Automotive Paints

This month’s question comes from Wendell Nobel:

Dave, I would love to read a little dissertation on automotive paints. I recall a day when GM cars were all painted with acrylic lacquer and Fords were acrylic enamel. Now we have polyurethane base coat with clear coat, single stage urethane and even some water based stuff. What is an antique car guy to make of it all? Should we use what was on the car when new or get up to date? Will environmental laws make the question moot?

Let me first briefly explain the history of automotive paints. The early autos were painted with the same paint people had been painting carriages with for years. There was no “automotive” paint. Not paint in the traditional sense we think of when we talk about paint today. Early paint was basically linseed oil and a binder, with pigment, or crude shellac. This paint was applied with a brush and took a long time to dry. These paints were not very durable, often literally falling off the metal in a year or two. These finishes offered very little U/V protection and broke down quickly.

The biggest challenge with producing the Model T Ford and other early cars was the time and space needed to paint cars. The parts were laid out on the floor and took days to dry. This bottle neck in the production was a huge problem.

Nitrocellulose Lacquer paint was developed to alleviate the time/space problem. Nitrocellulose Lacquer paint is made from the nitration of cellulose plants (boiling down plant fibers and mixing with nitric acid). This is also how celluloid film was made. The solvents evaporate from the paint, leaving a glossy durable paint finish. These paints need to be “rubbed out” to produce a shine. This paint does not “cure” and will return to a liquid state when solvents are applied. A popular early nitrocellulose lacquer paint was DuPont “Duco” paint.

Nitrocellulose Lacquer dominated the automotive paint market from the early 1920s well in to the 1950’s when it was displaced by Acrylic Lacquer, a synthetic polymer acrylic resin based lacquer. Acrylic Lacquer dried quickly, however, still needed to be buffed to a high gloss.

Enamel paints used enamel resins. This type of paint takes much longer to dry than lacquer and actually dries in two steps. First, the enamel reducer evaporates and the paint becomes solid. Next, the resin oxidizes when it reacts to the air. This is why the new finish cannot be waxed for 30 days after application. The enamel paints dry to a hard, glossy finish and do not need the rubbing out as lacquer needs. The drying of enamel paints could be accelerated by the use of a baking oven.

Enamel paints required the need for clean spray booths. The paint took so much longer to dry than lacquer paints; the finish was much more susceptible to damage from debris before it dried.

Lacquer and enamel paints were much more durable than the paint they replaced, but still offered minimal protection against U/V light and corrosion.

Lacquer and enamel paints are very unstable, and begin a color shift almost immediately. This fact makes them very hard to color match. People go to great lengths to match original colors. Unfortunately, the reality is the “original” color was so unstable there really is no true original color. Two cars painted the same color at the same time would not match each other after a few years time.

Today’s urethane paints offer much more protection than the lacquer and enamel paints they replaced. Urethane paint cures in three steps: evaporation of the reducer, oxidation of the resin and an irreversible chemical reaction between the resin and the isocyanate catalyst. Urethane paints began to be widely used in the late 1980s.

Base/clear paints offer even more protection. The color coat is completely buried under a protective clear coat. The clear coat provides the gloss in the paint.

Modern catalyzed urethane primers and paints offer a finish that can easily last the life of the car. I have found bare metal painted with epoxy primer and top coated with urethane paint offered very effective protection against corrosion.

So, what is an old car person to do?

Nitrocellulose Lacquer is almost impossible to find today. It also cracks easily, and will return to a liquid when exposed to solvents. Lacquer requires sanding and buffing to get a good gloss. Enamel paints are harder to paint, do not have stable color pigments, and oxidize quickly.

An authentic restoration would require the use of the original type of paint. Modern urethane paints do not have the same gloss and color hue; however, they are much more stable. Enamel paints are still available, although somewhat hard to get. Given the time and expense involved in a proper paint job, you have to consider the service life of the paint. Do you want to paint it again in 10 or 15 years?

Modern urethane paints are very forgiving to paint, and last a long time. Modern urethane finishes have a fantastic shine, and require minimal maintenance.

If you want to exactly duplicate an original car, you may want to consider a period correct paint. If you want the best shine, great corrosion protection and minimal maintenance you probably want a modern catalyzed urethane paint. I guess it is ultimately up to the user to decide which way to go.

Just to complicate things, there are new paints being used now which are replacing urethane paints. Waterborne paints are now on the market. Waterborne paints do not have the Volatile Organic Compound exposure of urethane paints. Use of waterborne paint, is being mandated slowly, due to environmental concerns.

A Drop in the Bucket List

About a year ago during a visit with our daughter, Martha in Colorado, she guided us on a trip to the Grand Canyon. On the way back she commented, “Mom we should go on another trip”. Where would you like to go? I suspect that she was thinking along the lines of a bucket list. I rather reluctantly responded the first place that came to mind “Uh, Alaska”, maybe because it starts with an A. I think I also suggested Hawaii.

Being of the digital social media generation, she immediately was on her smart phone and started the arrangements. Therefore, for a couple of weeks in June this year, we were in Alaska, landing in Fairbanks where we were met by our tour guide and bus driver, who were awesome with information about flora, fauna and wild life.

In Fairbanks we had an up close view of the oil pipeline, that runs from Prudhoe Bay to Valdez. We also had a paddle boat cruise on the Chena river where we were able to visit an authentic Athabaskan village and see a lady working her sled dogs. We took a tour bus to Denali National Park, a beautiful ride. While touring through the park, we were privileged to see plenty of moose, Dahl sheep, fox, hares and a mother grizzly bear with her two cubs.

We then took a train (first class with vista cruise type car and great dining car service) to Anchorage and then on to Seward by bus. In Seward we cruised the fjord to see sea otters, orca whales, humpback whales and a close up of a calving glacier (not an animal but a hunk of ice). The weather was beautiful and the only wildlife we didn’t see were mosquitos.

I would strongly encourage a trip to Alaska. I do think you would want to have a good guide, and would recommend Trafalgar. With twenty-two hours of daylight, seeing the sights is a given.

Our daughter is now suggesting that our next tour be Africa. That starts with A also, but I’m not so keen on that. Maybe too much wildlife.

1966 Chevrolet Corvette Stringray

This is Len & Jeanne Pallotta’s 1966 Stingray Corvette.

This is part of the Corvette story written by Len Pallotto in 2005 for Wheel Tracks….

“Our Corvette”

1966 stingray corvetteMy interest in Corvettes probably started back in 1954 when some friends and I attended the General Motors Motorama Show in Boston where the highlight of the show, for me, was the fairly new Chevrolet Corvette display. However, it would be 21 years later that I would become the owner, of one of these cars.

One day a family friend, told us that a relative of his, was going to sell his 1966 Corvette convertible and asked if we might be interested. The next thing I know, the car is in our drive, with instructions to drive it a few days. This we did and after looking the car over and considering the condition of the paint and body and how badly it seemed to handle, we sent the car back and with a definite no answer.

During the time I had the car, I had rolled the driver door window down several times, the last time, the thing failed, I ended up replacing the entire assembly inside the door. (I guess you could say this was the start of the restoration of this car, though I didn’t even own it yet.) About a week later, we were on our way to the airport in Burlington, to catch a plane to Disney World with the kids. As we turned off Williston Road, parked in the lot of the gas station on the corner, was this same Corvette with a For Sale sign on it. I don’t know what sort of chemistry took place, (I think I actually felt sorry for the car, it looked like it never had any TLC) but when we arrived at the airport, I found myself in the phone booth calling the owner and telling him we would take the Corvette.

len palotta 1966 corvette stingray
Len & Jeanne Pallotta’s son Greg is shown behind the wheel of the ‘Vette.

When we returned, the long road to this year started. My first project was to get the handling, to a point, where I could at the very least, keep the car in my lane of the road. Someone had put wide Craggar alloy wheels and tires on the car, which was a misfit. I replaced them with OEM wheels and tires with original wheel covers and spinners. Wow, what a difference! Little did I know this was to be the beginning of my continuing Corvette education.

I very soon learned that mid-year Corvettes have a parking brake system that was unique to them at the time. Although this design is used on many GM models currently, back then they were not compatible with Vermont weather and when they fail, the procedure in the service manual didn’t really help. When I finally was to the inside where the working parts resided, I couldn’t believe what I found; it was one solid mass of corrosion. Thankfully, I learned of a supplier who produced these parts in stainless steel. Great, the parking brake now works but the jubilation was short lived, as I found more problems, and all went down hill from there. As I drove the car, it seemed that every couple of weeks I would have to bleed the brakes. This led to research and learning, because of the design, using solid mounted calipers with constant contact pads to rotor, plus corrosion caused by moisture absorbed alcohol based brake fluid, pumps air into the system. This required a complete disassembly of all four calipers and master cylinder, which I did, and sent them to a vender to be sleeved with stainless steel. One more problem solved, but the list continued. Over the next few years I replaced ball joints, springs, shocks, stabilizer links, all front and rear rubber bushings, rotor and pads.

1966 chevrolet corvette stingraySince the very beginning the engine ran smoothly, but smoked moderately, however, eventually I detected a slight noise in the lower end. Before things got worse, I pulled the engine and transmission. It took a year to complete engine and transmission overhaul. A new radiator and rebuilding the wiper/washer, the carburetor, the distributor and the fuel pump was also done at this time.

During this one-year period, the inspection sticker had expired, so the day we completed the project, I made an appointment for an inspection. On the way a trooper stopped me for the expired sticker and gave me a ticket. It took a while but an assistant D.A. later dropped the charge.

1966 corvette stingray interiorOne thing that always bothered me about this car was that the electric clock never worked. So one day I took it apart and found the manufacturer’s name. To my surprise, I was able to purchase parts (at a car show). I had the face silk-screened and reinstalled it. This was great, but it made the rest of the dash look terrible. You guessed it, out came the main dash, matter of fact, out came the whole interior, seats, carpet, belts… every-thing. This was the point where we decided that we could not reinstall a new interior unless we had the body repaired and painted. Since I didn’t really have a place to do the work or the paint and my own body was now needing some restoration of it’s own, we had no choice but to have this done by an outside source. While this was being done I totally restored the seats and recovered them. In 1966 some of the options available were seat headrests and shoulder belts. These were available through Corvette restoration parts suppliers so I added these two features.

While my car was being worked on, we found the frame was very weak in some key areas, so the decision was made to remove the body and restore the frame. Again, the parts were available through suppliers.

We completed this phase of the restoration in mid May of this year (2004), as you can see, this was an on going project from day one. However, we did ,on occasion, have periods when we could drive and enjoy the car. Even when the car was off the road being worked on, we still attended Corvette shows to search for parts and network with other Corvette people to learn and exchange information. In spite of all the pitfalls, it’s been a great ride. Many thanks to my wonderful wife Jeanne, the kids Wendy and Greg, and a lot of other people, who all have either bought parts or pawed through many boxes of used parts at car shows. Thanks for just being there when I needed you for support on this project. Right now, there are left over parts still in each of our bedrooms.

Editor’s notes….

Ray Tomlinson was president in 2004 and presented the Pallotta’s with the “President’s Restoration Award” that year.

That engine that was rebuilt had the factory engine pressure gauge on the dash that was fed by a tiny plastic tube from the engine. In 1984, when Greg and his date were in high school, in formal dress on their way to an event, that tiny tube burst. The engine ceased after losing its oil. A replacement 350 Chevy engine was found and installed. The car’s proper engine is a 327 and about 12 years ago, Leonard and Greg found the engine that belonged in the Corvette. It will be going into the shop soon to make the swap.

Thank you Leonard for your story. This teaches all of us who have an old car that needs “tweaking”, to have patience….. and fun, for that short time that we are in that old car’s life. Your story is why the Vermont Automobile Enthusiasts have been around sine 1953 with a very bright future. Old vehicles keeps us all young.

 

1966 corvette stingray (back)  1966 corvette stingray (back)