Did you forget your dampit?

dampit humidity

It's summer festival time, and chances are you are traveling to an area where the air moisture level is drastically different.

Some of you may have already noticed cracks forming on your instrument, but for some of you, there is still time to prevent instrument cracks from forming with the use of a dampit.

But before I get into why dampits prevent instrument cracks, it's important to understand why string instruments crack due to weather in the first place. 

Why does my instrument crack?

First, we have to understand how wood responds to air moisture. 

Wood is hygroscopic, which means the wood itself acts like a sponge that can absorb and release water. 

The cracks form when wood shrinks, and for wood to shrink, it must release water.

For wood to lose its water content, It must be exposed to an air moisture level that is lower than what it has adapted to. In other words, the moisture within the wood will continue to evaporate until it has reached equilibrium with its surrounding environmental air moisture level. Once the wood moisture content level has reached an equilibrium state with its environment, then it will no longer gain or lose moisture.

For example, let's say you live in New Orleans, but you are going away for a summer music festival in Denver. If the air moisture levels are higher in New Orleans, but lower in Denver, then the wood of your instrument will eventually shrink if you move from New Orleans to Denver, causing possible cracks to form while your instrument wood is shrinking in Denver Colorado. 

How can I stop the wood of my instrument from shrinking to avoid cracks?

The most practical (and economic) way to prevent the wood of your instrument from shrinking is to get a dampit. 

What is a dampit?

A dampit is made up of three parts:

  1. Sponge: material used to absorb water; located inside the tube.
  2. Tube: encases the sponge; has holes that allow moisture from the sponge to evaporate inside the instrument.
  3. Plugs: prevents water from leaking outside the tube.

parts to an instrument dampit

How does a dampit work? 

Once placed inside the instruments f-hole, the dampit will act as a humidifier by allowing the water in the sponge to evaporate inside the instrument. By consistently placing the dampit inside the instrument, you stabilize the wood moisture content level, preventing the wood from shrinking and causing cracks. 

For the dampit to work, you must run water over the permeable tube until the sponge is fully soaked. The clip below is a simulation of how the sponge material reacts when you run water over the dampit.

Image result for water evaporating from sponge              

What happens if I don't have a dampit? 

If your instrument is subject to lower air moisture levels while traveling, your wood will shrink, and if left unchecked long enough, it will eventually crack. Take a look at the image below of a woodworker leaving timber out to dry. As you can see, the cracks formed over time during the drying process. 

Image result for cracked timber


How can I get a dampit for my instrument? 

There are two ways to get a dampit. You can 1) buy them from your local luthier shop, or 2) you can order them online. below you will find a list of dampits that are specially made for the violin, viola, cello, and double bass; they all can be purchased from Amazon.  



to recap, when your instrument wood is exposed to lower air moisture content levels, it is subject to wood shrinkage, causing cracks to form over time.

The best way to prevent instrument wood from shrinking is to get a dampit. A dampit stabilizes the moisture content of the wood, which prevents the wood from expanding and shrinking. 


If you have any more questions regarding dampits and the effects of weather on string instruments, then please feel free to leave your question in the comment section below.


-Xavier Foley

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