When it comes to thickening epoxy, I know of three different classes of product: flox, or flocked cotton, which is basically shredded cotton fibers; cab-o-sil, which is "fumed silica"; and micro-balloons, basically microscopic hollow glass spheres. All three have been mentioned numerous times on the forum, usually in the context of thickening epoxy, but I don't have a clue what the practical differences are. I'm guessing that cab-o-sil and micro-balloons are lighter than flox, but I'm not sure. Can anyone describe the practical, "Why pick one over the other" differences between these products?
