to prime or not to prime

[F-100Ranger]

As i get ready to haul my frame to be blasted I'm wondering - if I use the Eastwood frame paints, should I have the blaster also prime the frame. I guess what I'm asking is ( and I'm going to ask Eastwood ) will the blaster's primer interfere with the frame paints out there or is it just good sense to have the frame primed to have an extra barrier from rust?

[hardtailjohn]

Coming to you as a former manufacturer of polyurethane paint and epoxy primer, let me give this advice... contact the company that you're going to buy the paint from (Eastwood, in this case) and follow their recommendations, no matter what everyone says. I did the tech-line for our paint for over a year and I'd say that 70% of the problems were when people followed advice from local "experts", that had no real manufacturing or formulating experience. Every paint and primer is just a bit different, and some can mix, some can't... but the manufacturer will know what's what.
John H.

[F-100Ranger]

John H.,

I spoke with a service rep at Eastwood. He said if I was blasting then I should just paint their frame paint directly to the bare metal as it's an eposy-based paint. He suggested using acetone first to wipe it down.

What do you think?

[oldschoolrods]

Dennis you might want to have the blaster oil the frame down if possible to help it from rusting til you can get it back to paint it, just be sure to clean it good. and work in a well ventilated area with the acetone

[hardtailjohn]

I wouldn't oil it for anyone! I don't care how careful you are, you can't get it all out of a freshly sandblasted piece... I made that mistake before. Follow Eastwood's advice and you'll be fine. You need to keep it dry and warm when you move it, if possible, or at least throw it in the shop and warm it way up when it gets home, and dry all the moisture off it.. there might be just a bit of flash rust, but that will wipe right off if you take care of it right away.
John H.

[oldschoolrods]

Really? What are the disadvantages to oiling...seems to me a good idea but I haven't done it before?

[DuckRyder]

I wouldn't oil it for anyone! I don't care how careful you are, you can't get it all out of a freshly sandblasted piece... ....You need to keep it dry and warm when you move it, if possible, or at least throw it in the shop and warm it way up when it gets home, and dry all the moisture off it.. there might be just a bit of flash rust, but that will wipe right off if you take care of it right away.
John H.

I agree: Also I'm sure Eastwood has some thing like POR15's metal ready to zap the flash rust.

Now, take it from a guy who's 2/3's done with painting a frame, I'd have is professionally sprayed or powder coated. Particularly if I had already sandblasted it.

[FORDification]

Paint will not stick to oily surfaces, obviously. Do you have any idea the amount of work that would be involved with trying to clean every single speck of oil off something the size of a truck frame?? It would be nearly impossible. Anything left behind will prevent the paint from adhering properly. The whole purpose of sandblasting is to remove all impurities from the metal surface...why would you purposely want to put them back on?

I'd suggest planning it out beforehand....that is, have somebody ready and waiting to prime/paint/powdercoat your frame as soon as it gets blasted. You definitely need to do it quickly. However, if you're planning on coating it with POR-15 or Eastwood's Rust Encapsulator you don't need to rush, since that stuff was MADE to go over rust. In fact, POR-15 specifically says in their instructions not to worry if you get a little flash rust on a freshly cleaned surface, since it was actually designed to chemically fuse to the rust. A tiny bit of flash rust won't hurt a thing.

[hardtailjohn]

Not only wont the paint want to stick now, if you oil it, the oil will find it's way out for the rest of your life and work through the paint/primer, lifting them from the metal and making one big mess! You have to remember, you're making millions of tiny craters in the metal when you sandblast, and oil will hide in them forever. Like the ad says, You try soaking them out, you try scrubbing them out... but they just keep coming through.
Remember that primer is porous, and that's one of the most important ways it helps paint stick. It's sorta like a sponge, so it will let the oil work up through and attack the underside of the paint. University of Nebraska (if my mind serves me..) developed a paint "stripper" that was mostly corn oil, and it worked on that principle. I never tried it, but read a bunch of tech stuff on it, as we were considering it.
Most powdercoat shops do sandblasting right there and will throw the frame in an oven and "bake" it for a while before they sandblast it, to get the oil that's on it to flow out, so it can be blasted off... it makes a huge difference!
John H.

[oldschoolrods]

thanks for clarifying for me, did not think of that