Primer

[btceng]

What effect does the primer color have on the final color? Also, I am working along slowly and need the ability to prime panel sections at different times. I'm not sure if the rattle can primers offer sufficient protection to paint over for a quality long term paint job. I like the idea of using the black 2k epoxy from Eastwood but have no experience with it or any other 2k primer for that matter. I've been told to use nothing without a hardener/catalyst. Please advise.

 

[AlleyoopMgv]

Yeah, you heard right. If it doesn't have a hardener, don't use it! If your looking for a good quality paint job, then I wouldn't use anything in form of a spray can. I use mostly PPG products, so I would recommend K38, K36 or something to that effect.

R-M or BASF has a great primer also.
I'm sure that Eastwood primer would be pretty good, if it has a catalyst.

Whatever primer your going to use, just try and get a neutral color like gray, and then you won't have to worry about effecting the color.

When I restore a car, my last go-around of primer, I tint the primer to come as close to the color as possible. If you get a rock chip in the car it's not as noticeable by doing it that way. But by no means do you have to do this.

This car is C7 Plum Crazy, and I tinted my primer.

 

[btceng]

Thanks again for all of your great advice. That makes a lot of sense. I have never painted a whole car before but I really want to "do it all" on this one. I have the front clip apart now and have to put a patch panel in on the lower right quarter. I have a significant amount of rust inside of the fender reinforcement (?) channel near the bottom of the panel. The part near the lower bolt area near the door.

How do you treat rusty areas inside of these channels on the back of panels or inside the drain area on the firewall cowl? I have been using the Eastwood rust converter but I'm not sure how to get it into those "inaccessible" areas. They make a sealer/encapsulator that has a hose and nozzle for getting into frame rails and the like. The rust is barely visible from the front of the panel but I know that if left untreated, it will soon bubble through.

Epoxy primer followed by high build? Do I really need the epoxy? My son is now pushing for Sublime. I'm starting to lean that way also.

 

[ramenth]

Getting into those inaccessible areas can be a nightmare. I'd say anything you can do to put a rust converter in there, like the Eastwood product you're speaking of, will help.

I'll agree with Alley on the primers. Stay catalyzed at all times. And stay away from spray bombs (or rattle cans, as some folks call 'em) unless you feel like doing it all again in a few months time.

As for epoxy, I'll diverge from most of my peers. I haven't used it for years. For me it's an unnecessary step and a wasted expense. PPG's NCP 270/271 has excellent corrosion hold out (equal to that of epoxies) and since it's a surfacer it covers like a bear. Unreduced I use it like a sprayable glazing putty.

I expect to get flamed by the epoxy purists (I always do) but I won't go back.

 

[btceng]

Thanks guys. Can you recommend an economical gun for spraying the primer? I have a HF but it only has a 1.4 tip. A little small for primer, I think. A 1.8-2.0 tip is better, right?

Also, I get differing opinions on whether to go down to bare metal or not. The paint on my car is in pretty good shape for the most part but it has both the original (Y4, yuck!) and a second beige color over that. I've been using a DA with 120 grit to address the known problem areas but my intent is to spray over the rest of the car without taking to the bare metal. I have plenty of time and paper, though. What's best?

 

[AlleyoopMgv]

Well it's always best to go down to bare metal, you don't have to, but if it's got a couple of paint jobs on it, and you got the time, why not. I'm sure you know this, but I have to say it " be careful you don't warp your panels" using a DA, heating up the metal.

As far as a cheap spray gun, you can get one anywhere, Tractor Supply Company, Fleet Farm, Menards, etc.............. it doesn't have to be expensive to work. You can buy a cheap primer gun for about $35-$45 bucks
Try to get one with at least a 1.7 tip

When it comes to painting your car, try not to skimp on that spray gun though. I mean you don't have to pay $500 bucks for a gun, but you can get a decent gun for around $150 or so.

 

[btceng]

I have been looking at the Devilbiss Starting line set with the 3 guns but a cheap TPC Global set gets as good or better reviews. I mean they are both inexpensive but the TPC one has 3 guns for $80. The HF gun that I have sprays pretty good but the 1.4 tip makes thick primer a slow process. I do have plenty of cfm and I think that I could use any.

Thanks ramenth for the info on the PPG NCP. I have found more good info and testimonials on that product. It does seem pricey but I guess as always, you get what you pay for. A data sheet on gun selection from PPG says that a 1.4 tip can be used for this stuff but I find that hard to believe for a high build primer.

Happy New Year all!

 

[btceng]

Alley...I know about the heating of the panel and I am careful in trying to avoid it. In the case of not having access to a blaster, what is the best method of removing the old paint. I have never tried the aircraft remover or any other chemical remover. I had thought about using a high speed sander with 36 grit but the heat issue would seem to be harder to avoid.

 

[AlleyoopMgv]

Devilbiss Starting line guns are pretty good guns, I've had a few in the past, but I would go with the TPC Global set myself.

At the Chrysler dealership that I work at we use NCP 271, and it's a good primer, but I use a 1.7 tip gun with it.

I've stripped cars both ways, aircraft stripper works the best, but it's messy, and you got to make sure you get it out of all the cracks and crevasse's before you move on.

As far as sanding it off, I'll start of with a mud hog with 80 grit and then to a DA with 180 grit, just keep moving it around, don't keep it in one spot to long, and you should be ok.

 

[ramenth]

Well it's always best to go down to bare metal, you don't have to, but if it's got a couple of paint jobs on it, and you got the time, why not. I'm sure you know this, but I have to say it " be careful you don't warp your panels" using a DA, heating up the metal.

As far as a cheap spray gun, you can get one anywhere, Tractor Supply Company, Fleet Farm, Menards, etc.............. it doesn't have to be expensive to work. You can buy a cheap primer gun for about $35-$45 bucks
Try to get one with at least a 1.7 tip

When it comes to painting your car, try not to skimp on that spray gun though. I mean you don't have to pay $500 bucks for a gun, but you can get a decent gun for around $150 or so.

Gonna agree with Alley here on all counts, especially about taking it down to bare. If it's a got a couple of paint jobs on it already and you have the time, now might be the best time you've spent on taking it down. Who knows what be might lurking under that last job...lacquer based primers, which will never hold up? Filler that wasn't properly applied over some door dents? Going to bare will give you the piece of mind of knowing what's under your paint.

He's also dead on about the guns. A good primer gun, with the right tip and cap isn't something you have to go out and spend a lot of money on. Just as long as you get enough material out the tip and good atomization from the cap, you're golden.

But do spend the money on a good gun for paint application.

I have been looking at the Devilbiss Starting line set with the 3 guns but a cheap TPC Global set gets as good or better reviews. I mean they are both inexpensive but the TPC one has 3 guns for $80. The HF gun that I have sprays pretty good but the 1.4 tip makes thick primer a slow process. I do have plenty of cfm and I think that I could use any.

Thanks ramenth for the info on the PPG NCP. I have found more good info and testimonials on that product. It does seem pricey but I guess as always, you get what you pay for. A data sheet on gun selection from PPG says that a 1.4 tip can be used for this stuff but I find that hard to believe for a high build primer.

Happy New Year all!

You're welcome on the tip about the NCP. I've been an advocate on this primer for a while now.

Just remember the P-sheet is a guide, not gospel. PPG has millions sunk into R&D and most of the time it's good, but not great, for those of us spraying out in the field, so to speak. They have perfect air supply, perfect temps, perfect humidity. I've never worked in a perfect shop, so I've learned to read my conditions and adjust accordingly. I run it with the 1.7 tip like Alley suggested, unreduced.

Just a couple of warnings about the NCP, though, if you go that route. Use the 271. It's a neutral gray. Also, as soon as you're done, clean the gun! The higher the temp, the quicker it sets. You've got about a 2 hour window to use it once it's mixed. Trust me, you don't want to let it harden in the gun.

 

[ramenth]

Devilbiss Starting line guns are pretty good guns, I've had a few in the past, but I would go with the TPC Global set myself.

At the Chrysler dealership that I work at we use NCP 271, and it's a good primer, but I use a 1.7 tip gun with it.

I've stripped cars both ways, aircraft stripper works the best, but it's messy, and you got to make sure you get it out of all the cracks and crevasse's before you move on.

As far as sanding it off, I'll start of with a mud hog with 80 grit and then to a DA with 180 grit, just keep moving it around, don't keep it in one spot to long, and you should be ok.

You read my mind, Alley. I was about to suggest all the above! lol

 

[btceng]

What is a mud hog. Is that a low speed sander/polisher? Also, my car has what looks to be factory undercoating. Do I remove this? It's in really good shape and hard to remove even with a wire cup on my angle grinder.

I have to work off of the floor and jack stands and I can imagine the trouble in removing all of the undercoating. My frame rails, floors, and wheelhouses are very solid. The factory seam sealer is falling off almost everywhere. The seams under the sealer looks good with the exception of some light rust which why the sealer let go, I assume.

Thanks guys.

 

[ramenth]

What is a mud hog. Is that a low speed sander/polisher? Also, my car has what looks to be factory undercoating. Do I remove this? It's in really good shape and hard to remove even with a wire cup on my angle grinder.

I have to work off of the floor and jack stands and I can imagine the trouble in removing all of the undercoating. My frame rails, floors, and wheelhouses are very solid. The factory seam sealer is falling off almost everywhere. The seams under the sealer looks good with the exception of some light rust which why the sealer let go, I assume.

Thanks guys.

A mud hog is basically a larger DA. Usually takes an 8" pad. It's good for working over larger surfaces.

I'd say as long as the factory undercoating - and more importantly the panels underneath it - is in good shape, I'd leave it.

The seam sealer letting go doesn't surprise me. A lot of times the factory didn't prime under the sealer. Scrape it up, prime underneath it, and lay down some better seam sealer.

 

[btceng]

As usual, you are right. The seams are like new metal under the old sealer. Getting closer to needing that primer. Will that NCP271 kill rust in those hard to reach areas or do I need to try to stop it chemically? How many coats before sanding? I assume 2-3.

I have the windshield and back glass out but the door and quarter glasses scare me. How hard are they to deal with? Remove doors or not? Only rusted on bottom. Not bad.

Sorry for the bombardment of questions. I am beginning to feel ill-equipped. I'm having to learn as I go. Thanks.

 

[ramenth]

As usual, you are right. The seams are like new metal under the old sealer. Getting closer to needing that primer. Will that NCP271 kill rust in those hard to reach areas or do I need to try to stop it chemically? How many coats before sanding? I assume 2-3.

I have the windshield and back glass out but the door and quarter glasses scare me. How hard are they to deal with? Remove doors or not? Only rusted on bottom. Not bad.

Sorry for the bombardment of questions. I am beginning to feel ill-equipped. I'm having to learn as I go. Thanks.

The NCP doesn't "kill" rust, but it has some excellent hold out against rust on clean panels. You'll need to chemically convert what's there before laying down primer.

Hard to reach areas? Like under the package tray in the trunk? Into the seams? Do you're best to get it clean either through chemical means or mechanical.

Quarter and door glasses are bolt in affairs. If you can pull a panel like a fender, you can get these out, too. It's all just nuts and bolts and not that hard.

As far as taking the doors off that's up to you. If you think you can take care of the rust without taking them off, well, again, that's your decision. Personally, I always take 'em off just so I can get to those hard to reach areas, prime 'em up, and put 'em back on. Some guys like to take that opportunity to paint the edges and jambs, too.

As far as the questions go, it's a forum. That's what it - and we - are here for.

 

[AlleyoopMgv]

I usually paint the cars I do with the doors, hood, fenders, and trunk lid off the car so there is no tape lines, and so you can get the fronts of the doors and doors jambs better.

Just remember one thing, there's more then one way to restore a car, just because people do it different doesn't mean your doing it wrong.

 

[ramenth]

Just remember one thing, there's more then one way to restore a car, just because people do it different doesn't mean your doing it wrong.

That's the best thing I've read.

 

[btceng]

I would like to pull the doors off because I know that it would make for a better paint job and make it easier to get good coverage. I worry about getting the alignment right in the final assembly. I assume it's best to remove the door from the hinge and not the hinge from the car.

 

[btceng]

I went to my local paint store (PPG) today and bought some primer. Not the NCP. He said that he only has one customer that uses it and that it was expensive ($228 a gallon). He suggested Shopline epoxy which comes in quarts which is what I bought. He suggests the epoxy followed by 2 coats of high build unreduced.

Also, picked up a set of guns (ATD 6100) that has a primer, base, and detail gun. A cheap set that he says suits most walk-ins that purchase them. Do I use filler before or after the epoxy? I assume before on clean scuffed metal.

Thanks guys for making me feel comfortable enough to do this.

 

[AlleyoopMgv]

I would like to pull the doors off because I know that it would make for a better paint job and make it easier to get good coverage. I worry about getting the alignment right in the final assembly. I assume it's best to remove the door from the hinge and not the hinge from the car.

Yes, try not to take the hinges off the car body, it will make putting the doors back on much simpler. When you put the doors back on just run a couple of strips of masking tape along the front door edge and the back of the front fender edge. Also drape a blanket over the front of the rocker in the door jamb.