Professionals and Amateurs Together

Workshop Temperature


I have a garage workshop which is insulated and heated with an electric ceiling mounted unit. I am wondering what issues I may have with tools and stored wood by dropping the temperature down to the low 50s or even as low 45 when I plan on being out of the shop for a couple of days and then heating it back up to a comfy 65 for weekend work?—Cam Morin


Garrett Hack replies: I doubt you will have any issues with your tools. It’s the summer humidity and swings in temperature that usually causes rust. Stored wood won’t care either. But when you go to build a piece of furniture, your wood will not be acclimated to the same conditions as a house (constantly heated) and might be less well behaved.

Jon Siegel replies: As I am writing this in February 2022, prices for fuel have risen sharply. I realize it’s hard to justify continuously heating a woodshop in a garage or outbuilding if you’re only using it on weekends. However, there are many problems associated with a woodshop that undergoes large temperature changes.

  • Rust on tools. Condensation will form on tools any time the temperature of the metal is below the dew point.
  • Lumber will not be (or stay) fully dry if stored in an unheated building.
  • Completed projects will suffer from wood movement when taken from your shop into the home.
  • Glue has to be warm to cure correctly. Check the instructions as the minimum temperature will vary with each type of glue.
  • Finishing materials should be applied to wood that is warm all the way through.
  • It is not sufficient to heat up the shop just before applying the finish because air inside the wood will continue to expand for a long time as the wood warms up.

Dan Wallace replies: I have a Modine Hot Dawg propane heater with a sealed combustion chamber (doesn’t add moisture) so it works like an electric heater. I have done what you want to do for the last ten years and I’ve even gone as far as dropping the thermostat down to just above freezing until I realized it actually cost me more to bring my shop up to temp. Now I set it at 50° when I’m done. My thinking is that the shop drops temperature slowly and when heating it rises fairly slowly. I find that my cast iron tools take quite a bit of time to warm up so there is no chance of condensation collecting. I think the materials and machines aren’t hit with an abrupt temperature change that would neither add nor remove moisture too quickly.

Bob Couch replies: I also have a well insulated garage workshop and use a 220v ceiling heater. It is hard to answer your question to some degree. All of my tools and machines live in my garage space, however all of my finishes are stored in an adjacent utility room that’s also heated. If your finishes and adhesives are not stored in a warm place, I would just leave the temp no lower than 55°. This also helps with humidity/moisture content. It’s part of the cost of your hobby and pleasure.

Tags: Rust, Shop