How to Prevent Cracking
Cracks in stringed instruments can have a variety of causes. Foremost is poor construction and/or mechanical design. Perfect wood cannot save a badly built or conceived instrument. Conversely, a beautifully crafted and designed instrument can crack due to environmental forces beyond the control of the lutherie.
The real threat to a harp is dry air. The string pressure on a Rees Aberdeen Meadows Concert Line harp is nearly 1200 lbs (544 kg). That is, essentially, a 1200 pound horse standing on a 1/4 inch (.635 cm) thick piece of wood! When wood dries out it becomes more brittle. For any stringed instrument, brittle is bad.
There is some basic science which will help you to better understand how to protect your harp from cracking. Humidity is a measure of how much moisture is in the air, in other words, the percentage of air molecules which are bonded to water molecules. When there is too much water for the air to support you need an umbrella. When there is very little water in the air your harp is at risk. As a side note, if there is too little humidity you may find yourself needing things like skin moisturizer and lip balm more frequently. Also, any air which is too dry for your harp isn’t helping the wood in your furniture or home either. The cellular structures of both wood and skin need a certain amount of moisture to remain resilient.
One would think then that in places like the American Midwest and South harps would be safe during humid summer months but because humans are uncomfortable in high humidity we use air conditioning. Cold air carries less water. That is why winter air and summer air conditioning are equally problematic for your harp. Of course those harpers who live in environments that are dry, as is much of the American West, have an even greater need to compensate for a lack of humidity.
The optimal answer for this is to humidify your home but that is an expensive proposition. What is easier is to raise the local humidity for your instrument. In the past, when Rees Harps was small enough to be located inside William’s home, he kept a giant bowl of water close to the harps during the critical times of the year. There are also some new products on the market made specifically to provide humidity to stringed instruments. We are testing those so stay tuned!