"RoyJ" wrote in message
nk.net...
Are thinking about a hot water HEATER tank or a hot water BOILER tank?
They are quite different critters.

I certainly would not consider a used one for the project. They usually
have enough accumulated corrosion to make them pretty weak.

Keep in mind that a failure in a hot water tank results in a small
pressure leak and then just drips. The compressed air tank has a large
amount of stored energy, they can fail catastrophically.

I'd be inclined to agree.

Harold