Closing the Box and Humidity

[Eric Knapp]

Hello, I'm getting close to being able to close the box with my old archtop salvage build. I've been putting it off due to the humidity I'm facing. My shop is in my detached garage with no AC. I'm planning on closing it in with new walls for the winter and then I'll be able to add heat and a window AC unit for next summer. But, the humidity is really high here in Wisconsin. It's 88% here right now and maybe higher in my shop. Am I correct to assume I should not glue up the box at this point? It's an old archtop so the wood has been around for a long time. I'm still reluctant and would love some advice. I'm not in a major hurry and I want to do this right.

Thanks,

-Eric

[Brian Evans]

I would probably wait till fall. I only start gluing in late September, when humidity levels average out around 50%. Humidity varies greatly with air temperature. This morning it was 70 degrees and around 85% humidity, right now it's 82 degrees and 69% humidity.

[Eric Knapp]

I would probably wait till fall. I only start gluing in late September, when humidity levels average out around 50%. Humidity varies greatly with air temperature. This morning it was 70 degrees and around 85% humidity, right now it's 82 degrees and 69% humidity.

Thanks, Brian. My shop will always be too humid until I can get some climate control in there. I also have to seal up the windows and doors so rain stops flowing in. Once I have the new walls in place it will be about 350 sq. ft. (32.5 sq meters). My pro shop was 1,000 sq. ft. (93 sq. meters) so I need to get used to it. It's not efficient space yet. AC, heat, and dehumidifiers and then I can glue the box.

-Eric

[Barry Daniels]

You can keep the project inside your house (if it is drier) and then take it to your shop while you are working on it. Or you can make a drying cabinet which is basically a box with an incandescent light bulb in it. Neither is as useful as a sealed and dry shop but they can give you a measure of humidity control until you fix the shop.

[Eric Knapp]

You can keep the project inside your house (if it is drier) and then take it to your shop while you are working on it. Or you can make a drying cabinet which is basically a box with an incandescent light bulb in it. Neither is as useful as a sealed and dry shop but they can give you a measure of humidity control until you fix the shop.

Thank you, good ideas. My house is not much drier. I live with 3 wonderful women who don't like AC as much as I do. I was thinking I should make a drying box at some point but the real answer is I need to get my shop closed. I'm working on it and planning the budget to pay for it. I'm doing most of the work myself to keep costs down.

-Eric

[Karl Wicklund]

I'm anticipating he same fight here. At our new home the shop space is about three times larger, but not tight and not insulated - going to be a struggle. What's your construction like? Mine's a pole shed.

[Bryan Bear]

I hope you can get used to downsizing to a shop that is twice the size of mine

For whatever reason, my basement shop has been surprisingly dry and stable as far as RH goes. I don't have room for a drying cabinet but since my shop is so small, I sometimes run a space heater in there if the humidity is a little higher than I like when I want to brace or close the box. Raising the temperature in the room lowers the RH and it doesn't take a ton of time for thin plates to equilibrate. It also helps a little bit with open time for HHG. I know your shop is bigger and this may not work well but if you have a space heater laying around, you may want to try a few experiments. For me it is as easy as placing the small space heater on my bench top (not blowing directly on my work!) and letting the room warm up before I am ready to do the bracing. Then by the time I have everything ready to go and the glue warmed up, the project seems to be equilibrated well enough. Keep in mind, I'm not really having to drop the RH a whole lot, just food for thought.

[Eric Knapp]

I'm anticipating he same fight here. At our new home the shop space is about three times larger, but not tight and not insulated - going to be a struggle. What's your construction like? Mine's a pole shed.

My shop is in a detached garage with two garage doors. The walls and ceiling are insulated well but the doors can't be sealed. I am going to add an interior wall that will isolate my shop area from one normal garage stall. We keep one car in the garage and the rest have to suffer through the snow. When the interior wall is done I believe I can have a climate controlled room. During the wet summer months I'll be running AC and a dehumidifier. At 350 sq. ft. I'm hoping it won't cost too much. It will be small but will have lots of wall space. That will have to do and will keep me from being tempted by big machinery.

-Eric

[Karl Wicklund]

I got my first taste of this craft at the elbow of a self-taught older friend. His humidity control in the winter was a pan of water on the wood stove. In the summer, he didn't build. His work was unorthodox in many ways, but he turned out beautiful guitars that have held up well over the past 25+ years. I guess we'll figure out ways to make it work.

[Eric Knapp]

I got my first taste of this craft at the elbow of a self-taught older friend. His humidity control in the winter was a pan of water on the wood stove. In the summer, he didn't build. His work was unorthodox in many ways, but he turned out beautiful guitars that have held up well over the past 25+ years. I guess we'll figure out ways to make it work.

Ah! I just noticed you are in WI. Do you ever make it down to Madison? That's where i am.

-Eric

[Karl Wicklund]

We make it down that way every so often, maybe a couple times a year. We are up in the NW, about 90 minutes south of Superior, 90 minutes NE of the Twin Cities. Near a town called Luck.

[Jake Horner]

Hiya Hiya,

I'm facing the same problem, and I'm wondering how things are working out in your shop(s). My shop is in a Pennsylvania basement with sandstone walls. It gets VERY humid in there during the summer---walk in and immediately start sweating humid. There is a window so an AC unit next summer is a possibility. This basement is pretty large, about 1000 sq. ft. I would guess, broken up into several rooms. I can't isolate my work space so I'm going to have to deal with the whole space I think.

[Brian Evans]

I have a 500 square foot room in my basement that I dehumidify with a decent quality dehumidifier, and it keeps humidity to around 50% pretty easily. I just store stuff in the room, including wood, it's not a workshop. Much cheaper than air conditioning for a basement that is probably already cool. As you know, cool air holds much more humidity that warm air.

[Jake Horner]

HA! I didn't know that cool air holds more humidity than warm air. I thought it was the opposite.

It's not terribly cool in the summer. But I'm going to try a dehumidifier first, before the AC.

I thought it was important to get the relative humidity down to around 10% for instrument making.

[Barry Daniels]

NOT 10% !!!!! That is wayyyy to dry.

I have my shop at 45% year round.

[Bryan Bear]

HA! I didn't know that cool air holds more humidity than warm air. I thought it was the opposite.

Warm air can hold more moisture than cool air. For a given amount of water vapor in the air, cool air will be higher RELATIVE humidity since it can't hold as much (is closer to being saturated). That is to say that if the air had X amount of water vapor and the temperature dropped the RH would go up even thought there is not more water vapor.