Are Some Guitars Better Suited for Certain Climates?

Q: I recently bought a new, factory-made 000 with a torrefied Adirondack spruce top and a light satin finish. I spend each summer and fall in Nova Scotia near the ocean, so I have learned to keep my instruments in their cases with Humidipaks to avoid humidity issues. Even though I did this to my new guitar, the action went from .085″ to .15″ in a heartbeat. At first I blamed the gig bag for not protecting my guitar, but a luthier suggested that because of the finish, the instrument is highly susceptible to moisture acquisition and not suited to a Canadian climate. This is a shame considering I thought I had found my holy grail—it is beautifully made and has the loveliest tone I’ve heard in a smaller guitar. This raises the question: What climate is my 000 good for? And are certain guitars better suited for certain climates? —Scott Waldie

A: I’d like to commend you for a few things: first and foremost, for attending to the guitar’s humidity, and beyond that, for thinking through what might be happening, taking concrete measurements, and consulting a luthier to get an informed opinion. These are all great first steps, and I wish all of my repair clients would follow your example.

Let’s begin with the question as you present it: What climate is your guitar good for? Most factories these days anticipate that their instruments will end up in widely variable environments, and that humidity control will not necessarily be available in all situations. As such, most tend to assemble their instruments at a temperature/humidity combination that falls somewhere in the middle of the likely range the guitar might experience over the course of a year—usually, somewhere around 45 percent relative humidity at room temperature.

If the issues you’re experiencing are indeed humidity-related, they should be relatively easy to diagnose. “Wet” guitars (i.e., those that are overly humid) tend to have problems with higher action, convex tops that are bulging outward, and sluggish or dull tone. By contrast, “dry” guitars tend to have flattened or sunken tops, low action, and sharp protruding fret ends, and frequently will exhibit a hump or high spot on the fretboard extension where it meets the body. Frequently, people bring me instruments for buzzes and setup issues, all of which are resolved by simply rehydrating the guitar for a little while. This takes longer than simply leveling the frets, but, as I often have to explain, if I adjust the setup for a dried-out guitar, it will be back to unplayable in the spring, and those formerly high frets will now be too low—a much more irritating problem!

Returning to your original question: my opinion is that most of the humidity interaction happens on the unfinished interior surfaces, and not the exterior of the guitar. Though your instrument has a thinner satin finish, nearly any sprayed finish will act as a vapor barrier, so I am not inclined to blame the finish primarily. The torrefied top on your guitar has undergone a baking process which, according to some, reduces the tendency to react with changes in humidity. This process purports to offer a broken-in or aged tone by thermally modifying the structure of the wood’s cells. Developed in Scandinavia for architectural materials such as exterior decking and siding, this technology can indeed yield very water-resistant materials, but the levels of thermal treatment being used for tops are much more gentle than what is used for building materials, as it can reduce the strength of the material if overdone.

Because your guitar is brand new, it’s entirely possible that the change in action may have come from an initial settling-in period, in which the top, back, and overall structure of the guitar stretch and shift into an eventual equilibrium point. Since you report that the guitar sounds good, it’s likely that it is built lightly enough to give a lively response from the small parlor body. Lightly built guitars can take weeks or even months to settle in after initial assembly, as the string tension pulls the top forward, flattens the back somewhat, and rotates the bridge. This is a real challenge for builders at the factory scale—shipping guitars that play well right away can sometimes mean that a setup and saddle adjustment will be necessary within months, often while the instrument is still on a hook in a retail shop. Once we consider that some retail shops are in Arizona and others are in Florida, and that the same factory has to send playable guitars to both at the same time, the challenges become clear quite quickly!

Ultimately, your guitar should be able to work for you in whatever climate you call home. You’re on the right track using a two-way humidity solution (the Humidipak adds or removes humidity as needed, which is a minor miracle for guitar maintenance) and keeping the instrument in its case when not in use. The gig bag will not create the same enclosed environment as a hardshell case, so consider upgrading to a hard case—inexpensive molded cases are actually quite good in this regard, due to their plastic construction.

A competent luthier should be able to set up your instrument for your humid months. Some of my clients even keep low “summer” and high “winter” saddles, which they switch out themselves as the seasons change. Because you love the guitar, it is worth the investment to take it to a reputable luthier for such a solution. It’s quite possible, or even likely, that future seasonal variations will not be as extreme as those you experienced in the first few months of the guitar’s life, so once it’s properly set up, you may find that only small tweaks are necessary in the future. However, I strongly suggest waiting at least a few weeks in any given environment before altering the saddle or making other similar setup changes—otherwise, you may be trying to hit a moving target. By all means, continue with your proactive maintenance like humidity control and measuring action to stay aware of the guitar’s changes—these are exactly the best practices that will ensure a long and healthy life for your instrument.

This article originally appeared in the March/April 2024 issue of Acoustic Guitar magazine.