Water Stains on Hull

[rwidman]

Doug in Bermuda - 6/21/2007 6:56 AM

If you like spending $$$$, go to the marine store & buy something like ON OFF or anything that has 'boat' or 'marine' on the label.

If you are happy with something that simply works go to your home center & get a nice cheap gallon of muriatic acid. Dilute it by more than 50% (makes it even cheaper). Apply it to hull using small paint roller or pad. Instant reaction. Thoroughly rinse off. No scrubbing.

It will also remove rust stains from around deck hardware.

Do NOT get it on a galvanized trailer.

I'm one of those who like spending $$$$ so a few yeards ago I went to the marine center and bought a container of Starbrite Hull Cleaner (it was recommended on a boating forum) to see if it would solve my staining problem. It did and it also had use instructions and safety warnings on the container.

After researching the ingredients listed on the label, I found that it contained primarily oxalic acid. A trip to the home center revealed that Dekswood Deck Cleaner contained the same ingredient and was listed on the label as safe for use on boats, RVs, fiberglass, gelcoat, etc. This is what I use now in place of the "marine" product. I've never read the labels on toilet bowl cleaners or other unconventional products often recommended here, but I would hesitate to apply chemicals not tested and recommended for fiberglass and/or gelcoat on my boat which I consider a big investment. I realize that there are other products listed as safe and effective for cleaning stains on fiberglass and gelcoat and I'm not knocking them.

As for the galvanized trailer, acid will stain the galvanizing (you can't really call it a "finish") but other than the stain, it causes no damage. In a month or two you won't be able to find it because the galvanizing "fades" as it protects. Rinsing afterwards is a good idea but removing and blocking the boat (as has been suggested here in the past) or covering the trailer isn't really necessary. Anyone who owns a galvanized trailer (that includes me) isn't converned about its looks, they are concerned with functionality.

[rwidman]

alan4396 - 6/21/2007 12:51 AM

ACID MAKES WATER TURN TO A RUST STAIN .I HAVE WELL WATER I KNOW

Water can't turn to rust by itself. Is it possible that you also have iron in your well water?

[alan4396]

I LIVE IN FL. MOST PEOPLE THAT HAVE A WELL, HAVE TO HAVE AN IRON FILTER ON THERE WELL .THE RUST AID STATES ITS SAFE FOR FIBERGLASS. I HAVE USED IT FOR 10 YR. OR SO WITH OUT ANY PROBLEMS . ( BROWN STAINS FROM RIVER WATER) MELTS OFF LIKE BUTTER