Years of grime in Gel Coat body

[hi-tech cobra]

I’m starting to work on the body after the car has been sitting for many years. We washed it but noticed a film of dirt and grime is stuck in the gel coat. Testing a small area, solvent Goof-Off removed it as did lacquer thinner and last but not least Fabuloso with a scruff pad. The first 2 (solvents) methods also removed some of the gel coat and caused it to gum up. The fabuloso/scruff pad method took forever but worked.

Is there a better way to clean off the in ground grime before hitting with primer?

[MOTORHEAD]

Try Acetone, It's what boat builders use it to clean their molds. It evaporates quickly, so it doesn't soften the gel-cote.

[hi-tech cobra]

Good idea, thanks. Was also thinking about pressure washing.

[olddog]

You might also try scrubbing, as before, only add dawn dish soap. It is a fairly good de-greaser that is relatively mild. Maybe get it as clean as possible with reasonable work, before hitting it with the harsh chemicals. Then you shouldn't need to keep the harsh stuff on so long.

[mrmustang]

Originally Posted by hi-tech cobra

I’m starting to work on the body after the car has been sitting for many years. We washed it but noticed a film of dirt and grime is stuck in the gel coat. Testing a small area, solvent Goof-Off removed it as did lacquer thinner and last but not least Fabuloso with a scruff pad. The first 2 (solvents) methods also removed some of the gel coat and caused it to gum up. The fabuloso/scruff pad method took forever but worked.

Is there a better way to clean off the in ground grime before hitting with primer?

From the retired bodyshop owner here on the site

Interlux brand fiberglass surface prep, part number YMA601
and
Interlux 202 fiberglass solvent wash


Use a gray scotchbrite pad and make certain to flush with water. Do not apply in the direct sunlight. Carefully read all instructions.
Both of the above are low VOC, modern day mixes.



Bill S.

[hi-tech cobra]

Thanks olddog and mrmustang. Being impatient I didn’t want to wait for the Interlux product but it does look like a great solution. So I tried something under the cabinet: Totally Awesome cleaner degreaser. Using a Grey scruff pad....the grud came off with minimal effort and didn’t attack the gel coat badly.

[CSX 4133]

Try a medium clay bar and quick detailer, spray an area with the detailer and run the clay bar over it. As the clay bar picks up debris, refold it to a clean section and repeat.

[mrmustang]

Your going to need a cleaner to clean that cleaner residue off the gelcoat, especially if you plan to prime and paint down the road.

Bill

[hi-tech cobra]

mrmustang will a wax and grease remover do the trick?

[mrmustang]

Originally Posted by hi-tech cobra

mrmustang will a wax and grease remover do the trick?

Automotive grade only, yes..

[hi-tech cobra]

I’m going back over it with dawn to take as much off as possible before using a wax and grease remover in hopes of creating a clean surface before the sanding begins.

[hi-tech cobra]

How do I fix a fiberglass crack behind the drivers seat in the rolled edge (see pic). You can see the crack open up when you push. So I think it’s more than a gel coat crack. It needs to be strong and support the area. Don’t know how to fix, maybe fiberglass mat and resin? Also how do I address the large cracks in the gel coat? It looks like bubbling between the gel coat and fiberglass.

[hi-tech cobra]

It looks like it happened when it came out of the mold.

[mrmustang]

3m Dynatron fiberglass resin #694
Built up in small layers over the course of a day or two.

You will need to chip away all affected areas until you reach a solid substrate

Bill S.