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I was wondering if anybody could give me some advice on US Composite's epoxy for my Wildman Punisher 3 build. Mainly, I just want to know which resin and hardener I should get for fin fillets. The medium hardener seems to be the one recommended by US Composites, but then should I use the thick or thin reason. Will this combination be heat resistant enough for the fillets on the mmt? Additionally, should I add some chopped fiberglass to my fillets?
 

C.O.B.H.C.

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I would suggest the 635 THIN EPOXY SYSTEM Medium and getting Cab-O-Sil and milled glass as the thickener for the fillets. I have used the US Composites 635 THIN EPOXY SYSTEM to build a 75mm minimum diameter and fly it on an AeroTech M775W (this was the prototype to the M685) and it held up fine.
 

rharshberger

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Having used both the thick is only a bit thicker than the 635 Thin, both need to be amended with Cabosil (I also add the 1/32 milled glass fiber) to thicken. Phenolic micro ballons and wood flour make a nice fairing compound that sands easier than the Cabosil amended epoxy. The cured epoxy emwill be fine for the mmt fillets.
 
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