Any advice on removing boat scum?

[DiSH]

My boat is freshwater only. I was winterizing today and noticed this streak of crud on my hull where the water line would be. I'm not sure what causes this, but it is hard to the touch and almost glued on. Any advice on removing it?

 

[dvx216]

You can always try oven cleaner it does a good job on organic stuff like that.

 

[Jimmy Buoy]

"Iron out" if it's hard water stains.

 

[peterkvs]

Bar Keepers friend. The liquid not the powder.

 

[sea paws]

Marykate On & Off hull cleaner. This stuff is amazing.

 

[DiSH]

Thanks for all the input everybody. Should I worry about any of this stuff being too harsh on the Gelcoat? I want to get this stuff off, but not cause damage in the process.

 

[bbwhitejr]

In the past I have used the Mary Kate product and Iron out. Both worked very well. They did not hurt the gelcoat, but they will discolor an aluminum trailer. Either cover or constantly spray with water.

Bennett

 

[Dieseljeff]

Re-wax after you clean it and all should be ok.

Jeff

 

[Alegria]

Slimey grimey did the trick for me best of all no acid. Just sprayed it on around the water line let it sit and scum just disappeared.

Sent from my XT1575 using Tapatalk

 

[BillK2632]

Mary Kate On-Off is probably the strongest of all those hull cleaners, I would only use it on the worst stuff, wear a mask, it's really bad stuff. I have been using the Attwood hull cleaner (oxolic acid vs hydrocloric acid) it's not nearly as strong as On-Off, but get's the job done. A quart is plenty to clean a 20ft boat - pour it in a spray bottle - spray it on, wait a few min, scrub with soap and rinse. Does not seem to have any affect on decals, but try and keep it away from your galvanized trailer and outdrive - water neutralizes the acid, so keeping the trailer wet while you work helps, but it will do a number on galvanizing. This is not something to use every week, once or twice a year is about it for me - I have found that a quick wipe down while the boat is wet or in the water (before the scum line dries) goes a long way in keeping the boat clean, but once the hull gets the light brown stain, an acid based cleaner is about all that will get it clean again. I follow up the bottom cleaning with a coat of wax - usually spray wax - I know that's a bit anal, but 1) I always see my boat on the lift or a washrack, so I notice the bottom and 2) a coat of wax will help it stay cleaner and make it easier to wipe down.

 

[Lazy Daze]

You get that stuff when there's crap floating on the water while you're waiting to pull the boat out. If you think of it, give the boat a quick wipe down right after you pull out since the stuff will not have hardened, yet. But that's hindsight (or future-sight, depending on how full or empty your glass is, I suppose). For now, you might be able to get it off (at least the hard stuff) by getting it good and wet again (spray it, come back a minute later spray it again, etc, etc) and then rubbing it off with a towel. Or, at least, I've been able to do it that way in the past. If there's any leftover stain (which there probably will be), then use any of the recommendations above. The various acids work great on stains to eliminate the tannins, I'm just not sure how well they will do on the built-up stuff - but I've also never tried the acids on that crusty stuff to say one way or the other.

 

[BryanOnTheBay]

Slimey grimey did the trick for me best of all no acid. Just sprayed it on around the water line let it sit and scum just disappeared.

Sent from my XT1575 using Tapatalk

+1 on the Slimy Grimy. The stuff works miracles. The only drawback is, according to the manufacturer, that it will take wax off.

Bryan

 

[Madifonzo]

+1 for Marykate. Awesome stuff...they have gel form now as well which seems to go further than the liquid version.

 

[NVERL8]

Starbright hull cleaner or slimey grimy

 

[Sprint7TW]

Do you have a pressure washer?
Looking at the picture I think that is all you need. For us who leave the boat in the water we need chemicals. Yours does not look that bad.

 

[sbw1]

Our marina uses HCL or muriatic acid. It does the job with no fuss and no scrubbing. Pool supply companies sell it. Boat stores sell it under the name of Zing. Does not harm gel coat. I keep a jug for touching up the water line at haul out and it makes polishing and waxing a lot easier when the boat is put away for winter storage.