"Yellowed" boats in Baltimore's Inner Harbor

[stevediebold]

In the past week, boats in the Inner Harbor have yellow stains that can not be washed off. The only thing that appears to work is rust stain remover which also removes the wax. Any one know what happened...ie...what caused this and if there is something else to use that won't strip the wax?

[jcollins]

Been there, done that.
I kept my Searay there in the late 80s. Same problem. Hated it. I never did find anyway to keep it clean. The yellow seems to be less or go away as the water temp rises. The bay temp was 59 yesterday.

John

[robertatthebeach]

I don't know if SimpleGreen will take the yellow off, but it will not strip the wax. Mix it about 10:1 and give it a try. I haven't tried higher concentrations, but the 10:1 usually does the trick. By the way, this is what I use to wash the hull with. Use microfiber towels (walmart, costco) to dry the hull with to take away the water spotting. The hull will return to freshly waxed, assuming you had any on it in the first place. 3M Marine Wax is the best I have ever used. I use it on everything. Every 4 months does the trick. Let me know if this works for you. Best, Robert.

[Cape Codder]

White vinegar can clean many things on a boat. Dried fish blood, stuck, dried-on fish scales, mildew, gull droppings etc.
Being a mild acid, it may get those yellow mineral stains back into solution. Try diluted 5:1, 2:1, and then undiluted if the others don't work.
The trick may be to start as soon as you detect stains, it may not remove heavy build-up.
When stains really get tough, I use "The Works" bathroom cleaner form K-mart. Less then $3 per spray bottle. Contains oxalic acid, just like expensive "hull cleaner" from West Marine or other suppliers....it's just much cheaper.
"The Works" WILL REMOVE WAX.

[Seaslug44]

SOFT SCRUB with BLEACH. That is the ultimate cleaner for fiberglass. Gentle enough not to scratch but just enough muscle to remove stuborn stains.

[Mariner]

How about a cleaner wax? You'd still want to follow up with a protective wax, but it sounds like you'll be doing this anyway.

The yellow stains, are they on the whole boat, or just at/near the waterline?

[stevediebold]

They are on horizontal or somewhat horizontal surfaces...a friend used Nu Finish and didn't have the stains. After a week the rain had surprisingly removed some of the stains but some still remain.

[Russell]

This sounds like the tree pollen that is turning everything yellow around here. Rain does wash most of it away.

[jleonard]

2 words:
Slimy Grimy

[joe.baar]

Re: Cape Codder's April 6th post mentioning K-Mart's "The Works" as containing oxalic acid which will remove yellow or rust stains. I purchased a $2.09 quart bottle yesterday and it seems the formula is a little different out here in the Pacific Northwest. The ingredients are listed as "Hydrogen Chloride 16%" and the remaining 84% is inert. If I understand chemistry correctly this means the stuff I got is 16% hydrochloric acid, which I believe is about as strong as your standard muriatic acid etcher for concrete and metals. This bottle is advertised to remove "rust, lime, scale and hard water stains" and it says it will also kill household bacteria (duhhh). In an effort to find a product at K-Mart containing oxalic acid I examined several other cleaners there and found CLR also contains none, but its active ingredient is different, similar to bleach I think.

My neighbor's 2660 Mercury has yellow stains below the boot topping that were not susceptible to acetone, lacquer thinner or Goof-Off and I plan to try The Works on it this afternoon (Pacific Daylight Time), after which I will give AOG a further report.

I'm aware the formulation of The Works might damage the gel coat and plan to rinse it off immediately and thoroughly, especially if it doesn't give a fast result.
============================
Thursday afternoon:
I put a quarter-sized dollop of The Works on a rag and rubbed it gently on the stained area. 10 seconds later it was white. I rinsed the area three times and dried it. I haven't done a magnified examination for damage but none is evident to the unaided eye. Boatmon standard before-and-after photos are attached. I would use MUCH less on a painted surface, or dilute it a lot with water.