Re: [SilverStreak] changing out the water tank

[<waymark1@xxxxxxxx>]

"Glass lined" is a coating of porcelain enamel that is sprayed on the
inside of the steel tank while it is heated orange-red. The powdered
glass melts on the inside of the tank, providing a watertight coating.
This is the same process as is used in water heaters.
Unfortunately as the years go by tiny defects in the coating, especially
around fittings, permit corrosion to get under the porcelain, causing
rust. It's not as bad as in a water heater as only cold water is in the
tank, and in most of our RVs the tank is empty most of the time. So
instead of beginning to rust after 5 or so years like a water heater it
is 20 or more years before significant rusting takes place.
Once the tank begins rusting it will be only a few years until it rusts
through in a spot. It can't be stopped by any practical means as the
sealers that will work are not what you would want your drinking water
exposed to.
An anode rod as is used in water heaters would help, but I don't think
these fresh water tanks have one.
Al