Yellow hull stains
 

What's the strongest cleaner to rid this yellow stains?
It's under my swim platform around the drives and steering rams.
I have tried Sno Bol, Ring-Go, and buffing/cleaner compound. None of that stuff does anything.

Simple Green lightens it's a bit.

It comes right off with 2000 grit sandpaper, so it is just some type of crud on the surface. Don't want to have to sand it off just because can't get a buffer into most of the areas to rebuff.

So, what's the strongest: On-Off, Slimey Grimey, Or FSR?

Thanks
Jerry

Shower power

On-Off works well,but wear old clothes when using it.

Try Flitz. Light rubbing and it's gone.

bleech white
 

some bleech white tire cleaner does the trick for me!! be sure to wax after!!!

FSR works well for what you describe.

If FSR doesn't work well enough, then go with the wet 2000 paper. Don't need to chase it with a speed buffer: just hand buff with white polishing compound and then a finishing wax.

Orange Blast Wheel Cleaner(not degtreaser)

Spray on and in seconds it's white. Rinse off:)

And it's cheap because nowhere on the bottle does it say "marine";)

50/50 mix muriatic acid and water or Castrol Super Clean at about 3 to 1. Use the acid in a spray bottle and follow with water. The acid is already a .05 mix so I guess you are using at .025.

Like BadDog says, muriatic acid works well. Spray in on with a plant mister. You can use an old toilet cleaning brush to scrub if necessary. But it usually works by just letting it sit for a few minutes.

Be SURE to stay up wind of the stuff, it's very caustic. The fumes are real nasty. Wear gloves and a mask if you have them. If not, be sure not to get the acid on your skin, and again the fumes are caustic.

Rinse it off real well, then wax.

I've used the green hull cleaner from west marine. That stuff has the muriatic acid I believe and works very well. Have also used lime-away on the tips to take off the chalkiness and it cleans the white very nicely if you let it drip down the transom....as others have said be careful of fumes.....gloves and a mask are in order. Of course a very thorough rinse is in order when using these products also :)