Bamboo Bonzai
Building a Bamboo Rod
by Thomas Penrose
All images and text copyrighted
We thank Thomas Penrose for use permission

July 13th, 1998

Culms of 2" diameter Tonkin cane. To make a rod, a single culm will be split into long narrow strips that will then require heat straightening at each of the nodal areas (the nodes are the raised rings that are visible on the outside of the bamboo plant). Only after this treatment can the cane be planed to form the tapered strips that the finished rod will be composed of.

Tonkin Cane Culms

Cane Strips

Some freshly split strips of Tonkin cane. The protrusions are the remains of nodal diaphragms, which occur inside the hollow bamboo stalk at each node location. They will be planed away, and then heat and pressure will be applied to flatten each node.

This node areas of this strip has been straightened with heat and pressure in a vise. The lightly charred area is where the heat was most concentrated. This dark area will be removed by planing in the next steps.

Straightened Node

A Single Strip

A single strip of cane in the preliminary planing form. The approximately 82 angle of the groove in this wooden form helps to start the first 60 angle on the raw bamboo strip as it is planed. After this 60 angle is created, the strip will be placed.
A strip in the 60 groove of the secondary planing form. Planing in this form will make the strips become equilateral triangles in section. Secondary Form
Checking Accuracy Checking the accuracy of the 60 angles using a center gauge.

These bundled strips have been through the secondary stage of rough planing. Their ends now have the equilateral triangle shape that enables the strips to nest together to form a rod that is hexagonal. They will next be bound together with string and placed in a heat treating oven that will dry, straighten, and temper them. Note that the side of each strip that faces out still has the original enamel layer that serves as the protective natural coating on the outside of the bamboo stalk. The side of the strips that have this coating is never planed, since the bamboo plant's most elastic fibers lie just underneath this thin enamel layer. The enamel will, however, be sanded off with fine grit sandpaper in the last stages of the rod's creation.

Bundled Strips

Ready to Heat Cure

The six untapered triangular strips bound together with string, forming the resultant hexagonal cross section that is typical of bamboo fishing rods. The string binding will cause the strips to heat cure in a straightened position, thus removing most of the kinks that each strip may have originally had. Most importantly, heat treating drives out excess moisture, and stiffens the cane somewhat. Many builders believe that placing the rod section in an iron pipe that is then heated with a blow torch serves this function as well as a more expensive oven does.
After heat treating, the bamboo strips will go through a final planing phase on a set of adjustable planing forms made from two steel bars (adjustable wooden forms can also be used for final planing). The beveled edges of the bars create a 60 groove down the center of the form that is adjusted in depth by tightening or loosening bolts that draw together or push apart the two sides of the form. The depth of the groove at each point along the length of the planing form is what determines how much the strips will taper from the large butt end of the rod to the smaller tip end. This adjustment is done on the planing forms using the pictured dial indicator depth gauge. There are an infinite number of possible rod tapers that can be used, and to a great extent being a good rod builder involves understanding how different taper designs effect the casting performance of any given rod. Dial Indicator Depth Gauge

Final Planing Form

The taper being planed into one of the bamboo strips using the steel planing forms and a block plane. The side of the form shown is for planing the larger diameter butt section of the rod. The other side of the form has a shallower groove and is used for planing the tip section
The strips sometimes tend to tear at the irregularly grained node areas during planing. To smooth these areas out a scraper plane is used. Scraper planes are also often used to remove the last few thousandths of an inch of material to make the strips flush with the top surface of the steel planing form. Inexpensive hand held scraping blades will also work well for rod
Scraper Plane
Binding Machine The bamboo strips being bound in a Garrison style rod binding machine. This is a simple yet ingenious mechanism that binds the strips tightly together when they are glued, which helps to make the glue joints between each strip invisible. However, it is also possible to do a good binding job by hand, without the aid of a binding machine.
A close-up of the binder. Binder Close-up
Bound, Glued Strips The glued strips after having gone through the binder two times (once to apply a clockwise wrap of thread, and again to apply a counterclockwise wrap). Note the excess glue coating the rod blank. This will be sanded away in the next stage.
The finished rod blank after sanding with fine grit sandpaper to remove the leftover glue from binding.

After Sanding

Finished Rod

Finished Rod

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