How Much Does Humidity Affect Wood?

Humidity is a key factor in determining the moisture content of wood, and has a direct bearing on the stability and durability of the wood.The book covers everything from humidity monitoring to drying methods to solutions to common problems, and helps woodworkers avoid warping and cracking, and improve the quality of their products.

The invisible control of humidity.

Many people think that cracks and deformities in wood are the result of poor craftsmanship, but humidity is actually the main culprit.Wood is like a "sponge," which absorbs moisture and swells in humid conditions, and dries out and shrinks in dry conditions.This repeated swelling and shrinking eventually leads to cracking or warping.So controlling the moisture content is a battle of wits and wills with the humidity.

The first step in the process is to get to know the "temperament" of the wood.

The reaction of different woods to humidity varies greatly.For example, the moisture content of pine changes rapidly, while that of redwood is relatively stable.It is suggested that first a small experiment be done: place the wood samples in different humidity environments (such as a bathroom and an air-conditioned room) and observe the shape changes over a period of 3-5 days.This allows for a more intuitive understanding of the characteristics of the material at hand.

Choose your tools: hygrometer and moisture meter.

The accuracy of the temperature and humidity gauges used in the kitchen is not enough. It is suggested that industrial-grade humidity gauges (with an error of within ± 3 %) be selected.When measuring moisture content, a pin meter is more reliable than an electronic one, especially for hardwoods, which are so dense that an electronic probe can easily give a false reading.

Three steps to stabilize humidity levels.

Closed-space humidity control.

Small studios can use a closed container with desiccant.A hygrometer is used to monitor the humidity, and the desiccant is replaced if the humidity rises above 50 %.They are low-cost and are suitable for storing semi-finished products or precious woods.

The secret of ventilation.

Many people know that ventilation can reduce humidity, but they overlook the importance of timing. Humidity is generally high in the morning, so it is recommended that you open the windows between 2 and 4 in the afternoon, and use a fan to create air circulation. This is twice as effective as leaving the windows open all day.

A money-saving approach.

A large dryer is too expensive? Try converting a used refrigerator. Take out the cooling system and install heat lamps and a fan.The cost for processing a standard piece of wood is less than NT $ 1,000.

I've already fallen into those traps.

In northern areas, do not rush to turn on the heat in winter, as this may cause the outer surface to dry out too quickly.

• In the rainy season, a few bags of quicklime in the corners of the studio are more energy efficient than a dehumidifier.

• Before joining panels, make sure there is no more than a 2 % difference in moisture content. Otherwise, the wood will warp within half a year.

There is no silver bullet for controlling moisture content. The key is to keep a close eye on the crop and keep detailed records.I'm used to marking each batch of wood with the humidity at the time of purchase, as well as the moisture content before and after processing.If you persevere for six months, you will have developed the "touch" to predict the changes in the wood.