Self-etching primer

sballard · 03-04-2008, 04:42 AM

Pardon my ignorance here but what exactly is the proper use of self-etching primer? I assume that it is designed to etch clean metal surfaces to ensure good adhesion of the primer. Can it be used over scuffed painted surfaces and filler as well?

jm529 · 03-04-2008, 05:54 AM

etching primer was designed for bare metal only and can cause problems over painted surfaces. recently more and more shops are going to epoxy primers as bare metal primers and sealers now because of the occasional problems with the acids in etching primers.

herman maire · 03-23-2008, 10:03 AM

Is what jm529 says true?

A few questions I have, I have a bare metal quarter panel that I just installed that needs some filler work where I welded....

1- Do I spray the weld area with dupont self etch primer then work the filler then epoxy primer then sealer?

2- Is it better to just spray a epoxy primer over the bear metal then work the filler OR filler first ?

I'm all mixed up. Help please.

Thank you

repp · 03-23-2008, 11:28 AM

Yes It Is .

jm529 · 03-23-2008, 06:34 PM

herman, if the seam is visable and might have pin holes, i would mix up some epoxy and just brush some in the welded seam to protect the weld from moisture coming from behind it. i would also use a waterproof filler like one of the fiberglas reinforced fillers as the first coat to further protect it. if the welds were done right, there wouldn't be a noticable seam and then you can just grind the welds and use the fiberglas filler over the bare metal. remember, all fillers seem to stick better to just clean bare metal and were designed to be used over bare metal. hope this helps you some.

herman maire · 03-26-2008, 09:40 AM

Quote:

Originally Posted by jm529

herman, if the seam is visable and might have pin holes, i would mix up some epoxy and just brush some in the welded seam to protect the weld from moisture coming from behind it. i would also use a waterproof filler like one of the fiberglas reinforced fillers as the first coat to further protect it. if the welds were done right, there wouldn't be a noticable seam and then you can just grind the welds and use the fiberglas filler over the bare metal. remember, all fillers seem to stick better to just clean bare metal and were designed to be used over bare metal. hope this helps you some.

Thank you for the reply.

My weld should have no pin holes ( I checked it with a light on top while I looked underneath, I had a few but welded them shut) The problem is that it got a bit warped because I was loosing patience

and started welding for longer stretches .

Is it Ok to apply the filler over the epoxy primer? Would it stick? I dont think there would be room for the fiberglass filler.

Thanks again

jm529 · 03-26-2008, 02:42 PM

the filler will stick to the primer but will stick to bare metal better (that was ground down to provide better adhesion) .

Chas White · 03-27-2008, 02:51 PM

I always thought the deal was to cover the metal with epoxy primer to protect it from moisture, then do the filler, so if the filler does absorb moisture, the moisture will not get to the metal.

charlie