Epoxy primer

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ir3333

ir3333

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I'm reading that epoxy primer is very difficult to sand. Is there a more modern brand that is sandable weeks or months after appllication?
 
Epoxy Primer is a Primer Sealer.

When doing body work there is a product called Primer Surfacer that sands easy and is used for leveling and filling imperfections and sand scratches over the bondo work.

Primer surfacer works good if you are going to get to the car right away and get it painted right away so it is all sealed up.

People use the Epoxy primer because it is tough and is a good base to put down after a car has been stripped. It seals out moisture penetration too as lots of these cars can sit around for years before they get finished, so it's good to have something to seal the bare metal and keep it from drawing moisture and rusting while you work on it.
 
Got it...but at some time later you will have to sand to do body work ..so what is the easiest epoxy to sand?
 
Short answer, no epoxy primer is not hard to sand.

As George Jets said, epoxy primer is used to seal bare metal and keep moisture out.

So, question #1... did you take/are you taking your car down to bare metal? If so, then you absolutely need to shoot epoxy over it. You will do your body work over the epoxy coat.

Question#2... are you planning on laying down a 2K or 4K primer over the epoxy? These are both thick primers that fill in sanding scratches with no problems. So, you can sand epoxy with a rough grit and not worry about seeing scratches later. Most experienced painters also shoot a coat of sealer right before paint, but that's a personal preference.

What color is your paint? Make sure to use primer that works best with your color. There is white, gray, black, green, even red.
 
yes, i am stripping the whole car to bare metal.It's about half done and i've been working at my leisure for about 3 weeks and will prime it when finished. Bodywork and high build sometime down the road.My shop is very dry so the bare metal is fine.
 
Epoxy, then filler. You may do like some of us and put some epoxy primer over that filler. Then a high build urethane primer. Maybe a guide coat? Block. Seal. Topcoat. Thats just my method. Disclaimer: You want to do different.
 
ir3333 said:
yes, i am stripping the whole car to bare metal.It's about half done and i've been working at my leisure for about 3 weeks and will prime it when finished. Bodywork and high build sometime down the road.My shop is very dry so the bare metal is fine.
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You may think your shop is dry enough but, it's probably not. Also anytime you touch it with bare skin it will rust. Once you get it stripped I would go over the entire car with a DA and 180 grit to make sure any starting of flash rust is gone.
 
ir3333 said:
yes, i am stripping the whole car to bare metal.It's about half done and i've been working at my leisure for about 3 weeks and will prime it when finished. Bodywork and high build sometime down the road.My shop is very dry so the bare metal is fine.
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You have to monitor the relative humidity but rust starts immediately in most cases. Bare metal needs to be resanded after 8 hours if it is not protected. That is what the paint manufacturers recommend.
 
Most epoxy primers sand like bubble gum. They roll up on the paper. One example would dplf from Ppg. It doesn't sand nice and anyone who has tried to sand it would agree. There are newer epoxy primers that sand much better these days.

If you don't have a lot of body work to do why not epoxy the car, wait a day and then high build prime the car? I've never understood why anyone wants to keep sanding an entire car over and over again?
 
I spray my epoxy then put a coat of high build on within the window of the epoxy. This way when im ready to paint its just a quick scuff.
Its not that epoxy doesnt sand, it doesnt sand well meaning you cant get a smooth finish on it. Its not made to be a surfacer.
 
So many different methods, tx guys but back to my original question .... has anyone used a modern epoxy primer that is easy to sand?
 
ir3333 said:
So many different methods, tx guys but back to my original question .... has anyone used a modern epoxy primer that is easy to sand?
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House of Kolor had a nice sanding epoxy. It has changed but I'll bet it didnt get harder to sand. Get into the Southern Polyurethane site. Lots of discussion on there and call Barry. He runs the show and will talk to people. I hear lots of good things about his products and service. https://www.southernpolyurethanes.com/
 
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ir3333 said:
So many different methods, tx guys but back to my original question .... has anyone used a modern epoxy primer that is easy to sand?
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What paint system are you going to use? It is generally best practice to stick to a single paint line. Sikkens is what I spray every day of the week. They have a epoxy primer that can be used as a wet on wet sealer or sandable primer surfacer. EPll

Also there are primer surfacers that are DTM... look at rust defender, or the old school NCP 270 from Ppg.... all paint lines have the products you want.
 
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I used Tamco 662 epoxy primer. DA Metal with 80 grit. Sprayed 2 medium coats. This primer sticks to anything, drys relatively slow. It sanded extremely well with 180 grit outside of the 7 day recoat window.
DTA Epoxy (Direct to Anything)
 
While epoxy primers are generally known for their strong adhesion and durability, some formulations can indeed be challenging to sand weeks or months after application. However, there are modern epoxy primers available that offer improved sandability. It's recommended to look for epoxy primers specifically designed for easy sanding and extended sanding window. Brands like PPG, Sherwin-Williams, and 3M offer epoxy primers with enhanced sanding properties.
Do You Have To Sand Epoxy Primer Before Painting? Our Rules
 
Very few epoxies are sandable. The PPG CRE is good stuff. Its thick as tar and has to be reduced to spray but it sure lays out nice.
 
Call Southern Polyurethane. They'll give you some accurate answers.
 
RustyRatRod said:
Call Southern Polyurethane. They'll give you some accurate answers.
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Can't agree more. The owner, Barry will walk you through all your questions, even help setup your gun. I stripped the Dart, SPI epoxied, body filler over epoxy, used SPI 2k high build, reduced SPI epoxy for a sealer, then paint and their clear. Pics in my build thread. First car I ever painted.
 
Maybe I have just been lucky, but I have never had any trouble sanding epoxy. I always go to bare metal when I do a paint job, and I always spray on 2 full, wet coats of Epoxy on the bare metal. Then I lightly block it with 220 and 320 to see where I need to do body work. Sometimes I break the surface with 120 first, but I am careful not to sand off too much. Then I do the filler work right on top of the epoxy followed by Evercoat G2 polyester primer. I have used epoxy primers from PPG, Eastwood, TP Tools, Kirker and TCP Globel. They all sanded fine. I think I like the Eastwood the best.
 
The std procedure is to spray epoxy primer then a 2K high build primer overtop which is sandable. I notice you can also buy DTM (direct to metal) primers too but I'm sticking with the more common procedure.
 
barbee6043 said:
Hard to beat Southern polyurethanes epoxy and other products. Their epoxy is sandable.
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I love SPI paint, but I have to make a confession to keep someone else from screwing up like I did a week ago. It has been several years since I bought a pile of stuff from them. I called and made an order, and it arrived quickly and well packed. I noticed the round gallon cans of epoxy and 2K primer had plastic rings on the tops to prevent the lids from being accidently knocked loose. When it came time to use the epoxy, I got a flat screwdriver out and tried to get the ring off by prying it loose from on top of the lid. It wasn't budging, so I called and asked Barry what the trick was? He said I was doing it right, to just use a screwdriver to pop it right off. Well, after I had pretty much destroyed the lid of the paint can, I figured out that you do it by sticking the screwdriver up under the ring on the SIDE of the can.....not on top of the can! I had to go down to Home Depot to buy a new gallon paint can to put 3 1/2 quarts I didn't use in! :BangHead: Dumbass!.......lol.
 
Since my post has been resurrected here is an update. I have been priming as work progresses and using PPG CRE epoxy. Weeks and even months later it sands beautifully. Sprays nice with a 1.7 tip and is very thick. I plan on using CRE for hi build as well for final blocking.
Reasonably priced and allows the use of one primer product start to finish!
 
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