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Etching Primer vs. Epoxy

2233 Views 5 Replies 6 Participants Last post by  collins motors co.
I'm starting a new project and need some advice on metal preperation. The car has several layers of old paint and needs to be stripped. I'm sure I'll find some rust along the way. After it's down to bare metal, should I use an expoxy primer or etching primer? What is the difference? I spoke to a few different paint suppliers and I get different suggestions. Thanks.
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I personally like the etching primer because it perportedly eats into the steel surface. Also, the epoxy primers are illegal in Calif, at least for sealeer coats. Maybe they are still legal for bare metal. Not sure. We can still use two part polyester primers which go over the etch primer base and fill and stick as well as the epoxy ones do. Also a BUNCH cheaper!
It kinda depends how you strip the car. If you soda blast it or use a stripping chemical, you should use and etching primer becuase the smooth metal surface was not disrupted. But if you have it blasted with another type of media that gives it a rough surface, then you can use epoxy primer.
Ditto with Drgnwgn. If you use a DA or sand blast the epoxy will have no problem. I personally like epoxy. I tryed on my most recent project after stipping it with 80 grit. It worked very well, and is hard as nails. No chance of it coming off.

I use both myself. Some epoxies adhear better with the etching primer under them. And the paint co.'s recommend doing it that way.
I think both dp. and etch primers have their place.Etch primer sticks better to bare metal than epoxy its thinner and does not have the shrinkage dp does.You can not put bondo or all metal over etch like you can over dp I'll spray a coat of dp over any welds I'm going to put filler over, and I,ll use dp90 as a sealer over etch on a frame or something like that.For a sealer I prefer urethane 2k sealers dp stays wet and shrinks to much.In the early 80's there was nothing better than epoxy for adhesion that was flexable and worked with most top coats now theres more options.
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