I thought 'hard shelling' was... Quote Jon Matcho Builder & Canard Zone Admin Now: Rebuilding Quickie Tri-Q200 N479E Next: Resume building a Cozy Mark IV Link to comment Share on other sites More sharing options...
nadt770 Posted February 1, 2006 Author Share Posted February 1, 2006 O.K. thanks. I used "hard shell" for the search. Looks like it is not a good process. Quote Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted February 1, 2006 Share Posted February 1, 2006 O.K. thanks. I used "hard shell" for the search. Looks like it is not a good process.You might want to search the COZY mailing list archives before making that judgement. There have been many discussions over the years on this technique, and it has it's place. When done correctly, the strength is more than adequate. Quote Marc J. Zeitlin Burnside Aerospace marc_zeitlin@alum.mit.edu www.cozybuilders.org copyright © 2024 Link to comment Share on other sites More sharing options...
argoldman Posted February 1, 2006 Share Posted February 1, 2006 You might want to search the COZY mailing list archives before making that judgement. There have been many discussions over the years on this technique, and it has it's place. When done correctly, the strength is more than adequate. On my dragonfly, I hard shelled the wing and wet lay-upped the canard. I found the hard shelling to be much more time consuming with little real benefit. If I were to hard shell again, I would peel ply the micro smear.-- I shell not do it again, however! Rich Quote I Canardly contain myself! Rich Link to comment Share on other sites More sharing options...
Steve Innova Posted February 1, 2006 Share Posted February 1, 2006 Hard shelling can allow you to do big layups by yourself. The problem I've found w/the conventional approach (spreading micro on surface, then laying down cloth, and then expoxy) is that if you have to move the cloth at all (to straighten the fibers) it tends to pull up the wet micro, leaving patches of foam without micro. This is just a cosmetic issue, as the epoxy still soaks through the cloth and into the foam, but it makes the surface look ugly. On the other hand, hard shelling allows you to easily slide the cloth back and forth to get the fibers perfectly straight. There's no wet, tacky micro beneath to grab the cloth and distort it. This allows you to do big layups by yourself, and it also allows you to break the layup into two parts -- the micro hardshelling, and then the cloth/epoxy application. Quote Link to comment Share on other sites More sharing options...
Neverquit Posted February 1, 2006 Share Posted February 1, 2006 Nice concept but it didn't appeal to me. I tried it on a section of the nose to repair an area. After the top plies hardened I could press against it and it would make cracking sounds like celery or nachos. I'm assuming the hard micro is cracking beneath the glass plies. It doesn't appear to be as strong as when the foam gets wet microed before the plies. Quote Link to comment Share on other sites More sharing options...
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