oh wow... oh god...
oh no....
no, no, no, no.... no, no, no, no, no.
Fiberglass isn't something you can just toss on and sand and hope to get that glassy look. I have a page of tips and tricks for working with it on my sounddomain page,
www.sounddomain.com/id/andrave
scroll through the pages, it is a couple pages deep.
I'm in the process of redoing my box right now but my old fiberglass projects (240sx and escort) are both up.
IM aol sn andrave cause you sound like you have no clue what you need to do.
first off, fiberglass cloth has to be used with fiberglass resin. fiberglass resin has to be used with hardener.
I'd really have to see your box to know exactly what your plan is but Im guessing its probably relatively square and mdf. all you need to do is apply some bondo and sand it and paint it if all you want is that glossy paint job, follow the painting instructions on my page.
however, if you really want a curvy, swoopy enclosure, its gonna take more than glassing over an existing mdf box.
My guess is that throwing that fiberglass filler on there has made you a surface that is lumpy as hell. a really big problem with fiberglass is that it dries as hard as cement. Find a rotary sander and use a really aggressive grit sandpaper to take it down.
anyway I'd need to know more about what you are starting with and what you want to acheive to really be able to give you good advice.