Compressor tank cleaning

"Old." I'll tell ya Rob, I'd seriously and I do mean, consider hydrotesting that thing. A guy like you can do it yourself. You may know, the entire idea of a hydrotest is that if you burst the thing, water won't cause a huge explosion.........just a mess

Fill it clear full of water and devise a way to pressure it up. You could even use CO2 for "that last cup" so long as you get it full. Tank should be tagged as to what specs it meets.

I've considered.......LOL if I ever buy a new one.......of "POR 15 coating" the bottom of the tank.

Nope wasn't mine LOL