Paint advice needed

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mopowers

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I'm prepping the jams and trunk on my '66 for paint and was wondering what product(s) would be adequate as a substrate for the 2K urethane single stage that I ultimately plan on shooting as a topcoat.

I'm not stripping the door jams completely but have sanded through to bare metal in spots. Can I use epoxy primer over these jams as a sealer before applying the single stage? All of the tech sheets for various epoxies that I've read seem to indicate that they can be used over "properly prepared factory finishes," but I've also read that using epoxy over enamel could be an issue. Weren't these cars covered in some type of enamel from the factory? Maybe I could rub some epoxy catalyst on a spot and see how it reacts?

Alternatively, could I just spot prime the bare spots with etch primer, then use a 2k urethane sealer, followed by the 2k urethane finish?

Short of stripping the paint completely (not gonna happen), what would you all recommend? Keep in mind this not a show car - not even close.

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I just spot prime bare metal areas with etching primer. I have never had a failure from it.
 
2nd etching primer. 2part etching primer if you can get it or a rattle can of good quality.
Syleng1
 
I just spot prime bare metal areas with etching primer. I have never had a failure from it.
Thanks Greg. I'm assuming once spot primed as needed, you just shoot a urethane sealer over that, or some type of 2k surfacer if body work is needed?
 
I like to shoot epoxy primer wait 30 minutes or so and go right over it with 2K single stage let the two layers of paint flow out together as they cure. I tend to get a smoother shiner finish that way.
 
I like to shoot epoxy primer wait 30 minutes or so and go right over it with 2K single stage let the two layers of paint flow out together as they cure. I tend to get a smoother shiner finish that way.
What's your go to epoxy? Have you had any issues with using it over the factory paint?
 
I've been using SPI epoxy primer as sealer before base coat or single stage. Just thin it out with slow urethane thinner after mixing it with the activator. It works great. Just let it flash off for the proper amount of time, or just make sure you top coat it with your color within the recoat window of time. I love SPI's primers and Universal clear. Good luck to you!
 
I've been using SPI epoxy primer as sealer before base coat or single stage. Just thin it out with slow urethane thinner after mixing it with the activator. It works great. Just let it flash off for the proper amount of time, or just make sure you top coat it with your color within the recoat window of time. I love SPI's primers and Universal clear. Good luck to you!
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Thank you. I read their tech sheet earlier today. I'll have to give them a call on Monday because it doesn't say anything about applying their epoxy over OEM paint. Have you had any problems applying their epoxy over the factory paint on these old Mopars?
 
None, but I clean the heck out of surfaces before spraying any paint. The problems of the old days with lacquer/enamel reactions are pretty much gone. Unless someone repainted a Mopar with lacquer way back in the day, that problem shouldn't arise. I'm not a professional painter, but I have enough experience to do my own stuff. A month or so ago, I painted a 97 S10 bed for a buddy. The bed I swapped onto his truck had 47 coats of various colors of repaints on it, so I stripped it down to it's original red, cleaned it with water based wax & grease remover and then solvent based wax & grease remover and then sprayed a coat of SPI epoxy on it. Came back the next day and tacked it off and sprayed 2 coats of SPI 2K high build on it. The bed was straight to start with, so I blocked it good, cleaned it with both W&G removers again and sealed it with the same epoxy from SPI, but thinned out to go on slicker. Came out the next morning, tacked it off and painted it GM Emerald Green with base/clear. It turned out nice for a quicky job.

If you buy some epoxy from SPI, spend a few extra bucks and get both kinds of their wax and grease remover. Don't use cheap lacquer thinner from Lowes or Home Depot to clean with. I haven't had a fish eye since I started using real wax & grease remover. Look on You Tube and find Paint Society's channel. Brian can make stuff make sense! I've learned a lot by watching his videos.
 
This car, painted in 2003....

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Had metal etch primer, high build primer, PPG Deltron base and PPG 2002 clear. For a 20 year old paint job, it has held up well.
NO epoxy, NO sealer either. The use of sealer gained popularity after mine was painted.
Some people err on the side of caution with paint products. I understand that they are cautious and don't want peeling, lifting, cracking, etc but mine was painted without the stuff some people think are absolutely necessary and the car looks fine.


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I agree with the spi! I used their epoxy and universal clear im very happy with it. I did my door jams and engine bay and it turned out great. I gotta finish the rest of the car still!

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I agree with the spi! I used their epoxy and universal clear im very happy with it. I did my door jams and engine bay and it turned out great. I gotta finish the rest of the car still!

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Thank you. Did you spray the epoxy primer directly over the prepped original finish, or did you completely strip it down to bare metal?

This car, painted in 2003....

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Had metal etch primer, high build primer, PPG Deltron base and PPG 2002 clear. For a 20 year old paint job, it has held up well.
NO epoxy, NO sealer either. The use of sealer gained popularity after mine was painted.
Some people err on the side of caution with paint products. I understand that they are cautious and don't want peeling, lifting, cracking, etc but mine was painted without the stuff some people think are absolutely necessary and the car looks fine.


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That's what I'm figuring. Heck, when we painted my dad's Ranchero years back, we used rattle can primer as we body-worked panel by panel. Then, the paint shop sprayed over that. It looks the same as it did the day it was sprayed 25 years ago.

Do you have idea what type of paint these cars had originally? Was it an acrylic enamel?
 
Epoxy primer, then topcoat is the best choice. I like to use PPG DP epoxy, or Omni MP epoxy. You can reduce either a bit to make them spray out, and lay down easier.

Self etch primer is very misunderstood and often used incorrectly.
When a car body panel is sanded to bare metal, it is effectively somewhat polished. Same with brand new bare metal. So the factories use a phosphoric acid bath to etch the metal, so that the primer adheres to the metal well. This process was referred to as Bonderizing back in the day.
It used to be normal practice for body shops to use Metal Prep before spraying primers on bare metal. Metal Prep is a phosphoric solution that etches the metal. But this step was often overlooked and eventually got skipped altogether by many shops. However, it really is an important step. Self etch primers were developed to make it a simpler process. I'm old enough to remember using Dupont Corlar self etch primer, that had its catalyst in a glass bottle! Self etch primers contain a small amount of acid in them, which etches the metal a tiny amount. So on shiny bare metal, this is beneficial, but on old painted surfaces, it is pointless. Self etch primers should not be used on sandblasted metal. Sandblasted metal is rough, and somewhat porous on the surface, which provides lots of adhesion for the epoxy primer.
For best results and long lasting repairs, body filler should be used on top of epoxy primer, then sealed again with epoxy primer.
A top quality epoxy primer like SPI, DP or MP, is one of the key items to having a quality body and paint job, in fact, maybe even the most important.

Most body fillers are polyester based, and cannot be put over etch primers, or metal prepped steel, because the acid will react with the filler and cause major issues down the road.

Etch primer is really intended for bare metal spots only

So simply put, epoxy primer can be used over almost any clean surface, it adheres exceptionally well, and seals what is below. Single stage paint adheres very well to the epoxy primer.
 
Another way to explain it is that the bond that any paint or primer has is either chemical or mechanical...hopefully both.
Chemical is where the components bind to the existing surface like an adhesive.
Mechanical is where the surface is roughed up so the paint/primer/clear has something to grab, like a tire tread to the road surface.
 
I trust epoxy primer more than any other primer when painting over anything that seems sketchy. I've painted over factory and respray paint with it and I've yet to have a failure but I've only done this about 3 times so far. It's always a crap shoot but I don't think the odds are high that you're going to have an issue either as long as you prep it correctly. I personally wash with Dawn soap, then use wax and grease remover and then hit it with 70% isopropyl alcohol and a tack rag before spraying epoxy. No issues so far.

You may have issues with the manufacture approving you to paint over anything other than what they recommend because of liability reasons.
 
I trust epoxy primer more than any other primer when painting over anything that seems sketchy. I've painted over factory and respray paint with it and I've yet to have a failure but I've only done this about 3 times so far. It's always a crap shoot but I don't think the odds are high that you're going to have an issue either as long as you prep it correctly. I personally wash with Dawn soap, then use wax and grease remover and then hit it with 70% isopropyl alcohol and a tack rag before spraying epoxy. No issues so far.

You may have issues with the manufacture approving you to paint over anything other than what they recommend because of liability reasons.

Thank you. I appreciate the input. I think I have a plan now. I've got some areas like the inner deck lid that are mostly bare metal with some small spots of factory paint. I'll likely shoot some epoxy over those areas. Then there are windhsield and back glass channels where I've cleaned and scuffed to prep for paint and have spot primed any sanded-through spots with etch primer. I'll use a urethane sealer over those, then shoot color over each.

Any idea how much single stage paint I'll need for a trunk, inner deck lid, door jams (body and doors), and windhield/back glass channels? Will a quart suffice, or should I get two to be safe? I have no idea. The color will be WW1 white, going over gray epoxy/sealer.
 
I buy from Mac's distributing on Auburn Blvd. They have been fair to me for well over 20 years.
It really is best to buy more than you think you'll need. Running short while doing a job really sucks!
I did a '74 Duster 360 with a gallon of Omni.....The paint was so transparent I had to go 5-6 coats in some areas to cover the primer spots. I didn't have enough to respray the trunklid where I color sanded through. I was already too far into the car at that point and sold it for less than it was really worth. I just wanted to be done with the car.

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I buy from Mac's distributing on Auburn Blvd. They have been fair to me for well over 20 years.
It really is best to buy more than you think you'll need. Running short while doing a job really sucks!
I did a '74 Duster 360 with a gallon of Omni.....The paint was so transparent I had to go 5-6 coats in some areas to cover the primer spots. I didn't have enough to respray the trunklid where I color sanded through. I was already too far into the car at that point and sold it for less than it was really worth. I just wanted to be done with the car.

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That's where I'll be buying my stuff from. They're really helpful there, which is nice for inexperienced folks like myself. Do you spray yours in your shop, or do you wheel them outside to spray them?
 
I set up a plastic sheeting "curtain" inside the shop. I attach it to the roof trusses and leave at least 8 feet around the car to work and move.
I try to paint between 65-95 degrees.
Under 65, the paint doesn't flow out that well and takes too long to dry. Over 95, the paint dries too fast and makes for "peaks and valleys" in the topcoat requiring much more color sanding to get it all to look right. The standard 50% overlap on each pass is supposed to flow together to result in an even finish. Drying too fast makes the edges of the spray pattern stay high instead of flattening out.
Mac's.....
Chan is the Asian guy. Really cool dude. Tyler is mid 30s, thin, brown/reddish hair and also great. They have a few others that work the counter part time that are all friendly but in my opinion, Chan and Tyler are the top guys.
 
I set up a plastic sheeting "curtain" inside the shop. I attach it to the roof trusses and leave at least 8 feet around the car to work and move.
I try to paint between 65-95 degrees.
Under 65, the paint doesn't flow out that well and takes too long to dry. Over 95, the paint dries too fast and makes for "peaks and valleys" in the topcoat requiring much more color sanding to get it all to look right. The standard 50% overlap on each pass is supposed to flow together to result in an even finish. Drying too fast makes the edges of the spray pattern stay high instead of flattening out.
Mac's.....
Chan is the Asian guy. Really cool dude. Tyler is mid 30s, thin, brown/reddish hair and also great. They have a few others that work the counter part time that are all friendly but in my opinion, Chan and Tyler are the top guys.
Yep! Both of those guys are the ones I've been buying from. Talked to Tyler on Friday and got my order going for this project to be picked up tomorrow. Thanks for the tips!
 
Thank you. I appreciate the input. I think I have a plan now. I've got some areas like the inner deck lid that are mostly bare metal with some small spots of factory paint. I'll likely shoot some epoxy over those areas. Then there are windhsield and back glass channels where I've cleaned and scuffed to prep for paint and have spot primed any sanded-through spots with etch primer. I'll use a urethane sealer over those, then shoot color over each.

Any idea how much single stage paint I'll need for a trunk, inner deck lid, door jams (body and doors), and windhield/back glass channels? Will a quart suffice, or should I get two to be safe? I have no idea. The color will be WW1 white, going over gray epoxy/sealer.

Sounds like a good plan. I wish I could help better with the amount of paint needed because I struggle with that myself. I feel like a quart would be fine but the trunk seems to take more paint than you might think. If you're going with the Shop Line paint that Mac's sells, I've only used the base/clear from that line before but I do remember it not covering well at all and not really being a money saver since I had to use more material. Not sure if their single stage covers better though.

I've been happier with base/clear from the coating store and single stage from TCP Global. Always better to help out local jobbers if you can though. The Asian guy that Kern talked about helped me out there a couple times and was very helpful. Good dude.
 
When I do the jams, engine compartment, bottoms of hood and decklid, trunk and interior floor pans of my 65 Barracuda, I will buy a gallon of single stage urethane. I'll do the interior floor pans last in case I run low on paint at that point. I want the stuff that will show to look nice and shiny, but as long as I get some color on the floor pan....that will be good enough. Carpet's gonna hide it anyway!
 
Thank you. Did you spray the epoxy primer directly over the prepped original finish, or did you completely strip it down to bare metal?


That's what I'm figuring. Heck, when we painted my dad's Ranchero years back, we used rattle can primer as we body-worked panel by panel. Then, the paint shop sprayed over that. It looks the same as it did the day it was sprayed 25 years ago.

Do you have idea what type of paint these cars had originally? Was it an acrylic enamel?
I sanded everything down not completely to bare metal but mostly. The there was some old primer left. I would sand it down at least to primer. There was a couple spots like the hood hinges that I sprayed over the old paint without sanding and it is peeling already. Spi has a spec on what the preped surface should be sanded too but I can't recall off the top of my head.
 
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