With the heat of this Summer in the Detroit area, it is important to be aware of how one can protect their instrument. The worst thing that an instrument owner can do is leave their guitar out in a car on a hot day. You wouldn’t leave your child or family pet out in a car in these elements, or it would surely die, and in essence, so will your guitar. Extreme heat can cause moisture to evaporate and leave the wood of an instrument, causing it to crack. Heat like this causes necks to warp, and finish to stick to the material inside of an instrument’s case, but most disturbing is the way that heat can melt glue.
On a hot day like this, the inside of a car parked in the sun can reach an excess of 175 degrees Fahrenheit in only fifteen minutes. That is seriously hot! Not to mention that the glue used to hold most modern instruments together is an aliphatic resin wood glue, which literally turns to liquid at around 140 degrees Fahrenheit. This means that your guitar, which was carefully constructed with induced tension in the joints, and has 179.2 pounds of tension being placed on the bridge by the strings (A standard set of light gauge strings will apply a total of 179.2 pounds of pressure on the bridge. This measurement will vary depending on the specific gauge that you are using on your instrument), will not only come apart, but will do so with force. Even a classical guitar can have a string tension of 75-90 pounds.
It is not uncommon to see the bridge “sling-shot” off of a guitar’s soundboard in extreme heat. This is more often the case with classical guitars, as the strings are tied to a block on the bridge itself, rather than through the soundboard with bridge pins like on a steel string acoustic guitar. As a matter of fact, the strings on an acoustic guitar going through the soundboard are often all that holds the guitar together after extreme heat exposure like that. Most of the time, the bridge is about a quarter inch off of the soundboard, lifted from back to front, with strands of glue leaving tell tale signs of exactly what occurred. These strands of glue are left because the glue becomes a liquid allowing the bridge to lift, and then it dries leaving the bridge in the lifted position. What’s worse is that frequently when a repair like this comes in to the shop, the braces on the inside of the instrument have the same sort of damage. They, too, are glued on with an aliphatic resin and can come loose in the heat.
Ultimately, do yourself a favor and just don’t leave your guitar in the car. Unless, of course, you WANT to pay someone like me to fix it. I don’t mind at all, and am more than willing to do the work.
By: David Bolla
Grosse Pointe Music Academy Staff