When it is time to polish your bare aluminum airplane, you obviously need a clean, dry hangar in which to do the polishing. However, there are a few weather topics that need to be considered.
First is temperature. Most aluminum polishing products recommend using them when you have warm, but not hot temperatures. Generally, a temperature of 70 degrees to about 85 degrees is ideal. While you can polish at cooler temperatures, the end result probably won’t be as good and the effort to get there will take longer. The best polishing effectiveness occurs when the buffing pad is generating heat. Cold ambient temperatures simply make it more difficult to generate the necessary heat.
Naturally, living in a warm climate is the best situation for the owner of a bare aluminum airplane. If you live in an area of the country that has cool or cold winter temperatures, your choices are limited to only polishing when the weather is warm or finding a way to heat your hangar.
The next item to consider is humidity. Just as warm temperatures help with the polishing process, so does low humidity. If you do polish during periods of high humidity, you are likely to see a final result that is cloudy in appearance.
I don’t have a specific number for an appropriate humidity level, but if it is raining outside your hangar on the day you want to polish, it is probably best to do something else.
Although technically not a weather issue, you should avoid polishing your airplane outdoors on beautiful sunny days. While the light will be much better than the best indoor lighting arrangement, the sunlight will quickly heat the polished surface to a temperature that is unacceptable for polishing, even if the ambient temperature is somewhat cool.