The bodyman doing the filler, priming, painting etc gave me a list of material to pick up. Asked for etching primer, PPG outlet gave me DP40LF epoxy primer along with DP401LF epoxy primer catalyst. Reason I am asking on this post I can't get hold of my bodyman right now and just curious about this as it does not state anywhere on the cans that it is an etching primer, I realize they probably come out with new products often and just thought someone here my have an answer for me. This is to apply to the bare metal on the welded joints of the rear quarters.
For a primer they gave me Prima K36, acrylic urethane primer surfacer, along with K201 primer surfacer catalyst

Appreciate the help

Jerry

Spray the DP right over the bare metal, Just wipe down the area you are going to spray with wax and greese remover , I thing it is dx330 ppg. The epoxy is a self etch primer. Do your bodywork right over the DP. You need to find out if the catalyst is the fast or not. What I mean is one of the catalyst , you have to let it sit for half an hour after you mix it.

The Dp or DPLF expoy IS NOT a self etch primer. PPG does not make a self etch expoy to my knowledge and its especially not the DP expoy. Your 401 must be allowed a full 30 minutes induction time to achieve it full performance. Meaing after you mix it it has to sit in the cup for 30 min before spraying. Plus the 401 makes the expoy alittle softer, so if you have to sand it it sands ever harder cause all it will do is gum up. Get the 402. The k36 primer is a great one. I use k38 on own stuff it just has a higher film build then 36. the 201 is the right hardner for k36.

My not a fan of expoy on bare metal and I think most body guys on this site will agree with me. Self etch contains an acid product that bites into the metal, were the expoy just lays on top. The etch in my book has far superior rust and adhsive properties.

Plus you got to use what the body mans wants dont try and change him. I know all the PPG retail stores in my area, the guy behind the counter knows nothing about paint and painting. All he knows is that expoy costs more then etch so thats more money in their pocket...commission check!!

Thanks, I am not sure why the guy there gave me it when I specifically asked for a self etch

Thanks Again

The reason he gave it to you was answered by Eric, the counter man doesn't know the difference. They have been so brain washed by the PPG marketing machine (brilliant marketing I might add) that he to thinks it is an "etch". graemlins/waving.gif

I used DX330 on bare metal before primering and it cleaned very well just evaporates kind of quickly so be quick with it. About 20 bucks for a half liter of it.

One of the self etching primers PPG sells is #1791 and it's catalyst....also ask for product sheet for it's application..they should have one if it's a PPG store.MAKE SURE you wear an air supply mask with ANY 2 parts paints or primers. This stuff is nothing to mess around with.Also ppg does not recommend their etching primer over bondo..only bare metal that is smooth and clean. This will be explained in product sheet. They also have another etching prime...but I don't remember it's # off hand. Sherwin Williams also used to make a excellent etching primer...may want to contact them also..I think it's # was 560 or 561...been a while. Hope this helps. I have used both

If you look at the bottom of the P-sheets or tech sheets you will see a NOTE that states. DX1791 may be used for spot repairs involving existing cured OEM and refinish systems. Slight overlap of dx1791 onto painted surfaces and body filler is acceptable. Been appling etch over filler for years now and yet to see a problem. The problem comes from people appling bondo OVER the etch, which is a BIG NO NO! The chemicals in the creaam hardner can and will react with the acids in the etch causing the bondo to lift...Eric graemlins/waving.gif

Eric, have I got this right then. Bare metal, then etch primer, then the filler?

Jerry

Jerry, the first thing I would do is get all your metal work done, ready for bondo. Clean the car to bare metal, and then apply your filler. Once all the filler work is done then apply the etch.

So it goes bare metal-bondo-etch.

What ever you do DONT apply the etch first then apply the filler OVER it. The chemicals in the bondo as it is changing its chemical state will react with the acids in the etch. This reaction will loosen the bondo from the etch causing it to lift.

SO ALWAYS GO FILLER THEN ETCH

On a side note the other etch from PPG is under the number of DPX171 which is a NON chrome etch. I dont believe this etch is a as good of a etch. I would stick with the DX1791...Eric