Paint Basics
What: At one time everyone has painted something. Around the home it usually is done with a brush or roller. Some larger jobs are done with a spray gun. Small jobs can be done with spray cans. None of these experiences prepare us for the complex job of painting a car. This task is best left to a professional.
How: In the “old days” lacquer based paint was the primary type of paint used in the painting of cars. It was easy to apply and could be rubbed out to create a deep mirror-like finish. Dirt and imperfections could be sanded out and sprayed to blend in. This made the process very forgiving limiting the need for controlled environments like high tech paint booths and spray equipment.
Enamel based paints were much more difficult to apply because they tended to run and were very difficult to spot areas that had imperfections. Usually the entire panel had to be stripped and repainted to repair any imperfections. Enamels were more durable than the lacquer based paints, especially when the finish was baked after application. They were not as smooth as the lacquers, having a surface similar to the surface of an orange peel.
Environmental concerns and the need for more durable paints led to the development of multi-application coatings like base-coat / clear-coat and acrylic based paints. Concerns for the release of toxic solvents into the atmosphere spawned laws that limited these emissions. To comply with these laws spray guns that used HVLP (high-volume low-pressure) were developed. Driving the paint through these spray guns requires air compressors with much higher CFM (cubic feet per minute), about 13 CFM at the gun. They require the use of high flow quick-connects and at least a 5/16” I.D. hose.
Another reason for leaving the job to the professionals is that most of the clear-coats used today are designed for paint booths using the flow of air across the surface to cure the paint. Without air flow the solvents can be trapped into the undercoats causing all kinds of problems like blistering or smothering the paint causing it to lose gloss and killing the durability of the paint job. Air movement helps cure the paint and keeps the fumes away from the painter.
They are also much more threatening to the health of the painter. Breathing in the fumes or absorption from contact with the skin can be life threatening. Respirators and protective clothing is required when spraying these exotic finishes. So applying the current exotic finishes used on today’s hot rods and customs is best left to the professionals.
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