A Layman's Guide to Restoration Part 6
by David Grainger
President, The Guild of Automotive Restorers
Painting cars has become a very high tech and difficult thing to do, especially compared to the old days when a can of lacquer, a compressor and a spray gun was all you needed.
As the technologies surrounding paint have changed, and as the materials in it have advanced, the results for the old car hobbyist have not always been the best. Modern paints are tailored to be sprayed by robots and to have very fast dry times under certain heats and humidities. Now I won't go into the technical details which are complex and quite bluntly as dull as ditch water, but I will tell you that as far as I am concerned many of the problems associated with modern paints are that because of the formulations and the resulting orange peel, they are very hard to smooth and require a lot of post paint attention. They do have a lot of shine and this is often the result of the clear coats which have been applied, but if you look at a reflection in them it will be fuzzy and distorted, rather than crisp and mirror-like which is the case with well laid lacquer. If you doubt this look at almost any new modern car. It is amazing what we accept simply because it is factory standard. I sometimes wish I could get away with some of the crummy paint jobs and poor fit and finish that the manufacturers do, but that is certainly not in the cards during a good restoration.
So how do you remedy poor paint lay up problems? Well the truth is you can't, aside from in your initial choices as far as the materials that the paint shop uses.
Based on my experience, some of the paint companies are struggling a bit, or perhaps don't care because, let's face it, the finish on your 54 Chev or 34 Studebaker doesn't matter to them as it is a very small part of their business.
When you lay many of the modern urethane paints the orange peel is unavoidable and is found not only in the base but in the clear coats as well. Laying on more and thicker, which was the solution with older paints which allowed them to flow and eliminate peel and dryness in the finish, actually encourages many of the modern formulations to peel and wrinkle even more aggressively.
In my shop what we have had to do to eliminate the problem is to stop in between each stage and sand the finish. This means that the primer is first sanded to remove any and all irregularities, and yes, primer can have orange peel in it, which transfers up through the ensuing coats. After the primer is sanded to a flawless texture the base coats are applied. Now in this description I am talking about base clear systems. Some paints are single stage and the peel can be sanded and buffed out after the painting is complete. With the base clear paints if you don't stop and sand the base after you lay it down you will have a fuzzy light return no matter how much you sand out the clear coat.
Sanding is done with a soft block and fifteen hundred or two thousand grit sandpaper. When sanding the base the sander must be careful not to break through the base to the primer below. The same care must be taken after the clear coats are applied and during their sanding to avoid breaking through clear to the base which will cause a very visible blemish and require a trip back into the spray booth.
Now I am not advocating that you do these procedures yourself as they do take a fair amount of skill and experience, but if you know about them and understand them then when you get your car painted you will be able to talk to the paint shop and determine if they know what they are doing and they will be able understand what it is that you want and expect. There is no doubt that this amount of attention and sanding is more expensive but the end results will make your car not only more attractive but also the finish will more closely resemble the original.
Now to the paint companies themselves. Paint companies tend to cycle so the brand of paint which was top dog maybe ten years ago may not in fact be as good today.
When I first started I used paints from P.P.G and they were superb. As time passed they changed and the results that we were getting were not what we needed so we changed. That change was to Sikkens, another top name and the paint quality was very good but over the last few years, changes to formulations have caused problems and the finishes have not been what we what we wanted. So the search begins for a better, more efficient paint to achieve the results that we demand with less work.
Recently the problem was solved by using a different clear coat but having just returned from a trip to California I have seen the results of a new paint system, which really impressed me.
This was a water based system and paint which has not yet reached Canada except in experimental cases but which I have been trying to get for quite some time. These new water based paints will be the new systems that will replace urethane, which is full of very nasty ingredients. This is not to say that the water based paints are completely friendly, I am sure they are not, but they will inevitably replace current paint systems as legislation forces manufacturers to produce less toxic chemical formulations.
The paint that So Cal (Southern California Speed Shops, a recent ally and associates of The Guild) uses on their high buck hot rod projects as well as their restorations on old rods is a Dupont water based paint, which seemed to yield fantastic results. The car we saw had not even been cut and buffed in, yet the paint had a gloss and luster that was superb. Hopefully this technology will soon be released in Canada. I would imagine the reason that it hasn't is simply because it hasn't been legislated and the paint companies are probably loathe to change over from urethane and its huge investment in research and marketing. The reason that water based is used in California is because it was made illegal to shoot other non-water based paints, at least in the greater Los Angeles area.
With care and attention to detail urethane paint can be made to resemble very closely lacquer and other old paint systems, but as formulations have changed and various constituents within the paints have been legislated out, the urethane paints have become more difficult for the painter to achieve glasslike with. When you are restoring your car, keep this in mind and plan for it, discussing possible problems with the painter and making sure he knows exactly the results you want when your car is complete. The amount of attention required after the paint comes out of the booth is almost equal to the attention devoted to the prep before it went in.
That will cost you extra money so keep that in mind.