Bamboo Joinery 3

Here is an alternative joinery technique I just found on the web. It has a number of advantages over the technique I planned in the previous post:

• It doesn't rely on glue anywhere
• It doesn't use expensive hardware (hanger bolts, at 50¢ each, add quickly)
• It doesn't compress the bamboo as a bolt does, something the literature says is not good for bamboo.
• It doesn't require one to make a precise fit between a dowel and the bamboo interior.

On the other hand, it does require one to make a careful joining tenon, to drill the bamboo four times rather than one (which has proven tricky for me), and to fit pins precisely. Here it is:

1. Use a dremel cutting wheel or similar tool to cut a slot in the main pole, the dimensions of the tenon you will make. Make another cut in the end of the cross-pole the length of the tenon.
2. Make a tenon out of plywood the thickness of the slots (mortises) you have just cut. I show above a triangular tenon, which would give more support for bending of the cross-pole, but requires the slot on the main pole to be slightly longer than the joint, leaving it visible. A rectangular tenon, the width of cross-pole, would not have this defect. Insert this tenon into the two mortises and close the joint.
3. Drill four holes through the bamboo and the tenon, making sure that the joint is very tightly closed as you do so. Two holes lengthwise on the crosspole, and two lengthwise on the main pole.
4. Cut four pins and insert into the holes. You may use a weatherproof glue to hold the pins in place. This glue does not hold the joint: no force applied to the joint is resisted by the glue, but it does prevent the pins, that hold the joint, from working loose. What to use for the pins? Smaller-diameter bamboo is recommended. In some applications, bamboo skewers from grocery aisles are all that is needed, and have the advantage of being a consistent size. I think they are too small for my purposes, however.

I neglected to include in this illustration that you ought to first cut the crosspole end into the shape of the bamboo mainpole (see Bamboo Joinery 2, below).