Outside of a chemical bath (costs $95) what is the best cleaner to take the green algae off the bottom of my boat from where it had set in the water at a boat slip ?
There's another product called FSR, short for fiberglass stain remover. It is basically a gel of oxalic acid. Does not seem to hurt the gel coat. I used it to get the "yellow" out of the white gel coat on a sailboat I used to own. Worked reasonably well. Most marine stores carry it.
You can use toilet bowl cleaner instead of on-off....it's the same stuff, just costs less. The Works is a good one...Snow Bowl is another.....Anything with oxalic acid or hydrochloric acid in a gel type liquid works very well on getting the algae and resultant stains off the gel coat. Make sure to rinse everything off very well with water after you use the acid....and be careful with it, gloves and eye protection are a good choice.
Most green algae will come off pretty easy with just a scrub brush if it is still wet. Clean it off right after you pull the boat out of the water.. The more often you clean it, the easier it will be to get off. I use starbright hull cleaner and it works good.
