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Repairing a leaking stainless steel freshwater tank on sailboat

May 15, 2009

This regards a 32 year old sailboat with a leaking freshwater tank. This stainless steel tank is imbedded in fiberglass and is covered by a nice wood floor. Below a 10 inch panel in the floor, a 6 inch access port provides the only tank access. Cutting a larger hole in the tank top would necessarily destroy the floor. I have looked inside with mirrors, but have not found a specific leak. But it seems to leak somewhere along a most inferior flange (deduced as this is downhill in the tank.) The 60 gallons empties completely over 2 days. The leak could also be at the aft floor attachment/weld of interior baffles.

Is there a liquid I can pour into this tank that will seal the leak and that is also safe for drinking water? I have considered epoxy, but do not know of a potable type.
Thanks for any help, Rick

Rick Antles
hobbyist - Olympia, Washington, USA

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Hello,

Unless the tank is plumbed or something equally complex, you may just be able to find a bag type liner somewhere. A solution like that may be much easier than trying to find a coating that will A) seal the leak B) not contaminate your fresh water and C) be successful in small enough amounts that you don't have to try to figure out how to empty a full tank of it.

Good luck!

Jim Gorsich
Compton, California, USA
May 28, 2009

Thanks, I've shopped for liners and am considering this. There's a company in Seattle I discovered last week that uses Microseal for just this purpose. Microseal is apparently FDA approved. I might try a sealant before resorting to a liner due to the geometry of the inside of this tanks. Thanks again for your help.

Rick Antles
- Olympia, Washington, USA
June 13, 2009

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You're welcome. I hope you find a solution that works for you.

Good luck!

Jim Gorsich
Compton, California, USA
June 20, 2009