Adding electric heat element to gas water heater

Boon Docker wrote:
Teflon or plumbers tape is used to make a good seal. It will not slow corrosion.

That's right, put Teflon tape on some threads, insert the threaded connection and then remove. Look at the condition of the Teflon, what there is left of it.

Also I suspect that the heating element need to make an electrical connection via the threaded nipple.

The magnesium anode is the best plan but be warned it may need to be replaced in a short time period, months maybe not years.