Stubborn stains on bottom of boat

[skategoat]

I tried toilet cleaner and a pressure washer but it didn't do a lot of good. Any tips on what else to try for the below-waterline stains? Bleach?

And how do you clean areas covered up by the trailer bunks? Do you temporarily jack the boat off the bunks? Any advice on doing that without damaging the hull?

 

[tashasdaddy]

Re: Stubborn stains on bottom of boat

where the picture?

 

[skategoat]

Re: Stubborn stains on bottom of boat

Weird. The image shows up in Preview but not when I save the message. I attached it instead of linking to it.

 

[tashasdaddy]

Re: Stubborn stains on bottom of boat

it may be permanent, comet cleaner and elbow grease. marykate cleaners may clean it up. suggest bottom paint.

 

[AZSenza]

Re: Stubborn stains on bottom of boat

Dude, you wont get very far without a prop

Ya what he said! It looks like its thru the gelcoat from the pics though. Gelcoat is somewhat porous, you gotta keep it clean and wax on it.

 

[gcboat]

Re: Stubborn stains on bottom of boat

If this stuff doesn't remove it nothing will :http://www.iboats.com/MaryKate_On_O...17550651--**********.044919961--view_id.48558
Please - READ THE DIRECTIONS !!!!!!!!!!!

 

[SS MAYFLOAT]

Re: Stubborn stains on bottom of boat

Wouldn't hurt to try CLR on in it. I've had some rust stains in my gel coat. Couldn't get them out. Put CLR on a paper towel and let it set. The next day the rust stains was gone. It didn't work right away, but it did remove the rust stains.

 

[cbavier]

Re: Stubborn stains on bottom of boat

There are a couple things besides the CLR or Marykate you can try.
Starbrite makes "Hull Cleaner" It's an acid wash designed mainly to remove oxidation from Fiberglass.

Or you can get a commercial buffer and on slow speed increasing your speed as you go use 3M Marine Color/Gloss Restorer. If you choose this route be sure and follow the instructions on the bottle exactly as written. It's about $30 a 16oz bottle. Available at West Marine,maybe your local marine dealer.


Chuck's Fiberglass & Color Restore

 

[79Merc80]

Re: Stubborn stains on bottom of boat

I had a simular stain on the bottom of my parents boat from the red shorline at Trinity Lake in Norhten CA. I tried everything, including bleach and comet. The thing that removed it was Super Clean (Can get it at Wall Mart). What little was left was taken off by Liquid Lustre wax (Can get it on line).

Craig

 

[nlain]

Re: Stubborn stains on bottom of boat

Be sure to use rubber gloves with all of the products mentioned, they are after acid. I use a product called Whink, in the grocery store with the cleaning products, I also use CLR. Two days, one night, in the water where I am and I have the bathtub ring on my boat, have to clean it off every time it goes in the water. I flush the engine first, then start cleaning the boat, it usually takes longer to get the ring off than to clean the rest of the boat. You are not going to just put one application of anything on and clean it off, you will have to do it over and over and over until clean. The longer it sets and dries in I think the worse it is to clean.

 

[haskindm]

Re: Stubborn stains on bottom of boat

Most marine stores sell a product called "FSR" (Fiberglass Stain Remover). It is a gel, so it stays where you put it. It is very acidic and will often make stains that have resisted other cleaners disappear like magic. May be worth a try. Make sure you do not get it on your galvanized trailer, it leaves black stains on the galvanized metal. Don't ask me how I know this....

 

[Chevysolid]

Re: Stubborn stains on bottom of boat

Slimy Grimy worked well for me... non acidic, even got it in my eye and there was no burn or odor.... bit expensive but worked awesome...

see here ---> http://www.youtube.com/watch?v=3snjD4Wz5dQ

 

[KLINDWW]

Re: Stubborn stains on bottom of boat

I?m with cbavier, the Starbright Hull cleaner works like magic on those kind of stains. Just take a sponge and wipe it on and work down the hull, when you get about half way down the hull you will look back and the hull where you have wiped the hull cleaner on will be white. I boat a lot in Galveston Bay (Not the clearest bay in the country) and these kind of stains are a constant problem down here.

 

[Cptkid570]

Re: Stubborn stains on bottom of boat

I have absolutely no idea what it will do to your gelcoat, but muratic acid should take it off. I've used it on mine and and it took off similar stains. Once done, I'd make sure I'd wax it real good to ensure that it doesn't get back on (as said above, fiberglass is porous).

Anyway, once again, I don't know if it hurts your gelcoat or not, but should work and is available at hardware stores.

 

[lucky51]

Re: Stubborn stains on bottom of boat

I to have used the Muratic (sp) acid. I cut it 50/50 with water and did not leave it on more than 30 sec. at a time. A soft brush took the stains off. Then a good coat of wax.


Be careful and it has worked fine for me.

 

[Cptkid570]

Re: Stubborn stains on bottom of boat

If you do go the muratic acid route, make sure you wear rubber gloves and don't breathe it in either...

Let us know what you end up using and what works for you.

 

[skategoat]

Re: Stubborn stains on bottom of boat

Thanks for the replies. I have used muriatic acid in my swimming pool and it is nasty stuff. I will try some 50/50 with water. I'll also try CLR and some of the other suggestions and report back. If course, this will all have to wait a couple of months. We are getting hit with another snow storm.

 

[gstanton]

Re: Stubborn stains on bottom of boat

I too love Slimey Grimey. It is really Oxalic acid and is melting algae... yes, that brown stuff is algae!
Not to hurt the Slimey folks, but you can find Oxalic acid at West Marine/Boaters world etc... for less.

You do still have to brush the hull, but mostly to get the oil scum and other crap off.

 

[mthieme]

Re: Stubborn stains on bottom of boat

My poor old hull is always dingy.
I use muratic acid in the spring.