What should be used to prime bare steel?

The title says it all. I'm not sure if I should use epoxy primer or self-etching. The more I ask, the more opinions I get- though I trust the ones I get here. Anyone?

Thanks!

 

Most local guys here use an epoxy primer and then a topcoat. Depends on your desired finish. I've seen a frame done in a restoration that was blasted to bare steel, epoxy primed with 2-3 coats and lft as is. Held up fine after 3 years. Check with your paint store/sales rep. I highly recommend using one system/brand all the way thru. The first thing they'll blame if you have an "issue" is the other brand product. HTH

 

Mike if you're talking about the frame just do it with the Eastwood Rust encapsulator or POR 15 no primer needed and not recommended. This has held up well since I used it in march. As far as the body goes you're on your own, I haven't made it that far yet.

 

I've had good luck with epoxy primers. It cures instead of dries and gets rock hard. If it's something like a frame you may be able to topcoat without sanding and have it chemically bond instead of physically. Ask your local store.

 

From Carey, the pro painter, on the FSJ board:

"You can use either etch or epoxy. I wouldnt say either is better. youll just need to pick one and go with it..They both have good and bad.

Epoxy is a two part product made up mostly of epoxy resins, so its pretty slow drying. It needs at min 60 degrees to cure..its generally mixed in a 2 to 1 ratio with the hardner being the lessor amount..After applying youll need to let it sit for at least an hour till you can coat it with primer..It has a 3 day window before it needs to be sanded. So you can epoxy one day and prime the next without worrying about needing to sand it to get the primer to stick.. It makes more of a glue bond or resin bond more than a chemical bond..It works VERY well as an etching product also..It also has some filling characteristics so you can minus a coat of primer you will be needing..Epoxy has the capability to make a hard barrier to any previous paint. It protects the new paint from counteracting/soak thru, with the old paint. After 2-3 hours you cannot rewet it. The primer reacts with the resins, and thats what make the primer stick to it. Epoxy works best with two medium coats but can be made to work with one heavy coat. I prefer two meduim coats..

The MFR's came out with etch to make things quicker in bodyshops..It makes a chemical bond to the metal. It is also a two part product, it is not a hardened product as it uses acids to bond it with the metal...It smells terrible and will really burn your eyes.. It needs to be recoated in less than 1 hour our youll need to sand it to continue. It can be sprayed in one over medium coat but has no fill characteristics, it drys very thin..It also has no barrier capabilities. Its best only used on big bare steel surfaces. The primer rewets it, thats how it bonds itself to the primer..

They both have there pluses and minuses, many people still use epoxy, the etch is somewhat new."

 

I thought about the POR and rust encapsulator products though I think I'm leaning towards epoxy at this point. Turns out epoxy is pretty cheap through my local supplier. I am going to use the Gillespie Coatings original drab green single stage enamel for 2 reasons- it's cheap and it's what was originally used on my A1. Someone somewhere told me that epoxy primer is compatible with most if not any other kind of topcoat. So hopefully I shouldn't have any problems (crossing fingers)....



Thanks for the input!

 

I've used epoxy primer top coated with Gillespe paint. Has worked very well for me. The alkyd enamel just sticks without problem and is pretty tough when used with a good hardner. Plus it's easy fix if I need to.

 

FWIW I used self-etching rattlecans for the rocker guards on my TJ. Of course the rocks get through to the bare metal but some of the gentler taps will get through the Rustoleum Hammered topcoats and not through the primer. They're holding up much better than the bumper I did with Rustoleum primer and Hammered topcoats. Both were bare steel when I started.

Thanks, all, great site!