When I say self etching I'm referring to the coating that comes on better quality patch panels. Am I correct.
I don't know what primer is on those patch panels, I'm referring to epoxy primer or self etching primer you spray on yourself so you know what it is.
If you're referring to E coat (typically the black coating on replacement panels), I would not trust my future paint job over it. I'd strip it, prep the metal then lay down your high quality primer. I've seen it chip, lift and have seen panels with areas of slight surface rust under the coating. I've heard some e coat is now water based.
Well thanks for all the replies. I just like to get all my ducks in a row before I begin. I was told that the aerosol self etching primer is ok to use but then the question of filler over bare metal or over self etching/ epoxy raises its head with basically two camps, pro and con. Any comments on that issue?
Some epoxy primers can have filler applied over them but absolutely follow the manufacturers instructions just as they say to do it, no shortcuts and you will be OK, I don't know of any self etching primers that you can apply filler over.
Just remember, if you are using self-etching primer, it NEVER goes over ANYTHING but bare metal. My former boss is repainting several customer cars, at tremendous expense, because he did not heed this warning.
In the past I have scuffed and shot paint over e-coat in genuine GM pannels and thats the way the local dealer was doing it also...but I had heard the same thing you just mentioned recently and I stripped all the e-coat off some Chinese bedsides to find some rust under it in a couple spots sooo if Chinese ... Defiantly strip it.. Better safe than sorry
do your mud work over a good epoxy primer....another thing....never apply seam sealer over etch primer...etch has what in it??? Acid..... Acid eats away at things...like seam sealer...etch primer became abused when they put in in aerosol cans....always go with a solid 2K primer
All metal should be used right on the bare metal. The strength of adhesion is only as good as the layer underneath right?
More good advice. What I'm getting is self etching primer has a very limited use, why bother using it at all except for bare metal that will go straight to colour. Thanks everyone.
Bondo 101 -- for new guys and some old guys. Long read, but it might save some headaches, some money, and clear some things up. (It is NOT penicillin!) http://www.jalopyjournal.com/forum/threads/body-tech-bondo-101-magic-dent-erasing-compound.8318/
The Jalopy Journal
