07/22/2024
PSA FOR ACOUSTIC GUITARISTS: It's that time of year for a reminder that despite the relentless and brutal humidity outside, we are running our AC units more often to try and beat the heat. The more your AC operates = The more it sucks the moisture out of the air AND your instrument, the same way a heater does in winter.
As temperature increases, wood expands. Your instrument is made of different types of wood, in different thickness, some parts with a finish, some open grain, so certain parts are more sensitive to this effect than others. As wood dries out and moisture drops, it shrinks/contracts. When temperature increases as humidity levels decrease, some parts want to expand while other parts want to shrink. This creates a unique stress on the instrument as strings, truss rod, and bracing are pulling and contorting it one way while temperature and humidity are squeezing and swelling it in others.
This can wreak havoc on your beloved axe. Lifting the bridge, bracing, finish delamination, separating the fretboard from the neck, splitting or cracking in the body, and at the very least develop fret sprout or trash the setup specs.
These problems are easily avoidable with some simple steps and routine checks.
#1 Use your eyes. If it looks dry? it is....
#2 Hygrometer's are cheap and easy to use, buy one...
#3 If you simply cannot afford a new tool, find something with a straight edge you know to be true, check it on a window or piece of glass to be certain. Lay the straight edge across the body (up against) the rear of the bridge, from the center of the body to the edge of the body. You are looking for a gap under the straight edge between the edge of the body, and the side of the bridge(area in photo indicated by RED line). If there is a gap? it's too dry...
There should be no gap at all, straight edge should be flush with the body top from rear center of bridge all the way to the edge of the body (indicated in photo by BLUE line).
An acoustic guitar top acts like a speaker cone, it is radiused by design so that it pumps air/soundwaves in & out the sound hole using energy/vibration created by plucking the strings. When this radius is strained and contorted, it affects not only the playability of the instrument, but the overall sound clarity and volume projection as well.
Conversely if the instrument is TOO saturated with humidity it can be just as detrimental. Symptoms such as a dull, dead tone, low volume, corroded/oxidized hardware & frets, and difficult playability can start to appear. However it is important to note that TOO MUCH humidity isn't half as bad as TOO LITTLE.
So you'd better get into the habit of checking these things regularly or you will be shelling out your hard earned cash to people like me to fix it. And if you let it get too bad for too long? There isn't anything anyone can do to repair it and then it's all over but the crying...
Do yourself and your instruments a favor and keep em cool! Keep em moist!
