Rust Repair

[Davidrad]

Hello All,

Like most of you when you started I'm comfortable with mechanical and less so with body work. My recently acquired 70 Swinger is in great shape but a few spots of scaling rust has happened on the body. I've been given two different pieces of advice.
1st - To sand down to bare shinny metal and primer. Some of the scale is pretty deep and requires a lot of sanding which can create too much heat. Most of this rust is on the c pillar where the roof meets the rear quarter panel. My Swinger has filler in this spot.
2nd - To sand just a bit to score it and use a POR-15 type rust preventer. This method keeps more metal and more structural integrity.

What are your thoughts?

 

[turtleheadjoe]

I'm definitely not a body man, but when it comes to my duster I make sure to get all the rust out of the area I'm working on. I cut/sand an area quite a bit larger than I need to just to make sure. I hate body work, I don't want to do it again in a few years.

I'd take my time and sand it all out, but I'll bet others disagree with me because that seems to be how things go.

 

[BillGrissom]

I hate painting more than body work since something always goes wrong. If you can't sand away the rust pits, there are some products that eat away rust (Evapo-Rust), but you usually must dip the part in them, so see if anyone has had luck covering w/ a soaked rag and plastic. Many rust-converter products that will turn it to a hard black phosphate (?) and might work in the pits. If you sand too much, the metal will get too thin, and some pits may even go thru. A classic fix is to fill w/ lead, but wonder if that works on rust pits. Regardless, you should remove interior to get at the back side to treat that. Many rust-thrus are from the inside since they barely painted the metal there, like not at all at the tops of the doors. Any metal you weld in should be sprayed with high-zinc if it can't be painted later. You can use Home Depot cans or special "weld-thru primer". The main goal is to seal so moisture can't get at the steel. Rust doesn't really spread like cancer, it is just flaky so paint can't bond well. In theory it can be sealed and stopped.