New Clear — Part III: Buffing and Polishing
Scratch-Resistant Clear Coat
By Kevin Farrell
In Part I of this series of articles (Auto Laundry News, February 2010), we tried to demystify the newer scratch-resistant clear-coat technology. In the March 2010 issue, we discussed in Part II the challenges detailers face when attempting to wet sand this new clear coat. In this month’s issue and the next, we will discuss how to buff this type of clear and what different methods and products may have to be used in the process.
Let’s go back, for a moment, to the days when the only type of paint system used on automobiles was single stage. Cars were painted in either a lacquer or enamel finish. These finishes differed from today’s clear coat systems in that the pigmented paint of yesteryear was exposed to the elements and direct UV rays of the sun. Therefore, these paint systems would fade and oxidize and had to be buffed rather heavily to bring back the original
These paint systems differed slightly from each other, but both basically produced fairly hard surfaces that required a detailer (or whatever they were called back then) to employ an aggressive buffing procedure. Many guys used very aggressive wool pads, compounds that felt like beach sand, and very high speeds on a rotary buffer. Aggression was the norm, not the exception.
Even when paint systems changed over to basecoat/clear coat in the early 80s, the first generation of clear coat was very hard and required buffing methods similar to those employed on a single-stage system. If a detailer did not know the difference between these paint systems, or was not aware that they were different, he generally would not make a critical mistake in buffing an early generation clear coat.
BUFFING METHODS HAD TO CHANGE
When clear-coat systems began to get softer in the late 80s and through the 90s, these aggressive methods of buffing had to be changed. No longer could a detailer use a “beach sand” compound and a very aggressive wool pad along with 2500 to 3000 RPM on a rotary buffer. This strategy would cause too much damage to these clear coats such as burning, blistering, hazing, and swirling. This era introduced more prominent use of orbital buffers, foam pads to correct a softer clear-coated finish, special products that were “safe for clear coat,” and much lower speeds or even discontinued use of a rotary buffer. Detailers became afraid of the rotary buffer and began to rely on less aggressive methods of paint correction because of the fear of the problems previously mentioned.
And Change Again
For the most part, these less aggressive methods worked if a detailer did not want to use a rotary buffer. An orbital could be made to do the job, although it would take longer and still not
produce the finish of a correctly used rotary buffer. However,
with the change now being made by more and more car manufacturers to scratch-resistant clear coat, more aggressive methods need to be taken to correct these finishes.
Today, there are products available that are labeled as scratch-resistant compounds and polishes. They are made more aggressive in terms of the type of abrasives used, the hardness of the abrasive, its shape, and the percentage of overall abrasives in the product. But there is more to the entire process than just buying a product. We have to know what’s going on with these scratch-resistant clear coats as we buff them to get a better understanding of how to properly and quickly correct the finish.
No More Instant Gratification
There are too many detailers, as well as body shop guys, who demand instant gratification when they buff. They want to go back and forth once or twice and see all the scratches and imperfections just disappear. This obviously would save time but you have to be aware that the more aggression you use the greater the risk of hazing, swirling, and burning. Remember, clear coat of any kind is a form of plastic. If it’s heated too much, it will get very soft and then burn.
With softer clears and older generation clears, it was easy to have a product and pad combination that would cut pretty fast and leave limited swirls and hazing. We could have almost instant gratification. This is why those aggressive products and buffing methods had to be backed down for use on the softer clear coats and many guys went to orbital buffers almost exclusively. With a scratch-resistant clear, we have to buff it a little bit differently, but we first need to understand what’s going on with these clear coats as we buff them.
We’ll conclude this series of articles next month with a brief recap of scratch-resistant clear coat chemistry and a look at the tools and products you may have to use in the buffing process.
Kevin Farrell owns and operates Kleen Car (www.kleencarauto.com), a full-service auto-detailing business located in New Milford, NJ. Kevin is also an instructor for a detailing program he developed for, and in conjunction with, BMW of North America. His background includes auto dealership experience and training through DuPont, General Motors, and I-Car.