KBS "Gold Standard" Tank Sealer

The phos acid patina is very thin and fine when not exposed to moisture or painted over but don't expect if to last against normal moisture in gas let alone the extra corrosive help of short carbon chain with reactive negative charged hydroxyl group hanging off the end wanting to be rid of its extra e- so forcing it on + metal ions so they don't care to hang out with their buddies anymore.

I'm pickling inside frame with strontium zinc phosphosilicate via a product that's rather thicker and tougher than phos acid mild etching coating.

Wooden tanks-casks can hold gas and booze forever more...