Rust and moisture in the shop?

[Jmercier]

Dave, I live not that far from you, and grew up in southern maine. so I have to deal with the same issues, new england weather is like that... I've got a big spray bottle and a gallon can of WD40 and i keep saturated clothes ontop of anything with a large mass (anvils, treadle hammer, etc) For the most part the things that will generate large amounts of condensation are those which will remain quite cold when the air around them warms up, power tools i just keep sprayed down with wd40 and never have a problem, the heavy things I keep covered with a cloth or rag shirt which is covered with WD40.

WD40 is great, this is the sort of stuff it was designed for.

[brucegodlesky]

I use the ceiling fan method. Fromm April to October, it runs 24/7. Really helps alleviate the problem. Not 100% but a big help. bruce

[Hillbillysmith]

If you have any outlets of power in your shop, get a dehumidifier. ALOT cheaper than a heater.

[R Funk]

Humidity in an unheated shop can be very problematic.

The problem comes from the outside air being occasionaly warmer than the contents of the shop. Warm air can contain a lot more moisture than cold air and when air contacts items colder than the air, condensation can occur.

This is the problem, warmer outside air containing more humidity, contacts the colder items in the shop and condensation occurs.

Items that reduce the condensation problems are.

1) Seal the shop to the maximum extent possible, particularly on days when the weather is warming. This will reduce amont of higher humidity warmer air in the shop and resultant condensation.

2) Do not sucumb to the tempation to open the doors wide on the warm days of spring unless you have heated the shop so the items in the shop are warm. The items in the shop may be cold enough to cause condensation. The warm air containing higher humdity coming into the shop will condense on the colder items in the shop.

3) Circulate air. Run fans to circulate the air in the shop. This will tend to keep the items in the shop at a temperature closer to the air temperature, reducing condensation due to cold items.

4) Keeping the shop heated. However my budget does not permit this.

I had a problem in one of my previous shops. The mositure was coming from the gravel floor. Do you have a concrete floor in your shop? If you do, did you put a poly vapor barrier underneath the floor? This can be a significant source of humdity. But you can can place a poly vapor barrier under the gravel or dirt to reduce this source of humidity.

I am not confident that a standard dehumidier will work in a shop in the fall, winter or spring. Most standard dehumidifiers require a 60-65 deg F operating temperature to avoid freezing up. I had a dehumidifier freeze up in my basement in the spring when the basement air temperature was approximately 65 deg F.

Dessicants such a charcoal, calcium chloride generally will not work in open enviroment such as a shop as the ambient moisture quickly overwhelms the capacity of dessicants. They will work in relatively tight cabinets and drawers.

Light bulbs or other low powered heaters reduce condensation as they heat the items reduces the potential for condensation. Be careful as they can cause fires.

[Dave M]

Well I have been running 2 fans in the shop in combination with a small electric heater for 2 days now and it seems to be working fine. When I poured the slab I put down a vapor barier but I did not put down under slab insullation I wish I had because the floor is sweating because the slab is so cold and the air is so warm. Oh well build and learn. On real damp days or days with big temp change I will use a portable kerosne heater that I have, until I can get the wood stove installed.