How did the grandmother bend the bamboo into circles.?

Answer 1

There are three ways to bend bamboo. One method is to soak the bamboo rods in lukewarm water for a period of time, usually twenty-four hours. After it has been soaking take it out and test it by gently bending. If you hear a crackling noise the bamboo needs to soak longer. If there is no crackling sound take the bamboo and place it on your shape board. Place a nail on each side of the bamboo about one inch apart following your desired design. Let it sit on the design board for about three days until it totally dries. Once removed from board it will retain its shape. The second way to bend bamboo into circles is use a knife and cut a V shaped notch in the bamboo at the joint or node of the bamboo. The more narrow the cut the curve will be slight, the wider the cut the more dramatic the bend. With this method you can cut as deep as two-thirds into the diameter of the pole. After doing this gently bend bamboo into desired shape and secure with tape or string. The third way to bend bamboo into a circle it to use heat. Because each piece of bamboo has internal nodes you must first knock them out by using a rod or bar to break them out. On the outside of the bamboo nodes a few holes will need to be drilled to allow vapor to escape from the pole when the heating process begins. A torch is used with a flame that is as hot as the boiling point. The flame needs to move up and down the bamboo. As the rod warms a coffee color will appear and stains the rod. The pectin and lignin at this point becomes soft allowing the bamboo to bend more easily. Use a wet rag to check the pliability of the rod and to wipe any extra moisture off. If it will bend plug on end of the bamboo and then fill rod with sand. This is done so that the rod will bend with out buckling the bamboo. The sand is used to stabilize the rod. Dig a hole about eight inches deep and place one end of the bamboo in the hole. Begin placing the flame to the rode and concentrate on the area that you want bent. Don't forget to wipe the pole with a wet rag occasionally. This will keep the bamboo from drying and becoming brittle. Repeat this process until desired shape is reached. Take time doing this so that the stress it is under will not cause splitting.