C! Paint: PPG?

[Robert Binder]

I have a 55 Vette that I am in the process of restoring. It is in the paint shop now, and I would like some help in determing which paint would be best to use. My paint shop uses only PPG paint, so I'm going to have to use it. My question is: Can I make the base coat, clear coat look original, or should I go with a single stage Urethane? I don't want to use Laquer because I don't think it would be durable enough.

Robert Binder

[Stephen W.]

Re: C! Paint: PPG?

PPG is a quality paint product and especially if this shop is using the product I would stay with it. If it's a solid color then I would prefer to use a single stage because it would be the best match. And depending on how the vehicle will be used I have no problem with a quality lacquer product. I will not put anything else on my '68 British Racing Green. It's the only way to achieve the real look for the car... But I also painted lacquer for 16 years before going to work for RM Inmont ( BASF). That was right at the changover time when the shops had to convert to BC/CC systems to keep pace with the industry.

[Chuck S.]

Re: C! Paint: PPG?

Robert, there are steps that can be taken in the painting process to make acrylic urethane finishes "appear" as acrylic lacquer. One such step is to flatten the paint sprayed in the door jamb and gutter areas such that it appears as un-polished lacquer as done at the factory. Spraying technique, and mixing color with the clear, can also be part of the process.

These techniques are offered as a training seminar at NCRS regional meets and the national conventions on a regular basis. The content of these seminars was also published in the The Corvette Restorer magazine. Highly experienced paint judges say they can identify modern finishes; other experienced paint judges say modern finishes can be made to appear as lacquer. In judging, you may have some deducts if the exterior team is experienced with very high standards. My observation is that paint on restored cars is almost ALWAYS over-restored, but that doesn't seem to keep them from Top Flight.

The PPG system recommended to me by experienced painters on this board was: DPLF epoxy primer on the bare prepped fiberglass, K36 primer-surfacer, reduced DPLF as a sealer, DCU acrylic urethane single-stage color, and if desired, DCC clear. Color should be mixed into the clear, about 50% if I recall correctly, to reduce the obvious BC/CC look.

The DPLF primer/sealer comes in several colors: DP74LF is close to the factory red oxide primer, DP50LF is grey similar to some sealer coats, and DP90LF is black. The advantage of using the single-stage DCU is that you receive a durable finish that can stand up to the elements without clear, but additional durability can be obtained by top-coating it with clear.

[Robert Binder]

Re: C! Paint: PPG?

Thanks for the advice Chuck. I have talked to others about adding the color back into the clear, but we talked to the PPG paint supplier and he said that he wouldn't recommend it. Something about the base particles settling out. I still think that that is the way that I want to go. Do you recall how long ago the article appeared in the restorer?

Thanks again, Robert

[Stephen W.]

Re: C! Paint: PPG?

As a former paint rep I would agree with the PPG rep about mixing the color with clear. If you look at the formula for any color it's made up several colors some of which are "strong" or opaque and others are tints or transparent. My concern about using a 50/50 mix is throwing the color off by having pigments suspended in a clear and having a base of the "actual" solid color. It may produce a deeper shine or greater depth of color but under certail conditions could result in an unwanted appearance of a clowdy cast or depending on the pigments result in a different color. I have used the primers and sealers mentioned here and was very please with the results. Like I said earlier I would stay with the single stage for your color. My preference for lacquer has to do with a personal desire for the lacquer look as well as easier application in my garage. I also prefer the ease of spot repair should I get a nick or chip in it. Lacquer will reflow and meld to become one finish therefore resulting in an undetectable repair ( without the use of clear or Buffer coats). Urethanes are more durable finish and will resist chiping better as well as enduring the expansion and contraction of the body( stress cracks and checking) but by their very nature are more difficult to repair. Panel painting , adhesion promoters and clears are usually needed for repair.

[Chuck S.]

Re: C! Paint: PPG?

Robert, I made a mistake in the PPG formula names in my previous post: I should have said DCC Concept color, and DCU2021 Concept clear.

In response to your paint supplier's comment, I would say he should read PPG Product Bulletin P-168 for DCC Concept color...it specifically instructs the user on mixing clear in the final coat of color. You can find the bulletin at the AutoBody Depot Link below.

In the case of metallics, your supplier's concern may be warranted. For metallics, you would need to check with Tom Ames, the usual presenter of the paint seminars. I know for sure that Tom is presenting a paint seminar at the Texas Regional in Waco (November 4-6)...this topic may be past interest to you by that time, but if you are close enough, drop on down.

I have mixed clear in the final coat of solid color DCC, but I can't say what effect it had on depth of color since I did no "color only" samples for comparison. My estimate of 50% color/clear is based on my sometimes-faulty memory...check The Corvette Restorer article to confirm the ratio. Remember, with DCC, the use of clear is optional: if you want superior endurance you can use the clear without mixing in color, but then you will have paint that looks great and just like BC/CC...if you want a finish that will approximate acrylic lacquer more closely to the experienced eye, you can always skip the clear altogether.

The paint article was written by Tom Ames, and is in the Spring 2003 issue of The Corvette Restorer, Vol. 29, Number 4, page 33.




AutoBody Depot Product Bulletins

[Robert Binder]

Re: C! Paint: PPG?

That's great information Chuck. I will give it to my paint shop Monday. I read the article by Tom Ames, and I didn't see anything about the amount of color in the clear. I've had two people tell me they have used 15% and 25% on their cars. I wish that the product bulletin would have given more detail on the percentages that could be used.

Thanks again, Robert

[Chuck S.]

Re: C! Paint: PPG?

Actually, Robert, I heard the suggestion for mixing color into the clear coat at the Galveston National (2001?) paint seminar. Sorry for misleading you; it's been awhile since reading the article, and I "assumed" that the article covered the same material as the seminar.

Tom Ames' contact info is at the end of the article; if you have questions about the article, I would contact Tom directly. PPG also has tech center personnel in Strongsville, Ohio to help customers, but they are primarily oriented to problems encountered in applying their products...from my experience, they may not be able to help you with technical questions about their products if you get off their well-worn path.

[Patrick F. McInerney]

Re: C! Paint: PPG?

This thread has been most helpful to me. In early August I posted about my '64 paint disaster and have been trying to get as much tech paint detail together as I can. The PPG Tech Center sent me a bulletin on fiberglass painting which closely resembles the bill of material in the thread.
Having now learned that my unsuccessful painter had not used epoxy primer or sealer and compounded the problem by mixing various manufacturer's paint products I am forced to strip the body for a second time. Before getting involved with another painter and running the risk of another disaster I need to know materials, sequences and procedures. Is there a book or pamphlet that you can recommend?
Thanks for your help.

Pat McInerney

[Chuck S.]

Re: C! Paint: PPG?

Patrick, my thought is that any book or pamphlet will deal only with only very basic information and generalities. If you are just starting out, then something like that will be helpful.

In answering Robert's question, I ran across a little book I had forgotten I owned: Painting Your Corvette, was written by anonymous author(s) and published by Mid-America in 1985. The chapters deal with choosing proper equipment (surely out-of-date unless revised), stripping/prep/priming the body, painting the color coats, and how to do body repairs. It also includes some charts on paint failure trouble-shooting, and Do's and Don'ts. It's pretty basic and it's brief...but, then it only cost $6.00 in the early nineties.

Your best information is going to come from studying the PPG product bulletins, but there are so many of them that it helps to have a recommended system as a starting point. There are a lot of little pit falls you have to be aware of in using PPG products: for example if DPLF epoxy primers are used over existing lacquer, you have to get the DPLF top-coated with at least one or more coats of another product, and preferably take the process all the way through to the clear to prevent DPLF from lifting. (Whoever came up with that suggestion was insane; it's physically impossible unless you have shifts of painters and prep guys working on the project.)

I would be interested in what products PPG's Tech Center told you to use for painting fiberglass if you would like to post that info.

[Patrick F. McInerney]

Re: C! Paint: PPG?

I'll paraphrase PPG just a bit.

Strip paint down to gel coat but do not remove. Neutralize by washing with soap and water. Wipe with DX330 wax and grease remover.
Sand surface with 180 to 220 grit paper and wipe again with DX330. Apply 3 coats K36 primer surfacer mixed 5 to 1 of K201 hardener allowing proper flash time between coats. Allow finish to cure at least 16 hours then apply a thin guide coat of black or gray primer to check for low spots or otehr imperfections. Block sand with 180 to 220 grit paper. Re-apply 2 coats of K36. Block sand with 400 grit. Re-apply 1 coat K36 mixed 5 parts K36, 1 part K201 and 1 part DT870.
Wipe again with DX330. Apply DBC base coat color until full coverage is achieved, usually 3 coats. Apply DCU clear coat of your choice. Allow clear to dry prescribed amount of time and lightly sand with 1500 to 2000 grit. Buff with foam pad and a compund such as 3M Perfect-it-III to remove scratches.
I assume that the gel coat, which was not applied by GM at manufacture of '64,
is replaced by use of epoxy primer.
I want to understand the process, materials, timing, etc to be able to discuss procedure with the next painter and elimnate trouble before it happens.
Thanks for your response.

Pat McInerney

[Chuck S.]

Re: C! Paint: PPG?

Thanks for the excellent info, Patrick; I'm printing it.

The only question I have is you indicate no sanding or sealing of the K36 just prior to applying the DBC...is that an omission or did they really say to do that? The product bulletins typically say it is best to seal the K36, and K36 usually has to be sanded to get adhesion.

If this sounds arrogant, I apologize, but I'm convinced most painters in the world are not cerebral guys...they're just trying to make a living. Keeping abreast of fast changing paint technology is challenging for them because it requires reading, a distasteful activity requiring time they could be using to drink beer or watch TV.

Unless a paint rep keeps it simple and tells them orally how to use these new paint products, many are underinformed, and some are downright catastrophes waiting to happen. I knew you were going to have to strip that car (particularly if you talked to PPG), but I couldn't come right out and say that I absolutely knew the last word...I truly do feel your pain.

[Patrick F. McInerney]

Re: C! Paint: PPG?

I did overlook one sentence in my outline of the PPG Tech Paper. It reads before applying base coat color " Sand with a 3M hand sponge pad and 600 grit wet paper." Sorry for the omission.
Thanks for your commiseration. I've decided that many painters have inhaled the fumes too long and float about a foot off the ground.

Pat McInerney