Wurth Self-Etching Primer

RWebb · RWebb's Garage

Is this a "must use" on bare metal surfaces?

What is a self-etching primer, anyway? Does it have some acid that etches into the metal mixed in with the primer?

I am not going to paint the car body, I just want to do a good job of painting some parts.

moneymanager · 02-21-2009, 01:36 PM

Eastwood has a good primer on primers. In my experience self etching really does help when painting aluminum.

efhughes3 · efhughes3's Garage

I always use that stuff-paint sticks and stays in my experience.

Buckterrier · 02-21-2009, 02:12 PM

Quote:

Originally Posted by RWebb

Is this a "must use" on bare metal surfaces?

What is a self-etching primer, anyway? Does it have some acid that etches into the metal mixed in with the primer?

Yes that's about it in a nut shell. Usually phosphoric acid and some zinc. This adds to the corrosion resistance of the paint system. It etches, (chemically scratches), the surface for adhesion and corrosion protection. A poor man's pre-treatment if you will.

RWebb · RWebb's Garage

OK, is there anything just as good that is likely to be locally available?

shipping charges make buying a single rattle can of this stuff pretty expensive...

Zeke · 02-21-2009, 02:23 PM

I don't know if I'd call it a "poor man's treatment."

Randy, if you use any major brand finishing system from primer to top coat, you should be good. A many time concours winner of 356 fame here in Long Beach uses polyester primer on bare metal and nothing else until it's time to seal and spray. No epoxy and no etching. He does etch and neutralize by hand according to his painter, whom I have spoken to several times.

Oh, and I wouldn't use a rattle can of anything. It's not the same formula (in many cases) as the bulk item. Too thin.

redstormcoach · 02-21-2009, 02:25 PM

Self etching primer is available at NAPA. Just bought some along with Enamel paint to paint my H4 Trim Rings.

Buckterrier · 02-21-2009, 02:31 PM

Quote:

Originally Posted by milt

I don't know if I'd call it a "poor man's treatment."

A poor mans pre-treatment

. When I say pre-treatment I mean using a zinc or at the very least an iron phosphate and a non-chrome sealer. The etching primers kinda-sorta-maybe act as both, phosphate & primer.

RWebb · RWebb's Garage

thx

milt - the Wurth stuff IS in a rattle can

is it not very good?

again, surface finish is not an issue...

moneymanager · 02-21-2009, 03:22 PM

I've never used a Wurth product which wasn't clearly superior. Ever tried their flat black? In a league by itself, even out of a can!

Zeke · 02-21-2009, 03:34 PM

What are you using it for? I assumed body work. I use rattle cans on small parts. Anyway, if in a can, that will be reasonable. Buy all kinds of primers, thinners, catalysts and such for one project and empty the wallet. They all seem to come with their own set of dedicated ingredients.

At least a rattle can is all-in-one. But, see, that's part of my point.

lindemans · 02-21-2009, 03:48 PM

Keep in mind that epoxy primer / surfacer / bondo does not stick to etching washprimers; make sure you use a suitable surfacer that does.

Zeke · 02-21-2009, 03:49 PM

What's a washprimer?

moneymanager · 02-21-2009, 03:50 PM

Thanks for reminding us of that. You are of course exactly correct.

porsche930dude · porsche930dude's Garage

duplicolor makes self etching primer i get it all the time at auto-zone and advance auto. I think it works good because when i get a scratch in my paint i can still see the green primer in good shape underneth

Jim75911S · Jim75911S's Garage

I have used both Duplicolor and Eastwood brand self ecthing primers recently. Both work well however the Eastwood product seems to give you more bang for the buck. Most of the parts I use it on are small or midsize (bolts, dust shields, etc.). I have found the best way to get good results with a rattle can is to follow the directions completely.

RWebb · RWebb's Garage

yes, small parts

body is done

frankc · 02-21-2009, 05:54 PM

I'm getting ready to paint my engine bay and have a couple of small areas that will be painted from bare metal - the rest I plan to spray over the existing paint. So should I use the self-etching primer on the bare metal areas only, and not the existing paint?

BoxsterGT · 02-21-2009, 06:13 PM

While we are on the subject of primers, does anyone know who sells a modern primer that matches the olive green color of Porsche's original "old stock" body panels?

I have a NOS front inner panel that has some surface rust. I would like to restore it to its "old stock" condition.

I think primers today can be "tinted".

Perhaps that's a possibility.

Len

joefrantz · 02-21-2009, 06:16 PM

SEM makes a really nice self etching primer in a spray can.
I use it under Wurth satin trim paint for small parts.
It's available in gray or black.
Not sure where in Oregon you're located, but here is a list of sources from their website.

http://semproducts.com/Suppliers2.asp?state=OR&p=1

Joe