Self Etching primer... Good or Bad?

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bluetrane

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Hey guys first time poster. First of all, I'm restoring a 70 dart. I had an old friend doing the body work and paint. He ran off after cutting up my car with alot of my money. So now i'm doing the work on it and i havn't got the slightest clue what i'm doing (i've never done body work). Before he ran off he had me sandblasting body panels and spraying self etching primer. i've got Valspar 1k self etch primer. I've been looking around on the net and i'm not reading too many good things about self ecth primer. Is this good stuff to start with or is it a big mistake. any input would be greatly appreciated. thank you for your time. great site
john
 
Welcome!

Sorry to hear of your misfortune. Sounds like you have a friend like I have. He got me one time and by golly that was the last time.

Some one should be along to help you with your qusestions.
 
Its ok to use it works best if you go down to bare metal.
 
I've been using self etching primer for YEARS and never had a problem.
Don't let the "sky is falling" guys make you nervous. Get the car to bare metal, clean it, and shoot the primer on.
Good Luck.

George
 
Hey guys thanks for the peace of mind. I'm blasting everything but the exterior and spraying it with self etching primer. I'm using paint stripper on the exterior and spraying with the same stuff. I'm sure i'll have many more questions before i'm done with this thing.
 
When you get it to bare metal get all your sheetmetal work done before the bodywork. I usually apply a light coat of etching primer then a good epoxy. I have started using DP90LF from PPG since it is an epoxy with etching properties. Two birds with one stone theory. I do all the final bodywork over the epoxy primer.

Good luck and post pics!!
 
I always use etching primer when coating bare metal(chrome to aluminum) Its mildly acidic so it etches itself to the metal, hence, ETCHing primer. I tend to use CUUDA's method, a coat of etch-prime to bite into the bare metal and go from there. Without it, your flake factor could increase. Good luck!
 
It seems the standard practice these days is epoxy prime on bare metal but there have been countless paint jobs for years using etching primer with 2k on top of that. If applied per manufacturer specs it will (and has for years) work fine. Whatever product you use, if you follow the manufacturers recommendations and don't shortcut or dream up your own application processes etching primer works fine.
 
The way I've been taught is:
Bare Metal -> Epoxy Primer -> Body Filler ->Epoxy over any filler or bare metal -> Urethane 2k primer -> Sand... -> Urethane 2k primer -> Guide coat -> Sand...basically keep priming and guide coating...and sanding until you have a laser straight panel -> Sealer -> Base Coat -> Clear coat


I've found epoxy primer works well, and is tough as nails.
 
You gotta be careful with using some etch primers with epoxy. They don t all get along. Hence ppg dp epoxies and their green self etch. 171 i believe. Take your time and ask as many questions as you need. Most folks on this site are super helpful and knowledgeable. Good luck
 
Sorry to hear about the flake, that's why I do my own work.


George R said:
I've been using self etching primer for YEARS and never had a problem.
Don't let the "sky is falling" guys make you nervous. Get the car to bare metal, clean it, and shoot the primer on.
Good Luck.

George
Click to expand...



Pretty much the jest of it. Everything else is an option.




Etching can be done mechanically: sanding with 220, or a paint stripping wheel on a grinder.

Or chemically: self etching primer, epoxy primer, etc. same thing.



Your just getting the surface ready for the paint to stick to. Either way is a safety net and borderline overkill because part of the primers job is to increase adhesion anyway, the other part of primer is to even out small imperfections in your metal, think of it like filler, only for less than 1/16" applications.

Don't fall for the denatured hoopla either, that 2$ bottle of 70% percent isopropyl alcohol to clean and hit with a tack cloth right after works great just before primer, and in between coats.

Have fun, and enjoy yourself.. It sounds like its been a stressful enough job already.




Something I'd like to add if your doing any fabrication/metal working:

The Rustoleum BBQ flat black high heat paint works great as a option for weld-thru primer so you don't have to worry about rust between your plug welds.. Seems a little more durable than the regular zinc based that seems to flake off.
 
Not all self itching primers work the same! You can test it if it will react to paint thinner by wiping it down with a cloth, if you notice the primer rubbing of it no good! Remember that automotive paint uses thinner. Good luck on your Project!
 
I have been using the PPG DP Epoxy's for more than 25 years, with never a problem. It has stood the test of time over and over again on jobs that ran through my shop. Some epoxy products I wouldn't trust, personally. Just make sure if you are using a chemical stripper on panels to make sure it is thoroughly cleaned off before any top coat is put on or it will come up through on you later.
 
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