The Stovebolt Site Forums The Shop Area Paint and Body Shop EpoxyPrimer?

I'm in the process of striping my cab down,a little hear and a little there when I get time.My local paint store suggested epoxy primer on the spots until I get the entire thing done,but this seems like a lot of trouble.They said the epoxy must be removed before any body filler can be applied.I'm a novice so I'm looking for the best/easiest way.Any advise would be appreciated Thanks.

I was doing the same and just went ahead and used por-15

There are well-known and high-quality epoxy primers that allow body filler to be applied over it (as long as appropriate procedures are followed). This is very commonly done during restorations.

What brand of epoxy primer are you using?

Once POR has cured, it can be painted-over, but cured POR has to be tediously and carefully prepped for over-coating. POR recommends covering it with a primer that is applied before the POR layer cures (I have successfully used an PPG DP epoxy).

I'll probably be using PPG products.I guess I will get the entire cab stripped before I use POR 15 and epoxy primer.Just worried about the bare metal waiting to be sealed.

I'm no expert, but I used Omni epoxy primer over bare metal. It sticks good, seals the metal to prevent rust, and in some places I used some filler over the epoxy with no troubles. It's a medium cost primer, there are probably better more expensive epoxy primers out there. It's not really a primer you will be able to sand much, it gets pretty hard. You can read the spec's for it online, or just google it.

If you aren't going to paint over it right away you will probably need to scratch coat it before you cover it with primer/paint later.

I also used a high build primer in areas that had some pitting, sanded down to fill the pits.

May I ask why you are using POR 15 as the first coat? If you have some rusty areas there are other products that are much easier to use under the same circumstances. I used EASTWOOD RUST ENCAPSULATOR. It's thinned with lacquer thinner, sprays easily and can be used under any primer.

But that's just my opinion based on my personal experience.

If you are just looking to cover the bare metal and intend to go back in and grind it off and do body/metal work, then I would not spend the money on epoxy. If you have your project inside, then a regular/cheaper primer should work to cover for a month or two. As you know,the non epoxy primer will allow moisrure to penetrate to the metal and then you are back to rust city, so keep it in the shop.

If you are keeping the cab dry in a garage, the other option is to use phosphoric acid on the bare metal. The phosphoric acid (brands such as Ospho) are misted on with a pump up sprayer, scuffed with a scuff pad, then wiped with a paper towel. The surface of the metal won't rust after this application unless it gets wet. When you are ready to primer or bondo, you scuff the surface with scuff pad or sand paper before cleaning and priming or bondoing.

One caveat with using phosphoric acid is not to use an etch primer or epoxy that contains acid when you coat it, otherwise you can have delamination issues.

I live in New Orleans with high humidity and this still works well for me for parts that are stripped and in the garage waiting final body work and paint.

I hope this is helpful.
Regards,
Steve
New Orleans