The Science of the Guitarmidor™

Protect your investment with Guitarmidor TM...

Environmentally controlled, heirloom quality furniture.

Moisture and Your Instrument• Too little moisture damages the wood of the guitar neck and

body- from cracks and pulls to “spider” defects in the finish. • Too much moisture can cause warping that damages the

fretboard, bridge, body and neck, ultimately making the guitar unplayable.

• Moisture affects guitars (both acoustic and electric) in similar ways, and with prices for such instruments rising daily, it pays to be conscious of moisture.

• Moisture is frequently referenced as Relative Humidity (RH). Relative humidity is the amount of moisture in the air compared to what the air can "hold" at that temperature. When the air can't "hold" all the moisture, then it condenses as dew.

RH and Wood Dimensions• Wood constantly exchanges moisture with its

environment. This exchange can stress the wood and finish over time.

• A 40% change in RH can create a:– 1% change in the longitudinal dimension– 4% change in the transverse dimension– 10% change in thickness

• Taylor Guitar has shown that the face of a guitar will change by as much as 1/8” for RH changes as small as 17%.

Experiments carried out by physicist Jurgen Lehmann and published in The Strad Magazine (September 2003)

RH and Resonance Frequency

• Higher RH equates to lower resonance frequency and weaker harmonics

• Changes in RH create dramatic variations in perceived instrument sound.Experiments carried out by physicist Jurgen Lehmann and published in The Strad Magazine (September 2003)

RH and Location

• Temperate – 20% changes in RH on a daily basis

• Hot and Dry – Very low RH

• Hot and Humid – Wide fluctuations in RH throughout the day

• Cool - Consistent but relatively high RH

• Where does your instrument live???

Daily RH Δ across the US

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100

Newark NJ Las Vegas,NV

Tallahassee,FL

Anchorage,AK

MorningAfternoon

Daily US RH Averages (look up your city)

Temperature Effects

• Variations in temperature can induce cracks in the finish since wood and varnish expand and contract at different rates.

• Excess heat can damage or destroy the bonding joints in a guitar.

• Changes in temperature and RH are related… RH will always change when the temperature does.

• Outside air at 20° F and 60% RH will decrease to 5% RH when heated to 70° F inside your home.

RH vs. Temperature

Change in RH for a fixed moisture content

0

20

40

60

80

100

40 50 60 70 80 90

Temperature

Rel

ativ

e H

umid

ity

RH Curve

Guitarmidor™ Specifications

• Allowable temperature setpoints: 62 to 85° F depending upon room ambient

• Allowable RH setpoints: 35 to 75% depending upon temperature setpoint

• Control accuracy: +/- 1° F and +/- 1% RH

• Water Tray capacity: 2 quarts

• RH Mister capacity: Up to 6 oz. per day

Guitarmidor™ Performance

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Time Interval (Hrs)

Tem

p/R

H

Room Temp Cabinet Temp Room RH Cabinet RH

The Hardware behind the Science

• Custom Thermoelectric devices

• Peristaltic pumps

• Variable speed fans

• Variable current Power Supplies

• Custom designed Control system

• CFC free single device heating and cooling

• Accurate misting control

• Effective air management

• Adjustable and efficient load sensing

• Industrial quality components for long life

Protect your investment with Guitarmidor TM... Environmentally controlled, heirloom quality furniture.

Visit the Guitarmidor™ Website