Quote:
Originally Posted by Av8torTom
I'm afraid epoxy and micro would not be flexible enough.
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Straight epoxy/micro will be plenty flexible and won't ever come off. For strongest bond, expose bare aluminum shortly before application (minutes) using sandpaper, or chemical etch with phosphoric acid. (Home Depot sells phosphoric acid in glycol for half the price of AS&S; they call it "Prep & Etch".)
Having said that, I made a bit of a mess when epoxy/micro dripped onto uncleaned oxidized aluminum while I was glassing in pieces of canopy. That reminder has been sitting there on thin fuselage skin for about five years unprotected; no signs of it ever coming off despite all my wishing. I also filled in some pop rivets with bondo: none ever fell out, also unprotected.
If you are really paranoid about flexing, thin the epoxy/micro mixture with 5% acetone and spray, that way you'll end up with shorter chains resulting in much weaker, more flexible polymer:
https://epoxyworks.com/index.php/thi...-system-epoxy/
Or simply use J-B Weld, which is a 3-4000 psi mixture with etchant, and nice matching color to boot! Heavier though.
Your biggest problems with epoxy/micro will be: it keeps sagging after application to vertical surfaces (use lots of fast activator, work fast) and, it takes quite some effort to sand because it cures so hard. Cracking and pieces falling off aren't on this list.
