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Show Paint Proper painting is an essential part of good maintenance. This obvious statement might not need amplification here, were it not for the specially harsh environment of the mountain winter and the fact that on some instruments paint serves more than a protective function. The weather instruments shelter ( Al9) and the temperature sensor shield ( Figure 6) both require white paint with suitable radiation properties. Anemometer and wind vane need to be kept painted a gloss black to minimize problems from rime. High winds, freeze- thaw cycles, abrasion from wind- driven snow and strong ultra- violet radiation at high altitudes all require special care in painting. The first step in applying a good coat of paint is to use the proper primer for the metal or wood being painted. If it is necessary to paint galvanized metal, a special primer is required, otherwise the paint will not adhere. Rusted iron or steel may be painted with a rust- inhibiting primer and paint ( Rustoleum, Derusto) if it is first scraped and wire-brushed to remove all loose scale. Follow the paint manufacturer's recommendations for priming and avoid short- cuts, which usually cause more work in the long run. Use of top quality paints is essential in the mountain environment. For the best resistance to weather on instruments and accessories, use Duco auto enamel, top- grade equipment enamel, or top- grade marine enamel. Federal agencies involved in the maintenance of high mountain instruments will need to be cautious about using paints furnished under General Services Administration contracts. Our experience with these has definitely been mixed. The small extra cost of purchasing fresh, top- grade paints from reputable manufacturers will yield many dividends in the long run. This is especially true for paint in pressurized spray cans. White paints used on radiation shields need to have a high reflectivity in the visible parts of the spectrum combined with high emissivity in the infra- red. This combination assures minimum heating above ambient air temperature. No systematic radiation studies on suitable paints have been located, so we can only recommend on the basis of practical experience. A combination of good durability and favorable radiation properties in a brushing paint is found in Fuller Equipment Enamel, Gloss White. Krylon Acrylic Paint in Gloss White is similarly acceptable for paint in a pressurized spray can. A suitable paint for anemometers and wind vanes is Flecto Varathane polyurethane enamel in Gloss Black. This paint is available in pressurized spray cans which assure an extra smooth application for maximum gloss and rime- shedding properties. These wind sensors should be repainted at the beginning of each winter season. 50 |