fresh water tank leak

[joelselman]

I appear to have a leak from a corner of my STAINLESS STEEL fresh water tank. I thought stainless wasn't supposed to deteriorate. Possibly bad weld????

[jack14r]

Joel,Liberty might warranty that if it is the tank.

[Jon Wehrenberg]

Joel,

The tank on my 87 Liberty had leaks an when I found them the floor had a rotted section. I repaired the floor and by pressurizing the tank I found the leaks with soapy water. The more I welded the leaks the more leaks I got, so I just re-welded the entire tank using stainless wire and a mig welder. I think the reason for the leaks was the joints were ground and polished.

Pull it out and a good welder will repair it in 30 minutes by rewelding all welded joints. Cheaper than a trip to FL or IL.

[joelselman]

Thanks Jon, that's what I suspected.

I didn't buy the extended lifetime warranty from Liberty. I think the price was $599,999.00. Definitely cheaper than a trip to Florida, but if I HAVE to go to Florida, I can usually find a few fun things to do!

[BenC]

I appear to have a leak from a corner of my STAINLESS STEEL fresh water tank. I thought stainless wasn't supposed to deteriorate. Possibly bad weld????

The problem with welds in stainless steel is that by definition, you change the crystalline structure of the metal and thus the properties of the metal by doing the welding. Over the years, I have seen many stainless tanks, both in Liberty and Vogue Prevost conversions, rust and eventually leak at the welds and joints. You can even take a camera and look down inside one and see rust spots where the baffles are welded to the side walls and corners are welded together.

[Jon Wehrenberg]

In a previous life our factory in Jamestown NY made tens of thousands of welded tanks eah year. We shipped them by the semi load. Each year we failed to make a leak free product about 2 or 3 times, mostly due to a bad weld that got by the tester, but occasionally because the tank had the wrong fittings.

Welding is an exact science and it starts with a design of the product which includes consideration of the weld. Because of the nature of our holding tanks, we have to consider they are going from full to empty so they do see varying stresses, but worse....they are subject to a range of vibrations which eventually can cause anything to fail.

It is my opinion that before the holding tank tops are welded in place the welded joints should be welded on both sides (inside and out) and that the joints should not be ground and polished. That should produce tanks which are leak free their entire life. But if one does leak, I found the easiest way to cure the problem rather than a small bead of weld here and there was to just reweld the entire tank. If the weld at the baffles broke there is nothing that can be done unless someone is willing to cut a sufficiently large opening in the top of the tank to access the baffle ends for rewelding, and to either bolt a gasketed cover in place or weld a new top in place.

The presence of iron in the water is likely to create the rust Ben describes. Stainless steel, even when it is not welded is prone to rusting if it comes in contact with ferrous tools or materials. Our fellow POG member Harry Hoppe stressed the importance of not allowing steel or iron tools to come in contact with stainess that was being repaired or repolished because the result would be the formkation of rust.