I have tired both methods of primers Epoxy and Etching primer. I did a 57 chevy bare metal shot epoxy primer over it, did my body work. Filler etc...
Before you prime it make sure the metal is flat as possible so you won't go crazy banging high spots down and refilling.
Prime the metal with epoxy primer, do your bodywork, sand filler using 320-360 grit before priming with 2k primer.
Check bodywork, I would block sand it, 2k high build primer the rest of the car, even non metal areas, over filler, over everything. block sand, seal, base and clear.
Although you can paint base directly over your 2k primer. I've had beautiful finishes painting right over 2k primer.
Hope that helps!!
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Originally Posted by Ron M
I am working on a 49 Chev car, and as I strip the paint, I am finding old bondo and some areas where there is surface rust under the bondo and old paint. Some of the paint has also been chipped as well having surface rust. I was planning on using PPG MP 170 Epoxy, but after doing some reading on the net, it sounds like a self etching primer would be the course. The article stated that on older restorations, it is better use a self etching primer for metal with surface rust. The article also said that self etch primer was better for corrosion resistance. HUh.... I thought epoxy was the way to go, ofcourse I have not painted since the old DP primer was the thing to use, or is epoxy still the way to go.
If I go with self etch, here is what I was thinking to do. First I have some large weld seams in this body, and I know there may be a few small pinholes in the weld areas. Had a hell of a time with the 110 mig in some areas. On the weld areas, I am planning on using POR15 and seam sealer on the back of the welds, MP epoxy on the outside, filler on top of MP170. I was then thinking maybe spray the body with self etch primer and then 2K, block and paint. My thinking with the MP under the filler was that it would help seal the weld areas from moisture and I already have about a quart from another project. I was then thinking that th etch on top would be the way to go since I thought I read etch primer and filler do not get along well. Can I go ahead and spray etch primer and do filler over that or what is the best way to go in this case?