The Stovebolt Site Forums The Shop Area Paint and Body Shop Patching sheet metal and stopping rust

I am about to start tackling the job of cutting out and patching the rusted panels on my truck cab and I was wondering what you guys do about flash rust. The area I`m working in is not totally moisture free but it doesn`t get wet either. I don`t really want to completely strip all of the old paint at once, so I was thinking about maybe just cleaning the part of the cab I am working on and then when I get done with that spray it with aerosol epoxy primer, then when I`m totally finished, remove all of the spray on primer and old paint that`s left either by media blasting or manually removing it. Has this worked ok for some f you in the past?
Thanks, Mike

Do you mean like THIS ?

I did this cab corner in September and it looks exactly like that today. I keep the truck inside my garage & like you said, it doesn't get wet, but there is the Florida humidity and it has not formed any rust at all.
I did replace my roof with a used roof from another truck, and that did flash rust. I just used a wire wheel on my drill to remove it and sprayed Eastwood rust encapsulator on it.

Thanks, that`s about what I was looking for.
I think I will patch mine similar and then if rust starts to form I might put something temporary over it.
Good pictures by the way.
Mike

Mike:
You might want to check into using Phosphoric acid. You can purchase it from paint stores as well as home depot. I use it in a spray bottle on bare metal, scuff it in with a scotch brite, then wipe off any residue with a paper towel. When you are ready to epoxy prime, you scuff and clean with wax and grease remover then it is ready to spray. The phosphoric acid etches the metal and converts and rust to iron oxide so that it doesn't rust as long as it is out of the weather and is not getting wet. The only caveat is that you can't use a second product with phosphoric acid over it (i.e. no etch primer and no epoxy that contains phosphoric acid (Valspar and HOK are two that do. I use Kirker Enduro that doesn't)). Phosphoric acid is sold under many brand names such as Ospho, Chem Prime, Picklex, etc.

I hope this is helpful.

regards,
Steve
New Orleans

Converts iron oxide (rust) to iron phosphate. Good stuff.

Thanks guys, I had seen a guy using that Ospho on Youtube and it looked like it worked pretty good.
Mike

why not just paint it with a quality primer that you will eventually finish the truck off with?

Well, I`m going to be working on small sections at a time and I don`t really want to break out the HVLP everytime I want to prime one little part of finished body work, so I would like to spray it all at once when I get all of the metal work done on it. That brings up another item. This is all a moot point if I decide to get it media blasted, because then it won`t have any paint on it anyway. I used some aircraft paint remover the other day and it worked pretty good, butI don`t know how hard it will be to get into the small crevices etc that are on the cab.
Mike

Another problem with priming the metal is that unless its topcoated within the window, its going to need to be scuffed up.
I have some stuff now that way and I am not looking forward to having to scuff up every knook and cranny.

Ospho

I bought some locally, forget what I paid, but have not used it yet. It is alot less expensive than Picklex or the paint mfg's metal treatments and I bet its all pretty much the same stuff.