Importance of climate control

**Cragger** · Dec-08-2006, 1:34pm

How important is it to keep the climate it in your shop constant? I am just getting into wood working and am about to start on my first instrument as well. My shed is 10'X12' and has no insulation. I live in Birmingham, AL so the humidity can be anywhere across the board and so can the temperatures. For just a small time wood worker and beginning builder, should I be concerned about the changing conditions? What can I do to help control the conditions better or be able to work with what I am given?

**sunburst** · Dec-08-2006, 1:45pm

It's important, and yes, you need to do what you can to control humidity.
Wood doesn't really care how warm or cold it is, but the temperature has a direct affect on relative humidity, and relative humidity has everything to do with the moisture content of your wood.

I'd suggest reading the chapter in Understanding Wood by R. Bruce Hoadly intitled "Water and Wood" and the following chapter; "Coping with Wood Movement", and you'll know all you need to know about the subject.

**Cragger** · Dec-08-2006, 2:04pm

Thanks for the info. I will definately take a look at the book. I checked the Library and they have it. I should be picking it up in the next few days.

**carleshicks** · Dec-09-2006, 11:12am

what type of humidity control was used by Gibson and othe instrument manufactures 80 years ago. I have always wonderd about this.

**sunburst** · Dec-09-2006, 11:31am

It is often asked (paraphrasing here); "OK smart***, if humidity is so important, how come there are so many Stradivarious violins still around? Stradivari didn't have no stinkin' humidifiers and dehumidifiers!?"

Well, Strad's method of controling humidity was living in southern Italy. The climate is quite a bit different than Birmingham.
So anyway, Gibson probably didn't do a whole lot to control humidity back in Kalamazoo, but you can bet they are doing something about it in Nashville!
My assumption is that they would have needed more attention to the humidity in the winter in Kalamazoo. The summers aren't as brutally humid as they are in the southeast US. They might have used steam heat, and/or could have boiled water for humidity. There are plenty of "cave man" type ways to add moisture to the air.
You can get away with building insruments in conditions that are less than ideal, especially in areas of the world where the fluctuations aren't extreem, but considering that the technology exists to control the humidity fairly inexpensively these days, it only makes sense to keep it under control, especially in places like Birmingham and Nashville.

**carleshicks** · Dec-09-2006, 11:58am

it is funny that you mention the climate in Kalamazoo because I live about 18 miles from the old Gibson Plant. And there is no humidity in the winter and sometimes 95% humidity in the summer that is why I was curious if anyone had an Idea what method Gibson used.

**sunburst** · Dec-09-2006, 1:55pm

I've never been to Kalamazoo, and I'm a little surprised it get's that humid 'up there' very often. Anyone who lives in the southeast US in the summer knows the kind of wilting humidity that shows up around here sometimes. I've had everything I own grow a layer of mildew, all my envelopes seal themselves, that sort of thing. That's no time to be glueing up instruments without climate control, to say nothing about trying to spray lacquer!

**Antlurz** · Dec-09-2006, 3:07pm

A normal misconception, John. The midwest can be extremely brutal, humidity wise. All those lakes, marshes, etc. really do the hyper evaporation bit through the summer.

Even a bit farther south, like here in Iowa, when the sun beats down on billions and billions of big corn stalk leaves, the evaporation can be very opressive. A few years ago, we vacationed in New Bern, N.C. with an old school chum. He went on about the opressive humidity down there, and wanted to know how we were holding up because of it. In fact, it was a pleasant detour from the dripping wet humidity up here in Iowa.

It's not unusual at all to go from 80 or 90%, down to 20% from one day to the next.

Ron

**Dave Cohen** · Dec-09-2006, 5:37pm

All but the most arid locales can occasionally get up to 100% RH every once in a while. When it rains, the Rh is very close to 100%, though your shop may not get that humid if it is tight. In Richmond, VA, the outdoor RH swings are much more extreme than inside my shop. The shop has a Tyvek barrier and what is now standard insulation, both of which slow down the exchange of moisture.

The Midwest is considered a "continental" climate zone. On my visits to Chicago and DeKalb, I found that the RH can vary greatly in the Summer. At times, it was as humid as August in the Mid-Atlantic, while at other times, a drier air mass came in from the Canadian shield. Same deal down in St Louis, where my sister & brother-in-law used to live.

**Cragger** · Dec-11-2006, 7:55am

So, what would be an inexpensive way to control the humidity in my shed? It is basically just four walls with standard framing techiniques and a low pitch roof. There is no insulation, flooring, or ceiling.

**sunburst** · Dec-11-2006, 9:59am

That's not easy. You'll have to spend some $$ to have any real control. Sealing the space as much as possible is your best bet, and running a humidifier and dehumidifier.
Actually, my shop with R-19 walls R-38 ceiling, tyvec wrap, and concrete floor is pretty easy to control in the summer with just air conditioning. I don't remember it getting above about 60% RH last summer. I'm having more trouble keeping the humidity up now. I need a big ol' humidifier.

Tyvec, BTW, is not a moisture barrier. It just slows down the movement of air and moisture.

**Mario Proulx** · Dec-11-2006, 10:42am

What John said; you need to insulate and use a vapor barrier if you want any chance at controlling the RH.

Once you have it sealed up tight, and the RH is where you need it, one way to help the humidifier and dehumidifier do their jobs is to have a lot of raw wood in the shop. The raw wood will take in moisture when the shop gets a little wetter, and release it when it goes a little dry. Think of it as a flywheel that can store energy.....

If this is just a hobby or a one-time deal(ha! There can never be "just one" mandolin...), yo can squeeze by with simply insulating and wrapping a smaller room of your "shop", and storing all your woods and doing all the assembly within that room.

**Paul Hostetter** · Dec-11-2006, 11:54am

Originally Posted by

Well, Strad's method of controling humidity was living in southern Italy.

Sorry, but when he wasn't fleeing plagues, he lived his working life in Cremona, which was very much in Lombardia (what is now northern Italy), where the climate is very much like Kalamazoo, a place (having grown up in Detroit and a frequent visitor to Parsons Street in my misspent youth) I am also personally quite familiar with. The description of its humidity ranges - "no humidity in the winter and sometimes 95% humidity in the summer" is spot on for both places. Strad had an upstairs drying room with open windows to catch the summer breeze.

I know Gibson didn't do much about humidity control, but as you can see here, they did have windows that opened in the hot, muggy summers. I remember the offices where Bellson and those guys hung out having air conditioning, but the plant itself was wide open in summer.

**Darryl Wolfe** · Dec-11-2006, 2:48pm

How important? #Here's how important. #In SC we rarely need much of humidification. #However, inside the house I do humidify the room I keep my instruments in. #On occasion I will leave an instrument in the shop which has no humidification (and rarely needs it). #So here starts the new nightmare. #I left a guitar out in the shop for several days (last thurs Frid Sat). #The humidity got quite low for SC during this period and frankly I forgot about the guitar. #The shop is a two-car garage and occasionally the door goes up. #Door goes up for 15 seconds and back down, 70 degrees F inside, 28 Degrees F outside. #Center seam of guitar top goes POW!! about 10 seconds after door finishes closing. #It sounded like a string breaking or a bridge pin popping. Is humidification and climate control important. #Yep.