Hot Rod Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
338 Posts
Discussion Starter #1
I have a pair of custom shaped running boards that are fiberglass covered wood. The boards have a lipped outer edge (drops down giving the appearance of a 2” thickness) then a horizontal tapered (front to back) surface and a vertical 4” surface that fits up against the frame rail. The verticals are fine, but the horizontal has a lot of waves in it I’d like to smooth out.

I figure I can block sand the flat horizontal surface-I don’t know if there’s fabric in the ‘glas or not- but it’s quite likely I’ll need some filler in spots. Should I use more gel or body filler instead?

Sorry if this is a stupid question-I am a bodywork idiot, but trying to learn.
 

·
Registered
Joined
·
734 Posts
5window said:
I have a pair of custom shaped running boards that are fiberglass covered wood. The boards have a lipped outer edge (drops down giving the appearance of a 2” thickness) then a horizontal tapered (front to back) surface and a vertical 4” surface that fits up against the frame rail. The verticals are fine, but the horizontal has a lot of waves in it I’d like to smooth out.

I figure I can block sand the flat horizontal surface-I don’t know if there’s fabric in the ‘glas or not- but it’s quite likely I’ll need some filler in spots. Should I use more gel or body filler instead?

Sorry if this is a stupid question-I am a bodywork idiot, but trying to learn.
Are these gelcoated or raw fiberglass?
 

·
Premium Member
Joined
·
4,097 Posts
Wash the entire part with wax and grease remover.

Block sand it with 80 grit to shape. If it is really rough you can use 40 grit. If you start to see alot of fibers becoming uncovered, rough up the low areas with 24 grit. If you see pinholes in the part, open them up with a knife or die grinder with a pointed burr before you spread the filler.
Fill with a good filler like rage or evercoat, scrubbing the first layer into the surface in several directions, then applying your fill thickness. Block with 80 until it feels good to you.

Prime the entire part with a good catalyzed filling primer like Evercoat feather fill,or Duratek makes some really good polyester and vinylester filling primers. http://www.duratec1.com/dp04.html

Those primers are designed to be used over fiberglass, and if applied properly they have many of the same properties as gelcoat. I like to apply it so there is an even 10 mil cured, to help prevent transfer and blistering. ( especially if the part is a chopper gun part or has alot of tiny bubbles in the laminate that don't get picked out.)


Block sand the primer to whatever grit your paint system requires and prime with the recommended primer.

Alot of people like to use an epoxy primer over fiberglass as a cheap form of insurance against paint failure from moisture getting in the substrate, and it adheres really well..
You can use it if you want to.

There are a bunch more threads like this on the site,

Here is one ,
http://www.hotrodders.com/forum/new-fiberglass-81391.html#post587506

Do a search for "blocking fiberglass", or "finishing fiberglass parts"

I'll bet your'e just "itching" to have some fun with fiberglass. :p

Later, mikey
 
1 - 3 of 3 Posts
Top