Hints and Kinks, QST January 1980
I read with interest Doug DeMaw's explanation in September 1979 QST about using a drying oven in paint finishing of radio projects. I thought some readers might be interested in my method of getting a rather nice wrinkle finish on a panel.
A bare panel can be primed with standard zinc-chromate spray primer. Allow to dry naturally. What I do next is to wait until my wife has gone for the day so that I can heat the panel for about 20 minutes in the oven at a 300º F temperature. After I'm sure the panel is completely heat-soaked, I remove it from the oven, place it on a piece of wood and spray it with the finish paint. The finish coat dries instantly. But rather than setting flatly. it provides an attractive wrinkle. Anyone trying this method should not let the paint get too close to the project, lest runs appear.
Two other tips -- aluminum should always be primed before painting. Zinc-chromate is the better choice for this purpose. For finish paint I prefer the type used on machinery. It is known as "machine gray." Most industrial supply houses carry it in spray cans. The price is about the same as one would pay at ordinary outlets, but the paint seems to be tougher. It is available in several tones and brands. I find that I can match S-Line colors fairly well and the finished work takes transfer letters nicely. -- R. C. Locher, Jr., W9KNI, Deerfield, IL