Mysterious Black Spots

riverfisher · 06-16-2006, 04:14 PM

Hi All,

I have thousands of small pin head size black spots on my boat. These spots are hard shelled and stain the fiberglass. These spots are on the aluminum window frames, stainless steel railings, Galvanized trailer and from the top of my cabin to the water line on the fiberglass. I have a galvanized anchor on the pulpit of my boat and the spots are on the lower side of the anchor. I'd like to know what these spots are and how to clean them off my boat. I've tried accetone, paint thinner, rubbing compound, bleach, three different bottom cleaners containing various levels of acid, three different types of goop off. The goop off works the best with lots of scrubbing but doesn't completely remove the stains. My boat is a 1990 blue on white. The gel coat is mostly gone on the top decks where the stains are the greatest. I've talked to two boat yards with photo's and no help. Not a lot can be seen with photo's. Has anyone had the same problem and found a way to clean these stains. I suspect bug juices but can't prove it and can't clean it.
I'd appreciate any ideas. Thanks.
Dick the riverfisher.

06-16-2006, 04:14 PM	#1
riverfisher Junior Member Join Date: Jun 2006 Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts	Mysterious Black Spots Hi All, I have thousands of small pin head size black spots on my boat. These spots are hard shelled and stain the fiberglass. These spots are on the aluminum window frames, stainless steel railings, Galvanized trailer and from the top of my cabin to the water line on the fiberglass. I have a galvanized anchor on the pulpit of my boat and the spots are on the lower side of the anchor. I'd like to know what these spots are and how to clean them off my boat. I've tried accetone, paint thinner, rubbing compound, bleach, three different bottom cleaners containing various levels of acid, three different types of goop off. The goop off works the best with lots of scrubbing but doesn't completely remove the stains. My boat is a 1990 blue on white. The gel coat is mostly gone on the top decks where the stains are the greatest. I've talked to two boat yards with photo's and no help. Not a lot can be seen with photo's. Has anyone had the same problem and found a way to clean these stains. I suspect bug juices but can't prove it and can't clean it. I'd appreciate any ideas. Thanks. Dick the riverfisher.