Quck answer
Bamboo can be dried using two methods – air drying and kiln drying. Air drying involves cutting the bamboo and leaving it exposed to the air for several months, allowing it to naturally dry. This method is suitable for small projects and crafts. Kiln drying, on the other hand, involves using a specialized kiln to dry the bamboo quickly and efficiently. This method is ideal for larger projects and commercial use. It is important to properly prepare the bamboo before drying by removing the leaves and branches. Additionally, bamboo should be stored in a dry and well-ventilated area to prevent mold and mildew.
Bamboo, which belongs to the grass family (Poaceae) in the subfamily Bambusoideae, can be dried properly to ensure its long-term use. It is hardy in U.S. Department of Agriculture plant hardiness zones 4 through 12, depending on the species and cultivar. If not dried correctly, bamboo, with its high water content, can decompose quickly, be susceptible to fungi, and become a target for insects. There are three common methods for drying bamboo: heat drying, air drying, and soaking in water.
Harvesting Bamboo Culms
Prior to the drying process, it is important to harvest bamboo culms correctly to prevent splitting. It is recommended to only cut down culms that have been growing for at least three to five years, as it takes this long for the plant to fully harden. This hardened bamboo will shrink less when dried and will be less vulnerable to insect damage. For optimal results, cut the bamboo in the fall or winter when the sap is not actively moving. Any cutting tool can be used, such as a chainsaw, reciprocating saw, or hacksaw, but it is important to cut the culms just above a node to avoid crushing or splitting.
Air Drying the Bamboo
Air drying is the most commonly used method for drying bamboo due to its simplicity and cost-effectiveness. After cutting the bamboo culms, store them vertically or horizontally without removing any leaves or branches. The leaves and branches provide a large surface area for evaporation. It is best to store the bamboo in a cool and shady area to ensure slow evaporation and prevent cracks and splits. Another option is to store the culms horizontally on racks that allow air circulation. Rotate the bamboo every two weeks. The drying process can take six to twelve weeks, depending on the size and moisture content of the culms.
Heat Drying the Culms
Bamboo can be preserved using its natural resins or oils. To heat dry bamboo, place sections of newly cut bamboo over red-hot charcoal or another heat source that can reach 250 degrees Fahrenheit. Use a grill with a rack to keep the bamboo a few inches away from the hot coals. Monitor the bamboo closely to prevent it from catching fire and use heat-resistant gloves and safety goggles for protection. As the bamboo is heated, the resin will appear on the surface and can be wiped away with a cloth. This process helps seal and preserve the surface while allowing moisture to be removed. Heat one section at a time and once the bamboo changes color and the resin has been wiped away, place it in a rain-protected and well-ventilated area to dry for two weeks. Heat drying is a reliable method to prevent cracking or splitting during the curing process.
Immersing Bamboo in Water
Another technique for drying bamboo involves immersing the culms in water. Prior to submerging the culms, it is necessary to puncture each of the nodes to allow water to penetrate all parts of the bamboo poles.
Completely submerge the bamboo in a continuous flow of water or in a container. Use heavy boards or rocks to weigh down the bamboo and ensure it remains submerged. Allow the bamboo to soak for a duration of 12 weeks to fully saturate the plants, and then place it in a sunny location to dry. If storing the culms in a container, it is recommended to change the water on a weekly basis to prevent the growth of bacteria and algae. Additionally, you may choose to add borax, boric acid, or other preservatives to the water.
Soaking the bamboo serves multiple purposes. It protects the bamboo from insects during the drying process by extracting starches that insects would typically consume. Moreover, it uniformly saturates the plant with water, balancing the moisture content. As the bamboo dries, the water evaporates gradually and evenly, thereby reducing the likelihood of cracking and splitting, even in higher temperatures.
