cleaning a scumline

[fastal]

I dock my boat in a brackish river up here in the northeast. During the year a pretty good scumline/stain appears above the bottom paint. Some have suggested acetone to remove this others have said it is too harsh. Any suggestions?

 

[Lainie J]

Scum line

Mary Kate On and Off, come right off. Just use on scum line, take off all wax.

 

[cdwood]

MK's on/off is the ticket but be sure to follow directions, very strong stuff. Outdoor use only, ideally while your still in the water.

 

[Jas]

Here in the Chesapeake we run into the same issue. I bought my 1997 new to me Gulfstream with the paint and the scum line struck exactly at the water line, which I think is a mistake. This summer I raised it about two inches. It looks much better and although there are still some small brackish stains, I’ve removed about 80 to 90 of them.

 

[georgemjr]

FSR Fiberglass Stain Remover. Think of it as the blue-colored gel version of Mary Kate On/Off. I use a paint brush to brush it on. The benefits over on/off is that it isn't toxic to breath in like the MK and it doesn't burn your cuticles/cuts on your hand. Both work great. When I use MK, I put it in a spray bottle and spray it on. If you leave it in the spray bottle, the sprayer will not work next time you try to use it, so you must put remaining product back into original container and clean out the sprayer.

 

[Strikezone]

For a non-caustic solution you might try Slimy Grimy. This used to be available at Boater's World but not sure who may carry it now. It can be purchased directly through the manufacturer however.

 

[ksgoldman]

If you go to the Defender Industries or West Marine websites and do a search on hull cleaner, there are a number of brands that all do basically the same thing. They are a mild acid (or non-acid versions) that works really well to clean off the scum line. I keep my boat on the Sakonnet River in Rhode Island (which is actually a saltwater strait) and I get a terrible scum line. Using hull cleaner (I use either Sea Safe or Thetford).

Wear gloves and eye protection - this stuff is caustic. I do it while the boat is in the water and have to warn you that it will discolor your bottom paint if you aren't careful. I also made the mistake of doing it from my dinghy and now have some nice stains on my inflatable.

I also accidentally lost part of my boot stripe to hull cleaner (as you have to leave it on for a few minutes before rinsing it off).

Good luck.

 

[sfc2113]

Barkeepers friend

 

[busterblue]

wood cleaner

Oxalic (sp?) acid, it's the active ingrediaent in On/Off but you can get it at Lowes etc. for $15/gal. Make sure you wet any metal it may come in contact with and wash down if you spill.