Corroded Water Tank

[weephee]

Just one more question for this week. I removed my water tank from the boat so that I could clean and paint under it. The tank sits on a wooden supports. When I inspected the tank I found it badly corroded and full of holes on the bottom. The tank is made from aluminum and has a ground wire attached to it. Any ideas as to why it would be full of holes. I'm planning on having one made out of stainless steel. Will that also corrode.

[RichH]

Aluminum tank - normal chlorine in your water corroded the tank. You also probably found a lot of 'white sand' (aluminum chloridte) in the bottom. Aluminum makes LOUSEY water tanks because of the attack by chlorine.

Stainless steel tanks should have a minimum of welds, the welds ground smooth, .... then the tank should be passivated. Stainless 316 is the material of choice for water tanks. Polished stainless (internals) is best.