I have taken the tanks out of my trucks, had them boiled clean at a radiator shop, and pressure tested. Each time I buy new tanks. It seems like this whole process with any of the tank sealer is close to the cost of a new tank.
I go with new tanks over recoated used leaky tanks. If you don't coat them right the stuff comes/flakes off and you will have a problem when you least want it.
You can always cut a hole in the old tank, mount it on the wall and use it for a rag container or nostalgic shelf unit.
My 2 centavos.
