Dupont corolar/ PPG compatibility

[Joe M.]

Dupont/ PPG paint compatibility questions

1 - About to paint a 61 vette with acrlyic lacquer. Dupont corolar epoxy primer was sprayed over the bare fiberglass and filler. My dupont guy can't supply enough maroon lacquer to do the whole car. Figure to switch to PPG and use their acrlyic lacquer line. I assume the dupont epoxy would be compatible with PPG K36 over the dupont epoxy primer and dp74 thinned as a sealer over the K-36. Alternatively I could use the Dupont Fill and Sand primer over the corolar and then seal with DP74 before topcoating with PPG lacquer.

2- Recomendation has been made for PPG application of DP74 over bare fiberglass followed with K36 and glazing compound where need and then followed by thinned out DP74 as a sealer as noted in the P sheet. Finally spray lacquer.
Is the DP74 sealer really needed over the K-36? Concern with overall thickness of the final paint.
Would the K-36 mixed as a sealer or thinned the same as for priming be sufficient prior to topcoating with lacquer?

Questions to PPG and autobodystore have gone unanswered to date.
I would be thrilled to receive some expert technical advice.

Appreciate your time.
Thanks!

Lacquer vs BC/CC arguments have been concluded.

[Chuck S.]

Re: Dupont corolar/ PPG compatibility

Joe, your questions have gone unanswered because no paint manufacturer is going to tell you that you can mix product lines successfully. The corollary to this statement is that there is no way you will have any warranty recourse from PPG if you end up having problems with their lacquer over DuPont primer.

On the other hand, people who paint professionally have probably been over this bridge before...if you get no good feedback here, you might try autobodystore.com "Break Room Board" (see link below).

Only one other bit of bad news I can give you: If you have to sand off that epoxy primer, you're in for a trial...I found that it's very hard paint, and labor intensive to sand...best results obtained with lots of fresh paper.




autobodystore.com "Break Room Board"

[John M.]

Re: Dupont corolar/ PPG compatibility

Joe,
I would not be concerned about the cured Epoxy under the K36 primer. I use the NCP271 primer, but that is just a personal preference. It is a corrosion resistant primer that is applicable to steel or Fiberglass bodies. I would just shoot the primer over the Epoxy and then the lacquer. Lacquer is lacquer and PPG lacquer is not going to be substantially different than Dupont. I have never seen the reason for a seal coat over a NCP271, and have shot both urethane and lacquer over it with excellent results. What Chuck says is true about the difficulty getting the manuf to accept responsibility when you mix products, but the ship has already sailed on that. It has been my experience that getting the manufacturer to accept responsibility for a failed paint job is problematical at best. I would not go to all the trouble to remove the epoxy primer.
Just my $.02

Regards, John McGraw

[Chuck S.]

Re: Dupont corolar/ PPG compatibility

John, in my mind there are questions regarding the proper prep of the cured epoxy. Careful study of DuPont's product sheet would be in order.

In the case of DP74LF, I don't think PPG recommends simply topcoating the epoxy with another PPG product after sanding. PPG recommends sanding the cured epoxy, spraying another coat of DP74LF, THEN top coating within a week's time. PPG's tech people told me nothing else would stick to DP but DP once it cured. Under those circumstances (wet on wet, no sanding), mixing product lines might be a problem.

I agree that removing the DuPont epoxy primer is bad idea, and to be considered only as an absolute last resort. Another option might be to continue with the DuPont by beating the bushes for the maroon lacquer. It seems like we have had theads here recently on sources for lacquer. It seems like one post said that a distributor was buying up the lacquer for internet sale? An archive search might be helpful in the search.

[Joe M.]

Re: Dupont corolar/ PPG compatibility

Really appreciate your responses. I'll try to continue with Dupont. My Dupont guy said the Hibernia auto restoration shop here in NJ had been buying up all the Dupont components. I'll give them a try and check the archives for other sources. My guy could mix up a gallon of maroon. I'm figuring I need 1.75 gallons. The underside of the trunk and deck lid has very clean and original paint and I just plan to touch it up, white coves save a few more ounces. I discussed wether he could mix the paint according to the formula or if he needs to scan a sample. Will have to revist that conversation. He emphasized it would be a big deal, not sure why. I've seen lacquer mixed via formula using a scale and it seemed quite easy but could leave room for poetic license if the mixer was not being real careful. I'll try to get one big batch, if not I'll combine the color from whatever sources I can, to ensure uniform color. Saw an odd shade of maroon on a 61 at Calrisle this year. I'm sure it was intended to represent the original color but was way too light. I got the impression it was BC/CC but that was just a guess. Wonder if that would explain the shading on that car in terms of available tints, scan generated formulas vs converted formulas?

Imagine trying to claim a guarantee on anything today, let alone paint.

Again, thank for you time.

[Wayne W.]

Re: Dupont corolar/ PPG compatibility

I agree with John. You can use most anything over cured epoxy or cured polyurethane. Mixing brands is not going to matter one bit. You must however thoroughly sand any epoxy before it is recoated after cureing. As for getting any warrantee out of a manufacturer, forget it. In 30 years, I have never gotten more than some replacement product out of one. Never any monetary restitution. It don`t happen often, if ever. They are a lot like trial lawyers. Before they are through, you will be the one at fault anyway.

[Dave F.]

Re: Dupont corolar/ PPG compatibility

Joe,

Try Kentucky Motors in Newport, KY., as they supply lacquer to the Greater Cincinnati paint shops. 859-655-6766, though the area code may be 513

[Joe M.]

Re: Dupont corolar/ PPG compatibility

Like a presidential candidate noted for flip-flopping, I guess I'll put the PPG K-36 over the dupont epoxy primer. Glaze where needed and then seal with reduced DP74 and shoot the PPG acrlyic. Talk about sticker shock $$. I make a couple more inquires re dupont.

This is the word I got from Hibernia Restorations. My Dupont guy said Hibernia was buying up Dupont components.

"DuPont is no longer in acrylic lacquer. The 1961 Corvette color code is 523 - Honduras Maroon Poly (metallic).

We can make the color in acrylic lacquer with a factory formula in PPG's chemicals. If you are doing an overall paint job, then the formula will be fine. If you plan on doing blend-in work, there is no color assurance for several reasons; one is that the paint is forty four years old assuming it is original, two is, has the car been repainted, three is, if the car now has DuPont paint on it, no other paint manufacturer's color will or can match the other's (PPG, R-M, Limco, Acme, etc., to DuPont).

Scanning a color is not a science that can be relied on. It is only for a database reference for a color that is within 'range', i.e., must be tinted and blended for any satisfactory results, if any at all.

The cost for the Honduras Maroon Poly in acrylic lacquer is currently at $445.00/gal plus UPS shipping and handling charges, unless you come up to pick it up yourself.

If you decide to purchase the paint, please call at 973-627-1882 for prompt service to place your order.

Thank you for choosing Hibernia Auto Restoration to provide services for you and your restoration project."

[Wayne W.]

Re: Dupont corolar/ PPG compatibility

Its sticker shock for all paints, not just lacquer. I just bought a gallon of Urethane with hardners and activators yesterday and it was over $450. I will have about $1000 in paint supplies in this car ( not a Corvette) before I am through.

[Dave F.]

Re: Dupont corolar/ PPG compatibility

Wayne,

Is this a recent cost increase for these materials? In my lacquer search last year for silverstone silver, I seem to remember the costs being a little less than half of what you had to just pay. Could it also be a regional variation in costs?

[Wayne W.]

Re: Dupont corolar/ PPG compatibility

It depends on the color, type of paint, activators etc. Lots of varibles, but yes, every time oil prices go up, paint goes up too.