2 of 4 people found the following review helpful
Removes organic / rust stains in fiberglass gelcoat.,
This review is from: Boeshield Rust Free (Sports)
I tried this on my 33 year old sailboat. I had some rust stains as well as some organic stains from water in which some leaves had collected, decayed and stained the fiberglass. Sprayed liberally and left sit on the organic stain for 3 or four minutes and wiped off, the stain was removed significantly. A second application made it almost disappear.
In fairness, Clorox might have done the same thing for a lot less!
The light rust stain was tried while still wet from overnight dew. The product was sprayed on and left to sit about 10 minutes then wiped off. The stain was reduced by about 70 percent in one application.
Last I tried it on a tiny bit or rust that was beginning on a stainless fitting. I really did not see much improvement there. Admittedly this was not a great test, but it was still the result.
This product contains phosphoric acid. Be careful. Keep off hands and out of eyes. Rubber gloves would be a good idea.
If you have stains on your raw gelcoat I say its worth a try. It got rid of the stains I wanted. I did not try it on rusty tools, metal or any such use.
I'd say it well worth a try on your stain if other products have failed. Try and buy locally if possible. The shipping kills the price.
You could also try Barkeepers Friend, a type of powdered cleanser containing oxyalic acid. You can also buy a liquid, wood stain remover containing a weak oxyalic acid. Both are somewhat effective against light rust stains.
Use the same cautions as above.