Surface Rust Removal Autobody

As a follow-up to an earlier post about removing old paint from my project truck. I am removing the old paint and finding surface rust. I have come to realize that there are different types of rust and removing it can be easy or a real challenge. I remove the paint with a wire wheel on an angle grinder. I like the flat wire wheels for this not the cup type. This does a good job of paint removal but the surface rust laughs at it. This is my second truck restoration and like the first one, the top of the cab has a scale of very hard surface rust. I use an angle grinder with 80 grit flap disk to start attacking the rust but you need to be careful because it will also start to remove metal around the rust. I end up removing a lot of the rust with a small hard rubber sanding block and 40 grit. I can focus the pressure and sanding force on the problem areas and not remove a lot of good metal. This is slow hard work. Once I have the rust removed there are thousands of tiny pits the size of a pin head that I hit with phosphoric acid rust converter. Then seal everything up with epoxy primer.

The only other method I know to do this is sand blasting. I have a small pot sand blaster that works the heck out of my compressor. To be honest I prefer the hand sanding method to sand blasting. Sand blasting with a small home setup is not fun in any way. Do you guys have any other methods to do this? I know what I do works. I did my first truck this way and 8 years latter there are no issues. The other option is to send it out for sand blasting. I have priced this in the past and I think to have my cab blasted and primed would run $700 to $800. That is just the cab. No doors or fenders.

The way that you have been doing it is exactly how I do it. I have found a lot of little spots of surface rust under the paint on a '57 tractor and a '67 car. A little pot blaster should be safe for the sheet metal where a big industrial unit could distort it. I usually use the acid even after sand blasting because you just can't be sure that all of the rust is out of the pits.

orbital sander GOOD quality 80grit is my choice. If need be in some spots, hit it with the little sandblaster. Follow with Picklex 20. It's expensive, but a little covers a lot of area. That will prep any micro rust spots for primer and keep dry metal from further flash rust for a long time, years in my case.

If you use any acid product, be sure to check your primer's usage instructions. Most epoxies do not like acid. I use Kirker as it is OK over acid and is the most econnomical I've found. Under 150 for two sprayable gallons. 1:1 mix and not induction time. And, it works.

Top it with your choice of 2k primers.

Sounds like you are doing good. Once you get the paint out of the way the rust can be treated. The epoxy primer should prevent the rust from coming back.

I use Omni epoxy primer. It works fine with acid. I skim coat the body filler over the top of the epoxy while the epoxy is still open. Then I wait a few weeks to sand and feather the edges. Sanding epoxy primer before it is fully cured is like sanding bubble gum. After a few weeks I can sand it. Once the body filler is finished I scratch up the epoxy that doesn't have any filler with 150 grit, shoot another coat of epoxy followed by the high build primer. Then block sand it and final paint.

I have been using a detail sander with 60 and 80 grit on some tractor sheet metal. Really cuts the top of the rust open allowing the pickelex, must for rust, or your choice of phosphoric acid to get in the remaining pits. Saves my elbows and hands from all that sanding with a block. Sounds like you've found a system that works for you, thank you for sharing. gobble