Cleaning the hull

NYSail

.
Jan 6, 2006
3,136
Beneteau 423 Mt. Sinai, NY
Hello all
So I’ve had a very busy sailing season and the boat is showing it. The waterline and a little above has a lot of brown salt residue. What do people find is the best product to remove this without massive scrubbing like I typically do.

Thanks in advance

Greg
 
Nov 12, 2009
268
J/ 32 NCYC, Western Lake Erie
We've had good luck removing tannin stains from the ICW using a hydrochloric based toilet bowl cleaner. The thicker, gel-type cleaner is easier to apply. Apply to a couple feet of the stained area, wait a couple of minutes, and then rinse off with water. After you do a couple of areas you'll figure out how big an area you can do, and how long you need to wait before rinsing. Virtually no scrubbing should be necessary.
 
Jul 12, 2011
1,165
Leopard 40 Jupiter, Florida
Tannins and metals (iron, for example) react well to acids, so I'd pick Marykate On-and-Off, available from Waste Marine, Amazon, Defender, or even Walmart. Get the gel version so it sticks for a little, and remember to use proper PPE - gloves and eye protection at least. This stuff is probably not good for the environment … so don't get caught. If you have a dinghy, this work is much easier from up close rather than leaning over the rail four feet.
 
May 12, 2004
1,505
Hunter Cherubini 30 New Port Richey
We've had good luck removing tannin stains from the ICW using a hydrochloric based toilet bowl cleaner.
Be careful it's not a blue solution. It will remove the stain but leave a blue hued hull that requires lots of elbow grease to remove. No need to ask me how I know. :facepalm:
 
Jan 11, 2014
12,725
Sabre 362 113 Fair Haven, NY
We've had good luck removing tannin stains from the ICW using a hydrochloric based toilet bowl cleaner. The thicker, gel-type cleaner is easier to apply. Apply to a couple feet of the stained area, wait a couple of minutes, and then rinse off with water. After you do a couple of areas you'll figure out how big an area you can do, and how long you need to wait before rinsing. Virtually no scrubbing should be necessary.
It is considerably cheaper to just buy a gallon of Muriatic Acid at the hardware store, dilute by 50% with water and apply with a cheap disposable chip brush. Rinse thoroughly with fresh water.

Muriatic acid is 30% Hydrochloric acid and is used to clean concrete and masonry. Hydrochloric acid is also known stomach acid at considerably more dilute solution.
 
Nov 12, 2009
268
J/ 32 NCYC, Western Lake Erie
It is considerably cheaper to just buy a gallon of Muriatic Acid at the hardware store, dilute by 50% with water and apply with a cheap disposable chip brush. Rinse thoroughly with fresh water.

Muriatic acid is 30% Hydrochloric acid and is used to clean concrete and masonry. Hydrochloric acid is also known stomach acid at considerably more dilute solution.
I'm not sure how much a gallon of muriatic acid costs, but we buy toilet bowl cleaner at the dollar store and it lasts several years for fresh water stains in the Great Lakes.
 
Jan 24, 2017
670
Hunter 34 Toms River Nj
bar keepers friend works great about $3 at most supper markets and significantly less then marrykate on off hull cleaner
 
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Jan 7, 2011
5,456
Oday 322 East Chicago, IN
Bar Keepers Friend, Home
View attachment 208821

or OXALIC ACID 99.6% 2 Lb. Deck, Crystals, Metal Cleaning- Rust Removal from Amazon
But it is very abrasive.

I use it on my deck non-skid, and it cleans tough stains and whitens the decks.
But I wouldn’t use it flat gel coat.

If you are cleaning below the waterline, it should be ok.

Last spring, I used some Soft Scrub on the gel coat at the waterline pretty successfully.

Greg
 

NYSail

.
Jan 6, 2006
3,136
Beneteau 423 Mt. Sinai, NY
Thanks all…… yes I have read discussions on the use of acids successfully. We do use on/off on the boot stripe. This season it’s just up the hull a bit. I bought some FSR and will report back with the results. Boat gets hauled Wednesday for a day on land to clean the hull and inspect zincs.
Thanks again
Greg
 
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