I've been researching this forum for a while now.
I used to run an Automotive Refinish Supply Store Chain,(two, untill screwed out of by EXwifes Father).
The $30 per gal range is a GOOD price.
Read instructions and use hardner as per!!!
Fiberglass "Matting" being multi-directional will made a better and stronger unit BUT,
It's use is a bit more MESSY and harder to use, when I get to that point on my own builds, I'll use one layer of each on each side, (Cloth, Matting, COILS, matting then cloth), And thinner is better. I saw/read somebody using a D/A sander on top of mold to vibrate out bubbles, GREAT IDEA !!!
Also there is a "FiberGlass Epoxy" Resin also, mix = 1 to 1, Much better product but about twice the money.
I see you people using "filler's", tac ect... Works but will be less strong!! Serious!!
I'd use more Matting as filler, the muli-directional glass fibers will give MUCH BETTER STRENGHT.
I've never seen any PRO shops use powder fillers on Vett's and I've never done so.
Just my $0.02
l8r