The Stovebolt Site Forums The Shop Area Paint and Body Shop Epoxy Primer over really old paint & primer ?

Excellent video Rick, thanks for posting. That SPI epoxy is some tough stuff. Also good testament to Evercoat Rage Gold filler. I do wonder if the first panel had been a very rusty metal like our trucks would he had a different result.

I wish we had a chemist on here to explain the different chemical reactions. My premise is that if all the acid reacts with rust, there is no acid left so it should not cause a problem. Although I've never had a problem on the farm, with tractor paint as you are fond of saying, I think issues occur when there is excess acid that doesn't react with rust and prevents epoxy from sticking. Guessing you will always have excess Non reacted acid in joints, corners, etc. I've got unpainted metal panels that have been treated with ospho (Gem rust killer is what I use), and not painted and they look exactly the same as the day I sandblasted and treated them...and it's been a couple years. To prove it to myself, the next time I fire up the sandblaster, I'm going to treat the blasted metal with ospho then give it a good wash with water and sit it beside the other non washed version to see how they age.