found this rust under my gas tank.. looks like gm decided it wasnt important enough to undercoat. this is the only rust i have on my car and it almost looks like weld splatters. anyway i need to know were to start. can i just sand it down to bare metal rattle prime and paint over it with acrylic enamel?

You must live in the south or west, and I envy you. That doesn't even qualify as "rust" up here!

Sand it, wire wheel it, wire brush it, whatever method you prefer to knock off the scaly/loose stuff. Then clean the area with some degreaser, apply a couple coats of Ospho acid, and after that dries, apply a coat or two of Master Series silver and the rust will never return.

Thats not rust!!!!

Yea I live in ny but actualy got this car in florida. So its zero rust except for this . im going to wire wheel it tommorow hopefully i can get it all ready to prep and coat. thanks!

Hey, I have a 85 berlinetta too anyway, what I do for rust, is this:
1. Wire brush hardcore
2. Sand hardcore
3. 3M pad hardcore
4. POR15 all over it
5. Sand when dry
6. Prime
7. Paint

A little work and you will have it looking like mine

nice! por15??

Product is SEM Rust-Shield (Rust and Corrrsion Control Coating). It sprays on really nice but this is the first time I have used it so no long term results to comment on.

Ok guys i went out and worked on it a little. Do you think its ready for the por15 or should i sand/grind it down some more? Ive heard por15 actualy works better if theres a little rust to bond to. But im kinda leary of leaving this much behind ...the metal would have to be ground to get rid of the rest and this metal is like recycled beer cans its so thin. Its weird because to my eye it looks like black spots yet the camera pics up orange... weird

sand more, the primer it with a Rust and Corrrsion Control Coating , rust is like cancer it still can come back,


i get that alot. i work for a chevy dealership painting cars, so protect it