Originally Posted by
SCzEngrgGroup
First thing you need to understand is why things tend to rust in the winter. Once you understand that, you can come up with a strategy that makes sense for your conditions and habits.
Cold temperature, by itself, will not significantly harm your machines or tooling. Your enemy is condensation, which will occur whenever the temperature of the equipment and tools drops below the dew point of the air in your shop. If you take a warm shop, close the doors, and lower the temperature, you will never get condensation, because the dew point will always be up somewhere below (but near) the original warm temperature. As long as the temperature of the machines remains above the temperature of the air outside, you will get no condensation. Where some care is required, is when the machines are colder than the outside air. Say you closed up your shop in the evening, when the temperature was 50F. Overnight, the temperature dips down to 30F, then, in the early morning, rises back up to 40F. The machines, which have a large thermal mass, will still be down near 30F. If you then open the doors, you let in a lot of 40F air. As soon as that air hits the 30F metal on the machine, moisture will condense out on the machine, and rust will result. To avoid this, follow a few simple rules:
1) Keep the doors closed as much as possible. Use only a small door to go in or out, and go in or out as quickly as possible, to admit as little outside air as possible.
2) If you MUST leave a door open, or open a large door, avoid doing so early in the day after a cold night, when the outside temperature is significantly warmer than the overnight temperature. If necessary, heat the shop for SEVERAL HOURS to get the machines warmed up before opening a large door. It is the temperature of the machines that matters, NOT the temperature of the air.
3) Combustion heaters of any kind create HUGE amounts of water vapor, so NEVER use ANY kind of combustion heater unless the combustion chamber is completely sealed, and the exhaust is vented to outside. This means no wood-fired heaters, no kerosene space heaters, no gas heaters - basically no heater with ANY kind of flame, unless it has a flue that vents outside the building. Electric heaters are very good, as they create no water vapor.'
My practice is to leave the shop unheated when not in use. I have three 1500W electric space heaters ($20 each from Sears). Avoid "radiant", which will heat you but not the machines. An hour before I need to start work, I go out and turn on all three heaters. By the time I get out there, the shop is warm, and I can turn two of the heaters off, and the third one down enough that it only runs part of the time, even on the coldest days (in the 30s here). The cost of this is next to nothing, the shop is comfortable, and, in over 10 years, I've never once had a problem with rust. If it's REALLY cold outside, you might want to leave on a heater with a thermostat, just to limit the lowest temperature at some reasonable value (maybe 40-50F), but I've never found that necessary where I live.
Regards,
Ray L.