New fender prep

FlaJunkie · 10-06-2010, 04:51:59 PM

My new EDP coated fenders, hood, etc. need painting.

Does anyone else think first cleaning them thoroughly with soap & water is a sound idea?

What grade/type scotch pad is need to rough up the surface for painting?

Can base go over the roughed up EDP parts without a primer?

Thanks to the Camaro brain trust...

BTTB71SS · 10-06-2010, 04:55:46 PM

Personally i always stripped the edp coating off and then primered the parts...

Then you can put you color on after that.

Never did trust edp since all after markets parts come from asia

olstyle · 10-06-2010, 05:20:05 PM

I agree. I sanded all the edp coating off all my new parts with 80 grit on my da then put on epoxy primer.

Rick WI · 10-06-2010, 05:21:21 PM

Strip to bare. That coating can be an issue with top coats as solvents can soak into it. If it was an original OEM panel from a real factory not an issue typically. Import oversea Tiawan stuff a whole other story.

Strip it to bare, epoxy and 2k primer surface. The block straight with a 400 as final prior to paint.

FlaJunkie · 10-10-2010, 10:41:57 PM

How can you tell if it is a lousy EDP panel? The hood would be very hard to strip the EDP coating off of.

Paint Fumes · 10-11-2010, 12:11:55 AM

I sand the outside of new aftermarket parts to bare metal with 80 on a DA. You can go over the 80 marks with 180 if you don't feel comfortable with them but they will fill with primer, no problem. 80 scratches on bare metal aren't very deep. Sand the insides of the panels with 320, red scratch pad where you can't get with sandpaper. Clean with wax and grease remover, epoxy prime, then a few coats of urethane primer, block sand with 400 and you're ready to go.

5spd540 · 10-11-2010, 03:46:47 AM

I sand all mine with 180

earlysecond · 10-11-2010, 06:57:17 AM

Sorry to agree but I do.

I am in possession of quarter skins. I believe that they were in dry storage for a year or so after purchase so they were well cared for.

The surface of the "EDP" which is nothing like the factory EDP on these panels has millions of tiny bubbles.

The most concerning thing is that if you look at the outside of these panels carefully in the right light, you can see that somebody wrote something on the bare metal with a paint marker, or other marking device and then the primer was applied right over it. The number are legible as the primer is raised.

Get out your DA. Strip with 80 until nearly all of the black is gone. Switch to 120 or 180 and epoxy. the underside and inside of the hood is the only place I would take my chances and I would still scuff with scotchbrite, the best I could, clean the best I could and hope for the best. The only other option is to media blast and that may be overkill. A good epoxy primer should then be the first step.

Good Luck

ChevyReb · 10-11-2010, 09:39:38 AM

You can also use the 3M sponge disk things on a die grinder or electric drill. Got mine from wal-mart for around $6 each, you will need a couple of them. Worked great for me on my cowl hood especially in the curved corners and vallys and will not gouge into the metal Then get a flexible sanding block or piece of heater hose wrapped with sand paper and go over it with 120 0r 150 grit and reclean it with wax and grease remover and epoxy prime.

wookie · 10-11-2010, 02:11:56 PM

180 them and epoxy away!

FlaJunkie · 10-11-2010, 02:27:43 PM

From another site:

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The EDP coating is a slightly greasy coating to prevent rust.

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True EDP coating shouldn't be greasy. I believe this is refering to the bare metal panels that are coated with light oil to prevent rust until installed.

Most all the import sheetmetal I've seen has the black EDP coating on them and it should be left on them. This is also known as electroplating and it is good stuff.

You can take a rag with laquer thinner on it and wipe the black coating. If it doesn't come off then it is EDP coating. If it does come off on the rag, then it is not EDP and will need to be sanded to bare metal.

If it is EDP (most likely is) all you need to do is scuff it with a scotchbrite pad or similar and shoot the epoxy on it. Then you can proceed with the body work.

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yes i agree, no need to remove the edp coating, just scuff, clean and shoot!

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PPG recommends only using 401 catalyz over EDP panels. I guess there have been issues with the more agressive 402.

As always, check the epoxy maker's product sheet to be sure.

Otherwise, I see no reason to take it off. As a matter of fact I normally don't even bother with epoxy on EDP panels. A quick scotchbrite rub and then high build 2k.

wookie · 10-11-2010, 06:08:51 PM

I just did a hood over the EDP as a test...We'll see how it holds up..

Rich Schmidt · 10-11-2010, 06:44:42 PM

I wipe everything down with prepsol (wax and grease remover) before I take sandpaper to it. If there is any wax or silicone on that panel,it can work it's way into the sanding scratches on the bare metal,or existing paint of whatever it is you are working on. I always wipe down before and after sanding,before priming ect.