Don't know much...
You know, I always wanted to try the stuff they use on automobiles for clearcoat... however, the only sources I could find wanted a LOT of money for a small amount. And it seemed the stuff was just another acrylic or urethane product anyway, from what I remember.
As the title says, I really don't know much, and I read many great posts, but the problem is... I am NOT in America, and the products and chemicals may vary so much, that sometimes it's hard to get anything close to what is discussed here.
Of course, I have the same problem, how to preserve (and harden) paper models. The best thing so far for me, since I have started at it just a couple of months ago, is craftmanship varnish (is that right?), for I've been told any other varnish wouldn't adhere to paper. Problem: it's water-based, so it won't protect the model from the rain, and as a previous post said, apply VERY light coats.
But I'm still testing it, and would appreciate comments on it, since I don't know much (here we go again...sign1) about paints and related stuff. Please remember: we do not have as many products here in Brazil (unless they are imported) as you guys have in America.
Thanks!