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Hi all,

I'm sure this has been discussed before, but I'm a new builder and currently evaluating whether its truly possible for me to work in my existing shop. I live in the SF Bay Area where the climate is fairly moderate, but after 2-3 weeks of monitoring humidity in my shop/garage, I am seeing fluctuations from 30% to as much as 60-65% relative humidity. Typically the humidity ranges in the 35-50% and drops as the day/room warms up.

Can I build guitars and store materials in this environment? I'm fine with avoiding higher humidity days for critical glue-ups, but controlling the environment is going to be very difficult for me. My only other option will be to move the operation into the house.

Any thoughts? Thanks.

/mark

Hey Mark

I'm in Fresno. I work outside and store my materials in a second closet in my room. That's also where I keep my dehumidifier. According to my calibrated hygrometer, the humidity fluctuates between 46-55. I use a Soleus 25 pint dehumidifier. It would be better to keep it between 40-50, but the Soleus is dead quiet (it's 10 feet away and I can't hear it) while the LG I had for three weeks before returning it to Home Depot was just about as loud as a washing machine. Important compromise, given that it's in my bedroom.

Rick Turner's mentioned another trick. Keep your humidity sensitive materials in a sealed garbage bag with an acoustic guitar dehumidifier.

Links to what I use:

Caliber III hygrometer: http://www.amazon.com/Western-Humidor-Caliber-Thermometer-Hygrometer/dp/B0007W1EA6/ref=pd_sim_k_title_5

Hygrometer calibration: http://www.amazon.com/One-Step-Hygrometer-Calibrating-Kit/dp/B000A3UBLA/ref=pd_sim_k_title_3

Dehumidifier: http://www.amazon.com/Soleus-CFM-25E-25-Pint-Dehumidifier-Humidistat/dp/B0002PCT0C/ref=sr_1_2?ie=UTF8&s=home-garden&qid=1205206755&sr=1-2

Swings in Rh are the issue. if you are in a constant 20% and it never changes then all would be fine as long as the guitar never left that environment. But none of use live in such an environment. I live in one of the most stable environments in the country. It is on the low side compared to most of you at an average 35% most of the year. I have to add humidity most of the time to be at 40-50%.

If you do as Rick says and store your raw wood and worked wood in a controlled area when not in work and pick your working times based on Rh levels at the time you can live with out controlling your shop. I did just this for four years. But it really can slow you down if you live in an area with constant swings.

So you have to decide how you want to work. Do you want the Rh to control when you work or do you want to control the Rh. If you’re building for your self only then living with a 5-10% swing is workable. Much more than that and you find you have problems.

I'm not convinced you need to keep your raw materials in strictly regulated temp and humidity condtitions; I know I certainly don't, and folks that air dry wood certainly don't. I don't have tight control over my humidity, but it's almost always (indoors) between 40 and 60, usually between 44 and 60, so I'm happy enough. I pay attention when I glue things, I move the raw, roughly dimensioned stuff into the controlled area about a month or two (at least) before turning it into anything instrument-shaped, longer if reasonable, but reasonable amount of my stock is in a shop that's got no climate control, humidity swinging around, temperature swinging around, and some of it's outside. Out of the rain, but outside.

All the dimensioned, thinner stock is in the 'dry' area, because it's thin and likes moving around too much otherwise.