The influence of the weather

Wood expands when humidity is high and shrinks when it is dry. This can cause all kinds of problems. The wood of the plates behaves differently from the ribs and tension develops at the seams. As a result you get open seams. This is actually supposed to happen, because if the seam doesn't open you'll get a crack instead, which is much worse. Cracks also often appear next to the lower nut and neck. Another problem that develops when it is dry is that the fingerboard rises closer to the strings, this is especially noticeable for cellos and basses. Some players use different bridges in summer (usually more humid) and winter (usually dryer). I already mentioned pegs slipping or getting stuck. Your instrument will generally be fine in the same environment you feel comfortable in. Avoid extreme temperatures, dryness and humidity and sudden changes. 50 to 60% is often given as a good level of humidity. I find heating in New Zealand homes in winter quite erratic and haven't really figured out how to keep my instruments happy in this environment yet. I'd be very happy to hear from anyone who has found a good system.

If your main problem is dryness, Michael Bauer, a cellist from Yukon Canada has suggested a solution that works well for him in his semi-arid climate: I solved the problem quite successfully by constructing a humidor. Starting with a base plate of 3/4 inch plywood 15 inches by 20 I fastened four upright broomsticks (actually 1 by 1ns) 68" long to each corner with a 2" wooden screw and placed another plate, same size as the floor, to the top. This allows the cello to hang free from a wire loop in the center of the top plate. Then I wrapped the whole structure with thin plastic from the hardware store. After stapling the four corners I am using a fifth stick to the end of the plastic as a door opener, wrapped and stapled. To hold the door closed I use a short bungee cord hooked into eye screws. To maintain a constant humidity I placed a one gallon or so ice cream bucket in the back corner of this humidor with a double arch of coat hanger wire in this bucket and draped a tee towel over it. To monitor the humidity I use a cheap hygrometer which I can check right through the plastic. This contraption has worked well for me for the last 20 years. To keep the water in the bucket from getting moldy I use a little bit of hydrogen peroxide occasionally.

If your temperatures are a bit up and down though, be careful about condensation. He suggests adjusting humidity by leaving an opening in the closing partition of his humidor and adjusting its size.