Caswell Tank Sealer - Surface Prep

[radare]

The stuff in that duster can is actually compressed nitrogen. I'm not certain it will do what you want it to, but give it a shot. Be careful when you are doing this too; air and acetone makes a pretty combustible mixture. Keep that tank and any of its byproduct fumes away from ignition sources including static, your cell phone and far-far away from any pilot lights like your water heater.

I'd advise against using a new sealer in the tank. I have yet to see a Seca with a good sealer which lasted. My recommendation would be to clean/remove the existing sealer, clean the tank with Phosphoric Acid and then leave it raw. Many (most) of us have done this without issue.