finishing fiberglass box

R. Clark,

   When I built my own fiberglass enclosure I wanted to paint it also.  I finished the exterior using Bondo body filler.  The worst part is all that sanding, were a dust mask!  To get a smooth enough surface to paint on you will need to wet sand the areas that will be painted with 600 grit sandpaper.  (I asked a buddy of mine that paints cars for a living and he was right.)  Once you've wet sanded your project, go over it with an eagle eye and get rid of any and all pin holes and unevan surfaces!  The surface will have a shinyness to it once you've sanded it.

  As far as painting goes, my buddy painted my box for $30.00.  If you or anyone in your family knows someone who paints cars try asking them.  You have to be really bad at painting to screw up a sub box!  If you've ever used a paint gun and compressor you might be able to pick-up some left over paint from an autobody shop and paint your own box.  See, after body shops paint a car, the paint left over can't be thrown away in the trash(hazardouse materials), so they would rather sell it than have to pay to have it hauled off.

Hope this helps!

Nick (Dynamic)

Thanks a bunch Nick,

But after bondoing and sanding, do you have to use some type of sealer over the bondo to keep the paint from soaking in?

                                                                                      R. Clark

No sealer was necessary on my box.  The only thing that I applied before having it painted was a couple of coates of primer that I wet sanded with the 600 grit sandpaper.  I've never had any problem with bondo soaking up paint as long as there was primer between the two.  So, after sanding the bondo down reletivly smooth using 400 grit sandpaper, apply a couple coates of primer.  Once the primer dries then wet sand the surface with 600 grit paper. 

Good Luck

Nick (Dynamic)

"The worst part is all that sanding, were a dust mask! "

i don't know the shape and design of you box so i cant give a lot of advice, but the one thing i can tell you is that you should use a polyester primer to cut down on the sanding.....you can go through and sand the fleece, or polyester trunk liner with an 80 grit paper and then if you have any big dips, you can fill them with the bodyfiller.....if you use a high grade filler like rage gold by evercoat you will get less shrinking in the small holes and not get pin holes...also by using the featherfill (polyester primer) next, you will have very few pinholes ..i recommend you use a product called icing to fill the pin holes in.  it is like a runny bodyfiller...its for finishing...it doesnt shrink either, and sands really easy as well...........installguy509