Need a little advice here

I have started to do some paint and rust removel form my old truck. I stoped by a auto body supply store and talked to the old body shop guy that has th store. Told him I was removing the paint by doing some sand blasting, paint striper, sanding and any other way I can get the 60 year old paint/rust off. I am not going to get all this truck down to bare metal in one day so what can I use to protect the metal that I do get clean that will not be a mess for the body shop/paint guy when that time comes. He recomended I use Sherwin-Williams epoxy self etch primer GBP 988. So I got a few rattle cans of it. I had a question about the stain that is left on the metal after the rust is removed. I was thinking it should be treated before the primer is sprayed. So I give Sherwin williams help line a call today. What was I thinking? The lady told me I was using the wrong thing. That I needed to talk with my paint guy to see what he was going to use for paint before I use any primer. It might take me a few years to save money for body work and paint. Well I am trying to remove as much of the paint/rust before I take the truck to the body shop so I can save a little money. Bottom line from the lady is I need to talk to my paint guy before I do any paint removel. Is that true. And what is the best way to treat that rust stain or do I need to with the self etch primer? I am confused as what to do now.

If the truck is stored inside then you can do a pretty good job of keeping bare metal from flash rusting using a phosphoric acid product like OSPHO. Humidity will still cause some rusting and hand prints will also rust but this can be easily cleaned off with light sanding and more OSPHO. Another way to go if kept inside is to oil the bare metal down. The oil will have to be completely removed with wax and grease remover before painting.

If you keep the truck outside then the problem is harder to overcome. Phosphoric acid products will help remove rust along with normal sanding and wire wheel on angle grinder. Epoxy is really good at sealing metal but it is not UV resistant so sunlight will break it down. I have never used the shaker can epoxy but I doubt it is as good as buying epoxy primer in cans and using a spray gun. I imagine that shaker cans are also more expensive. If you use a phosphoric acid product to remove rust make sure the epoxy primer is compatible. I have used OMNI epoxy primer with acid and it works well. Some epoxy primers are not compatible with acid. One way would be to work in sections like a fender or door. This will allow you to mask off the area and do a better job of painting.

To be honest hardware store Rustoleum applied with a spray gun will do a good job of sealing metal. Again the shaker cans are not as good a product as quart cans. I don't know how far you are taking the restoration but if you a looking for a simple job Rustoleum works. Once it is well dried you could lightly sand it and top coat it for the final paint job. Rustoleum is compatible with phosphoric acid.

epoxy is a good choice, however, GBP 988is not epoxy. Just a self etching primer. Not nearly as good as epoxy. My recommendation is to return it and order some Kirker epoxy. Cheaper than most and works well. Epoxy is waterproof. most other types will allow moisture to penetrate and rust the base metal with long storage. Any type of primer/finish will adhere to epoxies so you don't have to worry about brands etc.

When I repainted my tractor after stripping down to bare metal I used Picklex-20. It's pricey, but allowed the parts to be stored in my garage for several months without any flash rusting seen. I'm sure it would have went longer, but it warmed up enough to paint by then.