Self-etching primer vs. epoxy primer

CMD82 · 05-20-09, 07:16 PM

Mud experts... In the process of a semi - resto on my 60. I have all the doors, hatch, and hood removed for sanding and prep for primer and paint; same situation with the body. My question is that I do not have access to a paint gun or experience to operate one, so epoxy primer is not an option. Is the application of self-etching primer over bare metal and uniform paint, adequate before spraying high build primer? Obviously I DO NOT want any rust to return under the new paint that will ultimately be applied either by myself somehow or a paint shop.
Thanks,
Chris

Wile E Coyote · 05-21-09, 02:07 AM

If I understand your post correctly... Try to avoid SE primer over anything other than bare metal. I say try to avoid, in that the less SE primer over paint, the better, as I understand it. The spray can SE primers are lacquer paint mixed with phosphoric acid. (The etching part) The acid can cause the old paint to lift at the edges.

copasspupil · 05-21-09, 06:39 AM

Everytime I asked about epoxy vs. etching at the paint shop...DP90 was the suggestion or epoxy primer in whatever manufacturer you can get.

Buy a gun and try it. It is not as hard as you might think. HF has some actually nice HVLP guns or buy a Iwata 400 lph on ebay. I kow it souns scary and you might even doubt your own skill level but primer and paint are more forgiving then you might think. Wetsanding is always in your back pocket.

You can shoot the primers outside since it really doesn't matter on the bug level anyway since you are sanding so much off. You can make your own booth in the garage and be proud of yur work after. Again, give it a try and enjoy it. The only suggestion is to keep your wrist from moving. Move your arm and body only not your wrist. If you are doing one color not a ig deal but metallics is a must. A god site to ask aint and body questions is Welcome To Autobodystore.com

PM me if you have any other questions or if I didn't make myself clear enough.

CMD82 · 05-21-09, 09:17 AM

Thanks Danno,
I considered trying to create my own paint booth in the garage. Is DP90 an epoxy primer? Without researching, I assume epoxy primer can be applied over bare metal and original paint? Thanks for the tips.

Chris

copasspupil · 05-21-09, 09:54 AM

Exactly. Great primer from PPG. Only issue is that you have to use either a high build or BC within a week of applying the epoxy due to it completely sealing then. If you shoot epoxy and want longer than 1 week, all you have to do if scuff it with a scotch pad over the entire surface and shoot dp90/epoxy again to reactivate the primer.

As far as shooting paint. The compressor must be a minimum of 25 ft. from the water/air separator in order to not have water in the line. PPG also makes a lower priced epoxy primer similar to dp90. The dp90 is what I shot on my mustang. I'll probably use the lesser priced one on mine due to not wanting to make a trailer queen with my 40.

OMNI is PPG lesser priced paint/primers.

toomanytoyzz · 05-21-09, 10:00 AM

DP90 is epoxy. You can apply it over metal along with paint, but I would recommend a 2k high build primer to use over properly sanded/prepped paint. I've used PPG's DP series for years (the older stuff that wasn't lead free was better in my opinion), but was recently turned onto Montana Big Sky's line of epoxy and high build primers. The stuff is great and you get way more for your buck. DP's line only gives you a gallon + 1 quart with their kit. I'd stick with epoxy primers. I'm sure others will argue this, but self etching primers are a thing of the past. Epoxy is more versatile for autobody applications.

CMD82 · 05-21-09, 11:23 AM

Great! Just a quick question... "The compressor must be a minimum of 25 ft. from the water/air separator in order to not have water in the line." To clarify, the hose from the compressor needs to be at least 25ft in length with the air/oil seperator being on the unit? I just have a Craftsman compressor 5hp, 6gal, 90psi, 125psi max, will this be adequate? I assume the compressor as a oil/water seperator on it, or do I need to install one?

copasspupil · 05-21-09, 03:25 PM

You need a water sep. not on the compressor. From the compressor...you would hard line for 25 ft., then install the sep. gauge then outlet. A 6 or 60 gallon compressor? 60 is what I have and it ran fine. 30 or less I'd be leary or better yet, buy a new one.

You can use black pipe or copper tubing. I chose coper since I wanted something easy to install, light and went up in < 30 minutes. The ends and bends were from HD called shark something. They are good u to 200 psi which is way more than I plan on using.

pillguy · 12-10-09, 02:16 PM

OK, not trying to hijack the thread, but my situation is preping a rear bumper & swing out carrier (bare metal) and paint with rattle can SEM chipguard black. What is easiest, ie fewest steps in terms of a primer as I am more leaning towards option 2
2 options)
1)self etching primer (rattle can) or
2)I was told Sherwinn williams has automotive self etching primer then seal it with what ever sealer they sell. roughly $85 for 1 qt of each and reducer included.

My setup is a typical homeowner garage, with compressor.

azcactus · 01-20-10, 07:07 AM

I am painting my whole rig with cans as I have muscular Dystrophy and can only do a little at a time anyway. Not knowing anything about painting a rig we have a place in Mesa, AZ. called SpaceAge or House of Color. I use their opinions. I have some places that I had to DA sand down to bare metal and I used 120 grit. I took them outside to look and was told I would have to use some etching over the bare metal. The product was SEM #39683 self etching primer gray 16oz can did more than one front fender. These cans are not cheap $17.69 One coat .Then I picked SEM High Build Primer Surfacer in Beige # 42023 Beige, looks tan. $18.06 16 oz. Two coats. I picked the beigehigh build primer surfacer becaus it is the closest to the paint I am using. Aervoe Military Digital Pattern Camo Paint. This is a long lasting non reflective finish. 12oz $ 5.42. I have a 50 gal. 5hp compressor and I really need it to use all the air tools I have that makes my life easier and a little less painfull. I know this is going to be expensive with these cans but for me I have to do it. DOES ANYONE KNOW WHERE THERE IS AN ONLINE SOURCE FOR THE SPECIFIC PRODUCTS I AM USEING? By the way, It looks great just with the two coats of 42023 Beige SEM High Build Primer Surfacer. I run it though the desert in AZ allot and dont care about scratches. We call it Arizona Pin Stiping. But that Aervoe 1079 Light Tan(479) is an enamel thai is exceptioally resistant to harsh environmental conditions. Must be true, it says it on the back of the can! LOL

Hugh Heifer · 02-09-10, 03:35 PM

You can get the SEM stuff on Amazon. I use the spray cans of the self etching on small stuff when i take it out of my blast cabinet. I clean it with lacquer thinner and hit it with two lite coats.

twoyotas · 03-04-10, 07:57 PM

Quote:

Originally Posted by azcactus

I am painting my whole rig with cans as I have muscular Dystrophy and can only do a little at a time anyway. Not knowing anything about painting a rig we have a place in Mesa, AZ. called SpaceAge or House of Color. I use their opinions. I have some places that I had to DA sand down to bare metal and I used 120 grit. I took them outside to look and was told I would have to use some etching over the bare metal. The product was SEM #39683 self etching primer gray 16oz can did more than one front fender. These cans are not cheap $17.69 One coat .Then I picked SEM High Build Primer Surfacer in Beige # 42023 Beige, looks tan. $18.06 16 oz. Two coats. I picked the beigehigh build primer surfacer becaus it is the closest to the paint I am using. Aervoe Military Digital Pattern Camo Paint. This is a long lasting non reflective finish. 12oz $ 5.42. I have a 50 gal. 5hp compressor and I really need it to use all the air tools I have that makes my life easier and a little less painfull. I know this is going to be expensive with these cans but for me I have to do it. DOES ANYONE KNOW WHERE THERE IS AN ONLINE SOURCE FOR THE SPECIFIC PRODUCTS I AM USEING? By the way, It looks great just with the two coats of 42023 Beige SEM High Build Primer Surfacer. I run it though the desert in AZ allot and dont care about scratches. We call it Arizona Pin Stiping. But that Aervoe 1079 Light Tan(479) is an enamel thai is exceptioally resistant to harsh environmental conditions. Must be true, it says it on the back of the can! LOL

tcpglobal.com has the primer you are using for about $4 a can less. they dont carry the aervoe product, but they do have a huge selection of many types of paint, from rattle cans to airbrush, to multi stage (several types) , and all the paint supplies you could need.

KY Longhunter · 03-31-10, 04:14 PM

Can I apply Self Etching primer over light flash rust?

Or better to use the Epoxy Primer over light flash rust?

toomanytoyzz · 04-01-10, 01:16 PM

Quote:

Originally Posted by KY Longhunter

Can I apply Self Etching primer over light flash rust?

Or better to use the Epoxy Primer over light flash rust?

If it's flash rust just sand it off with 180 grit sandpaper. You really don't want to ever paint over any type of rust even though POR15 recommends.