The Stovebolt Site Forums The Shop Area Paint and Body Shop Expoxy primer over other primer

I'm working on old junk and and dealing with pitted metal. To get the pits out after mediablasting I skimcoat with bodyfiller and sand to bare metal 2-3 times and then use highbuild primer and glaze the odd spot to get a good finish.
Once complete can I top this with epoxy primer?
Thanks, oj

The cart may be in front of the horse but you can shoot the epoxy on top no problems...
At this point you could mix it with some reducer 1:1:1 and just use it as a sealer coat and spray your top coat.

Agreed. Read the label on the epoxy primer. I don't think all epoxy primers are reduced 1:1:1.

OJ, high build primers are not always direct to metal primers. Check your data sheet to see if it is compatible or if you may be risking delamination. Once you've crossed that hurdle, you should have no issue spraying epoxy over top of a high build, epoxy makes a good sealer. For next time, I'd spray the epoxy on the bare steel..

Thanks Robert, I see what you mean. I'll check.

Perfect world? Epoxy first - nothing is better. Then fillers and sealers as needed.

Good luck

After blasting, go with the epoxy first, then skim coat with filler, then high build prime, that's the beauty of the epoxy.

One rule of thumb is anytime you apply ANY product over another product, the product you just applied is dependent on the product under it for adhesion. If the first product applied fails everything on top of it fails. When I was a body man epoxy primer wasn't invented yet so all we had was primer/surfacer (similar to what is called "high build" primer today). It was adequate for the time but epoxy primer is much better at both adhesion and metal protection. I've read you could coat a panel with epoxy primer and leave it at the bottom of a swimming pool for months without it rusting. I've not tried that but I would apply the epoxy primer first then the filling primer.

What brand of epoxy primer are you using ?

I use SPI (Southern Polyurethanes)in black. Black makes it easy to see the low (shiny) spots in the metal when doing your body work. They have gray, white, and burnt-red as well. For an epoxy it sands fairly easy. I've learned that you can reduce it to make the sheen more flat for frames, radiators, fender wells, etc.

They recommend a 30 minute induction time. Since I've learned the hard way to follow paint manufacturer's instructions I do this. Quite honestly it is a PITA if you short yourself an ounce or two when spraying. But it is a very durable product.

While you may find the 30 min induction a little PITA Scott... I find the fact I can leave it inducing for 5 days very liberating

I often mix it a day or more ahead of time. Then stir and pour.
But for sure it sands nice when its dry.

Good point - you can indeed leave it sit.

What brand are you working with and can it be applied with low pressure gun? What size nozzle?
Thanks oj

Same as 5150Scott...
SPI site (not the forum)
While I did say you 'could' cover up what you have with an epoxy primer I still agree with everyone else about best practice is epoxy first.

HVLP work fine SPI recommends 1.4 nozzle.

Oj you can even brush the stuff if you need to. Watch for air bubbles.

Whenever possible I spray it with the purple HF gun with a 1.5 tip. You can turn it way down for doing smaller parts. Piece of junk gun that I cannot seem to ruin to justify something newer.

Good luck.