Black specks in fiberglass

[Mac32]

I have a really weird one here. There are patches of black specks in my fiberglass, similar to when you get overspray on the boat.

This is actually what I thought it was until I started pulling trim off, removing the original paint stripe and found these specks in the gel coat under areas covered by the factory.

Its in random spots all over the boat from fly bridge top to deck sides. Millions of spots and I can get them to go away, a little (not completly) with heavy rubbing compound and heavy pressure on the buffing wheel. The fiberglass also seems to be a little rough in these areas almost like the gelcoat is pitting in these areas.

Any ideas on this one guys. Its not overspray, its in the gel coat and its driving me nuts...........Could it be mildew in the fiberglass?

Maybe I should try bleach on it?

[gofish103]

could be mold, but mold shouldnt pit the fiberglass,

has anyone been welding near your boat?

[LandVF36]

Could be dirt or mold. When Gelcoat breaks down, it does get very pourous. If that is what is going on, the bleach won't hurt it. If it is mildew or dirt, it really needs to get cleaned up before you seal it.

Prior to sealing an aging fiberglass hull, I've used bleach, throughly rinse, let it set a week. Then used Interlux 202 solvent to clean the fiberglass. Rinse and dry a day and then Interlux 303 prior to applying a prime coat.

If it is breakdown, you are going to want to seal it up soon. Letting it go will lead to moisture getting into the fiberglass matting and you want to stop that form happening asap.

[guglielmo6160]

its probably mold, I have a similar situation in the vinyl of my seats, try soft scrub with bleach, that may work,

[Stripermann2]

I vote mold as well...

[MattSC]

I had some black specs in my non-skid on the foredeck. I used tide with bleach (Powdered) with a stiff scrub brush. It took care of it and made the non-skid look great. Beware though it will remove wax. I learned this through a conversation with a boat detailer at the Norwalk boat show.

[jddens]

The powdered tide with bleach works great on teak as well.......make a paste, scrub, rinse, dry and oil..............

[oldsun]

First - The black spots are mold and unless you are going to paint the boat I would not try to hard to get rid of them. Just give it a good wax job and keep your eyes on the water ahead. If you use heavy rubbing compound and heavy pressure you will soon get more trouble than the spots. Poly resin and gel coat will "scorch" leaving area brittle and prone to chipping and flaking. Once that happens it big buck prep time before paint.

Second - TSP, Tide with out the marketing, from the hardware store and water just as hot as you can work with will make short work of dirty teak. Make the past to start then use it like a sourdough starter and keep adding powder and hot water. Work fast with a stiff brush, but let the past do most of the work. Mess with it a little and you will find the combination of scrub and wait time to keep the job moving. You work forward and rinse backward so that by the time you get around the boat, it's done. DO NOT let the past dry and or set up - leaves spots and patches.

My shot for this evening, and remember we never go stright, we go forward.

Scott

[Mac32]

Yep, my bet is now mold. Denatured alcohol, no touch, rubbing compound, too deep to touch,,,,Bleach, .......All gone.

They are really little specks and the wife still thinks I am crazy because she cannot see them, But I can and that's all that matters, So now I have found a cure thanks to this forum.

Thanks

[oldsun]

mac,

Be sure to put a good coat of wax on after the spots are gone or you will set up the condition for more to "grow". Glad you got the fix.

Scott