Filippo Morelli wrote:
I don't weigh my DA. I add after. Maybe Stuart has opinions on this?
Measure the A & B by weight...I always mix 5 grams each for 10 grams total. Then mix it thoroughly. Then zero out the scale with the mixing stick in it and add 1 gram of alcohol.
Note that the A and B components have SLIGHTLY different densities so weighing equal amount of Zpoxy doesn't provide the ABSOLLUTE perfect ratio but it's well within the margins and weighing provides a very consistent result. That's the key to weighing.....consistency.
Experimenting with alcohol ratios, you'll find that increasing the alcohol with Zpoxy yields an increasingly softer rubberized puck of cured material. Not that a little rubberization is going to foil you, but it will at some point, I expect. I got a little scared of using 20% alcohol because of this...but it still sanded fine.
Actually, there could be a case to be made that rubberizing the epoxy under a finish could improve impact strength. It could also be that rubberization could improve adhesion to nitro, maybe even eliminating the need of a shellac binder...or even the sanding of the last wash coat for that matter. The rubberized texture of the cured epoxy could indicate free radicals on the surface, which are typically not found with cured epoxies. Usually, with fully cured epoxy the surface it utterly inert. But if mixing alcohol into Zpoxy leaves a reactive surface it's entirely possible that the bond between the rubberized epoxy and nitro ends up being a molecular bond...and inseparable as a result. I couldn't possibly say this is the case but testing this theory would be easy enough.
Not that I'm ever going to test it.
I'm spraying catalyzed polyester for pore filling these days...and loving it. Answer to my prayers....polyester.
