Wood Moisture Content
Wood moisture content (MC) is a critical factor that affects the characteristics and durability of wood. It is expressed as a percentage of the weight of water in the wood compared to the weight of the dry wood. The MC of wood can vary depending on several factors, including the species, growth conditions, and storage environment.
How Dry Should Wood Be Before Turning?
When turning wood, it is essential to ensure that the wood is appropriately seasoned or dried to prevent cracking, warping, and other defects. The ideal MC for turning varies depending on the species of wood and the intended use. However, as a general rule of thumb, most hardwoods should have an MC between 6% and 12% before turning.
Moisture Mapping Techniques
Several techniques can be used to assess the MC of wood, including moisture meters, resistance meters, and gravimetric analysis. Moisture meters are commonly used to measure the surface MC of wood, while resistance meters can provide a more accurate assessment of the internal MC. Gravimetric analysis involves drying the wood in an oven to determine the weight loss and calculating the MC based on the difference in weight.
Impact of Moisture Content on Turning
Excessive MC in wood can lead to several problems during turning, such as:
- Cracking: As the wood dries, it shrinks, which can cause cracks to form in the wood fibers.
- Warping: Uneven drying can cause the wood to warp, making it difficult to achieve a desired shape.
- Difficulty in cutting: Wet wood can be more difficult to cut cleanly, resulting in irregular surfaces and increased wear on cutting tools.
By appropriately seasoning wood to the correct MC before turning, woodturners can minimize these problems, enhance the stability of the wood, and improve the quality of their finished products.