repurpose water heater tank?

jumper

Anyone here plugged old leaking water heater to use for thermal storage?
In closed system maybe corrosion does not progress?

hot_rod

Once the glass coating is broken, I doubt you could keep it from leaking, the metal has been compromised

Larry Weingarten

Hi, Agree with Hot Rod. Better to find one that has a failed control or some other reason for replacement... then keep a good anode in it!

Yours, Larry

jumper

hot_rod said:

Once the glass coating is broken, I doubt you could keep it from leaking, the metal has been compromised

Does the coating break? Does aggressive fresh water eat through it? Or is there a flaw that allows water to eventually rust through?

For thermal storage water does not need to be potable. Can water be "deactivated" to inhibit rusting?

Larry Weingarten

Hi, The glass lining is very much like the glazing on a ceramic plate or pot. It's thin and brittle. It can crack with thermal expansion or abuse, It can get worn away by heat. Commonly, when covered by sediment in a gas fired heater, the glass lining vanished because of the heat. With small holes or cracks in it, the anode can keep up and protect the steel. But no anode can reverse rust damage, which is why I don't try to work with thank that have leaked unless it's to make a planter or something. Oxygen free water will do a lot less to damage bare steel, though chlorides, or bits of other metals in the water could still cause problems.

Yours, Larry

hot_rod

a crack in the coating allow water to rust the steel tank. so the metal at the leak point is thin, may not be able to be patched.

Also if the insulation has been wet, the tank corrodes from the outside. Its not so easy to remove the jacket, strip the tank, repair and reassemble. some of the tanks are spray foamed, making insulation removal a PITA.
How old is the tank? 5 years or 20 years old?

ethicalpaul

Get the Rheem Marathon plastic one and it will outlast us all