Thread: How am I going to prep this body for paint?

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Just be sure you do not bondo over areas that have not been neutralized somehow with an acid product. Rust is an ongoing process. Brushing it off, but leaving little pits with orange or brown rust in them will not stop it. It will just rust again under the body filler.

Perhaps an etching primer would be best, then use a compatible body filler over the top of it.

Another way I have used with success is to sand as much off as possible, treat with metal prep keeping it wet for 3 minutes, let dry, then resand and bondo. The point is that the phosphoric acid in metal prep changes rust (iron oxide) to iron phosphate (gray color), and you will not have the rust coming back.

Good luck. It's worth the effort!

Originally Posted by HOTRODPAINT

Just be sure you do not bondo over areas that have not been neutralized somehow. Rust is an ongoing process. Brushing it off, but leaving little pits with orange or brown rust in them will not stop it.

Perhaps an etching primer would be best, then use a compatible body filler over the top of it.

I understand rust doesnt stop but doesnt the phosporic acid convert the rust to black oxide and it is no longer rust?