Question for the paint experts. I didnt use any etch primmer on my fenders. They have maybe 40% filler covering them and I left some old paint on them also.i got a little spooked and went ahead and shot some PPG K36 on them front and back to avoid flash rust.Will this be ok? i still have some work left to do on them and will be spraying at least two more coats on them. I do have a can of eastwoods etch could I have used it? thanks in advance for all replies...Ed smile.gif

Let me put it this way, Etch primer under your urethane primer is BEST for adhesion and corrosion protection, period.

Many, Many shops and hobbiest do not use etch, it is not going to "fail" like you did something "wrong". But it is better if the etch was under the urethane.

I went to my paint store and asked for an etch primer and he gave me a wash primer.What's the difference?I used it under my 2k primer. :confused: Is this normal?
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Rick

Rick, "Wash" primer is a very thin etch primer. It is just fine and in fact better than the heavier bodied ecth under most condtions.

Ok so if I end up sanding most of the k36 off to complete filler work (this wes my first time and needs some work) should I etch them and then use the k36? I'm worried about the mills.Also what order should the moisture filter be in.Is it gun,filter then reg? Thanks Martinsr for your repplys.... :cool:

Ed, it depends on the type of filter. As far as the etch, it depends on the etch primer. What brand and part number is it. If you are concerned with the film thickness being too much, don't be. The etch is usually about 1.5 mils or less with wash etch being only .5 or so. It is designed to work with the urethane, and a required product with most lifetime warrantees. So it works, that we know.

I wouldnt worry about it, I have shot K200 primer surfacer right over bare metal and repair work with no etch primer. I havent had any problems, but these cars dont see much bad weather driving. Not sure what the difference would be with the etch primer.

The filter is a pisposable orange type.and the etch I have is eastwoods in a rattle can.I was scared to mix brands but am will to get a pint of ppg wash ethc just to make sure it done correctly. thanks Ed. ;)

Ed PPG has several etch primers to choose from. The three that come to mind are dx1791,dpx170 and dpx171. I use the dx1791. The dpx170 contains chrome pigments and also is a WASH primer. Dpx170 may be prohibitied in your area because of the chrome pigments. The dpx171 is a chrome free etch primer. Now whether which primer is the best all round primer, cant really say am no paint rep, but have used dx1791 for many years and yet to be let down