Rust in water tanks

[dmksails]

The inside of my water tanks are showing rust on the seams. Do I need to worry about this and if so, how do I clean it?

[Sailmonkey]

I'll assume your tanks are stainless.

There's really nothing you can do about it. Just clean your tanks as you normally would to contain potable water and carry on.

[a64pilot]

Rust is of course usually iron oxide.
To try to make your tanks last as long as possible I would keep from adding oxidizing agents (bleach for instance).
I have aluminum tanks, and they are worse than SS, I filter all my water through a carbon block filter to remove chlorine and as long as I don't let the water sit too long, don't have a problem with it.

[Cheechako]

It's not surprising. The welded seams have been heated to the point where they tend to rust. It's nature of the beast with welded stainless... unless the tank is solution heat treated after welding... which nobody in the boating industry does and most everyone in the aircraft industry does... :>) Hopefully it's just surface rust and will still last a long time. A worse problem is actually the outside of the tank on the bottom... especially if it's in the bilge under the floor. The support areas stay damp. Wet on stainless is ok, but enclosed wetness with oxygen depletion occurring from lack of fresh air and water makes for rapid corrosion. I had a below floor SS tank fail in 1991 on a 1985 boat .... 6 years. Hole the size of a pencil eraser.

[Dave22q]

If I had a boat with metal tanks an early priority would be to determine the cost of removing and replacing with plastic. If the tanks are standard sizes and not inaccessible the cost may not be prohibitive. Any advantage metal tanks had in the past are long gone.

[DeepFrz]

Don't rush off and start replacing your stainless steel water tanks. They may be good and could last you a long time. What Cheechako says is right on though. Metal tanks need to be mounted correctly or they will deteriorate from the outside in.

[sailcrazy]

We've got 4 s/s water tanks in our 28-yr old boat, and although there was some minor visible rust on the interior seams it did not seem to affect water quality. But now just the last 2 seasons the whole-house water filter seems to clog up with red particulate about every 4-6 weeks, requiring a filter change. The water in the tanks looks clear (via the inspection port, but the internal baffles prevent seeing either end of ea tank), with no suspended matter in the water of any color. But the filters continue to plug up, even when we use a cheap wound 10 micron filter. The water-maker supplied water tastes fine and does not have an oder, but something is plugging the filters. So far we've not found any "fix", and changing the tanks is not an option-they are all 4 under the sole and saloon furniture. But finding some way to stop/curb the rust particulate in the water would be a really good thing.