Humidity Basics

The Care & Feeding of Froggy Bottom Guitars
Part II: Humidity Basics: Protecting the Instrument Body

These are not fragile instruments; they are responsive. There are a lot of Froggy Bottom Guitars out there in the world. They move around and respond to their environments as they respond to your touch. We can’t limit their environmental responsiveness without sacrificing their musical responsiveness.

“When it comes to humidity, stability is the key, no matter what the (reasonable) range.  The guitar will eventually settle in.” Too much humidity, or too little; too high a temperature, or too low will affect the instrument for good or ill.”

– EG

Two related facts: in the presence of moisture, wood will swell; in its absence, wood will shrink.

These are key to understanding how to manage and maintain fine wooden instruments.

When you glue up a guitar sound box, the structure limits the wood’s ability to move. If it has too much moisture in it to begin with (whether from inadequate drying or from too humid a shop environment), when the instrument encounters an environment that is seasonally or geographically dry, the wood will shrink, pull against its glue joints, and may run the risk of cracking or splitting.

Froggy Bottom Guitars are built in shop environments that for eight months of the year are under 20% humidity, and at the height of summer, under 30%. The instruments are built with aged air-dried woods that have very low moisture content by the time they are fashioned into instruments. They are very stable when they’re glued up.

By building with high quality woods with extremely low moisture content (achieved by air drying, not kiln drying) in a dry shop environment, the instruments can be successfully maintained in a wide range of environments.

“Our guitars go all over the world. They are sold to owners in Australia, Europe, Alaska, the Texas hill country, the desert Southwest, as well as to owners in Seattle, Washington or Cape Cod, Massachusetts.

“These instruments are built in a very dry environment. We want them to be super-stable when they’re put together as they have to serve their owners well in all these different environments.

“Here in the Northeast, and in northern climates where we heat with wood or oil in the wintertime, the air gets really dry both inside and outside the house. In these environments, you have to take care.  You have to ‘water’ your Frog on a regular basis.”


Instrument Humidifiers

We use and recommend the Kyser ‘Lifeguard’ sound hole cover humidifiers (available at These hold a small sponge that can be wetted and wrung out.

The Kyser sound hole humidifiers help seal and humidify the air inside the body of the guitar. They are a much more direct and specific way to humidify the instrument than other reservoir systems that a might include a small container of water in either inside the case, or worse, the body of the instrument.

“In the dead of winter, I check my Kyser sound hole cover humidifier twice a week. I’ll wet the sponge then give it a good squeeze. You don’t want it dripping wet. You do not want moisture loose in the guitar. We like these humidifiers because they seal the body of the instrument and have no reservoir to fail.”

– EG

Any humidifier designed to allow you to ignore your guitar is dangerous.

Humidifiers that hold a reservoir of water that might humidify the guitar for a week or more can fail and they hold enough water to destroy the instrument. Why would you want to ignore their guitar for a week anyway? The instruments profit from and require attentiveness.

Temperatures: Hot

Heat and moisture are the elements employed to bend guitar sides into their lovely curves, but these are not forces one wants to turn loose on a finished instrument.

We’ve dealt with moisture extensively, now, for heat and cold.

Extremes of temperature can endanger fine, wooden instruments.

Heat can warp and deform parts of the instrument and weaken glue joints. It can turn loose forces that the structure and materials of instrument will simply not survive.

Setting your guitar case down by a roaring woodstove or leaving it in what used to be a shady spot at a festival, only to come back and find it in the full sun in a dark case can shorten the working life of the instrument quickly and dramatically.

Temperatures: Cold

Allowing it to freeze – or anything close – is similarly dangerous. Should your guitar get cold, we caution you against rushing it into a warm room and throwing open the case. Temperature shocks can ruin guitars in a variety of ways, structurally and cosmetically. Take care if your instrument has been consigned to the belly of an airplane. It’s cold at 35,000 feet.

If it has been shipped in the winter, don’t unpack it. Give it a day, literally.  Then open it’s external box and let it breathe. After some hours, get the guitar in its case out of the packing materials. Take your time. (This is easier said than done, especially with a new, custom Froggy Bottom.)

Let the instrument and its case come gently and gradually to room temperature before you open it.

If the handle of the case is colder than your kitchen table top to the touch, or the wooden back of a chair, wait. It’s senseless to damage or ruin an instrument by being impatient.