colemast

Usually I can figure out what gets certain types of stains off but this has me stumped
i am fishing more than ever since Covid and my cover is staying off all summer so far.
but 3 weekends in a row we got rain and this stain showed up under an ice chest.
Dingy gray in color.
I figured it’s organic of some type but can’t remove it. I have tried so far

1. bleach
2. magic eraser
3. kaboom
4. mr clean

Commocean

Barkeepers Friend maybe? I use it for a number of tough stains.

HeadHunt

Agree

kmoose

Test a small spot with some acetone. I don't normally use it on smooth surface gelcoat but have no issue using it on textured. Once its off, wax it.

Blue agave

x3

also UV light and time.

scott_gunn

I have the best luck with FSR (Fiberglass Stain Remover).

colemast

Ok, tried them all - even worse I scrubbed too hard with magic eraser - now that spot is shiny and stained.
I'm keeping the cover off and letting the louisiana sun work on -
bleach seemed to work better than anything.

Strange that I can't get an organic stain out -

Shewillbemine

Toilet bowl cleaner?

RCL

Soft Scrub with Oxi and a scotch Brite pad. Insert the rectangular 1 with a handle. Works great

Raybo Marine NY

try some lemon ammonia, make sure its lemon

auburntsts

Starbrite ultimate fiberglass stain remover

asdf78

On off.