painting fiberglass
#2
That will depend on what your painting and what your painting it with. Check with your local AUTOMOTIVE paint supplyer. Some parts stores also carry auto paint, such as Oriley. Just look in your local phone book for automotive paint. Of course this is assuming you are planning to use a spray gun and automotive grade paint.
#3
Blow all the dust off, wipe down with prepsol, then a tack cloth. First coat needs to be a primer/sealer, then a high build primer for sanding. Some primers can do all 3. Sealing is important so any putty work doesn't bleed through. Each subsequent coat needs prepsol and tacked prior to paint.