I'm getting closer to painting my '53 F-100. I'm using PPG DP epoxy primer and DAR acrylic enamel. I'm squirting some compatible 2k surface primer before the topcoat to deal with minor surface issues. I've asked some questions on the paint sub-forum at FTE, but I thought I'd poll folks here, in as much as most of us are dealing with the kind of rust that comes along with 60 year old vehicles. My question at the moment is: should rust that has developed between panels that have been spot welded together (the roof skin to the back of the cab, for example) be treated some way? I have cleaned the cab to bare metal. I can see that over the years water has got in between the metal panels and caused some rust. It's not the kind of ugly through-rust that I have been cutting out and and patching. But there is still some there. There is no way to completely clean that thin line of rust that I can see. Does PickleX 20 penetrate into these cracks? Or other rust converters? I know I have to keep away from any acid products, if I want the primer to adhere properly.Or, am I worrying about nothing...maybe the epoxy primer will just cover it up and that's that. I know that before painting I'm supposed to wash it with soap and water, then go over it with a degreaser. I worry that the rust in the cracks will have absorbed enough water when I clean it to create problems down the road. How is this all dealt with? Thanks.

 

I personally would never wash metal down with soap and water as it's just asking for rust to happen .
I always use a pre paint wax and grease remover which is wiped on with clean rag .
You would be surprised what comes off clean looking metal .

 

Theres not much you can do short of taking it apart. I would avoid using acid or water prior to paint. Clean as best you can, prime, and then seam seal as needed.

 

Rustoleum rust converter is not an acid product, comes as a liquid you apply with a pad or in a rattle can, and is designed to be painted over after 24 hrs curing. does not require flushing. Be sure to wear gloves when using, it will convert the iron compounds in your skin permanently black as well, it does not wash off the skin. I have had excellent results with it when following the directions. It is available in big box DIY stores that carry Rustoleum products. look for the liquid with the painting chemicals in a squeeze bottle with an applicator pad attached to the side. It's not cheap, but it goes a long way when used properly. It is not a paint and has no affect on clean metal.

 

You are justified in your concern about rust between panels. There are many products out there that will seep into these seams and encapsulate the rust within. I use a product called Chassis Saver...there is also POR15, Rust Bullet, Zero Rust and many others. Each has a selling point but most work equally well for the task at hand. I like Chassis Saver because it is about half the price of POR15 and seems to work just as well. Here are a few pics of my cab after I applied Chassis Saver on the inside seams...I was very surprised to see it seep out through the roof seams, I thought the seams were very tight. I also use it on the seams at the back of the cab along the floor...this area gets a lot of moisture with no real place to drain off.