Adding electric heat element to gas water heater

There is one kit that includes a magnesium rod to protect the aluminium.

Then pull the element and see if you notice any corrosion on the threads. It none then screw the element back in and check again in another 3 months.

Unfortunately the corrosion will occur on the aluminum side not the brass side. Aluminum will form the anode. I'd expect corrosion to occur at the contact zone between the brass and aluminum.

If the tank has a sacrificial anode, which it probably does not in a propane only heater, that may corrode instead of the aluminum.

Yeah, I've already ordered a kit and will likely take that approach.

Thanks All!

I may be wrong but I don't think galvanic corrosion happens very fast.
I would probably buy a electric element and screw it into the tank. Then after 3 months turn off the water heater and let the tank cool. Then pull the element and see if you notice any corrosion on the threads. It none then screw the element back in and check again in another 3 months.
After your 6 months remove the element and put the plastic drain plug back in.

On one of my gas only water heaters I added a hot ROD I think it was called.
worked but a bit slow.
bumpy

Not with the kits, but yes Aluminum and Brass will set up a galvanic cell. Putting a insulating gasket in between the brass fitting and the tank may prevent the corrosion. A piece of teflon or rubber would work.