Excerpt from Chapter 4: Constructing Cane Rods
By Ray Gould
Published by Frank Amato Publications
Thanks for use permission!
Bamboo (Tonkin cane) has some excellent physical
properties. These include light weight, elasticity, and high
strength. The following table shows some compartive data:
Please note that the data shown for bamboo is for Tonkin
cane which is the preferred cane type used for fly rods. From
this data one can observe that bamboo is actually stronger and
stiffer then wood and fiberglass while not being as strong as
some of the graphites. By way of explaination, the term
"modulus" is a measure of stiffness and is the ratio of stress
to strain within the elastic limit of the material. The elastic
limit is that point to which materials can be stressed without incurring
permanent deformation. Generally speaking the materials with a
higher modulus also have higher tensile strength. Perhaps an
easier way to look at this data would be in bar chart form.
The bar chart Fig.32 shows the tensile strength of
various materials, including Tonkin cane. It points out in
visual terms that bamboo is a highly suitable, if not to say
remarkable, construction material. In all fairness it should
also be pointed out that recent developments with graphite
have produced some even stronger materials, so graphite
has its place as well.
Bamboo has other characteristics that make it a good
material from which to build fly rods. It is relatively lightweight,
low cost, available, has internal resistance to resonance, and
resists failure from surface nicks. The specific gravity of
bamboo is about 1.15 which means that it's heavier than water
and won't float.
Because of its unique cellular construction, bamboo possesses
a self-dampening quality thereby absorbing vibrations. It is this
feature which allows the bamboo rod to cease oscillating after
a cast is made, an important quality in fly-casting.
Perhaps most importantly in a comparative sense is the
ability of bamboo to resist failure from surface nicks. It is
indeed a sturdy material. Certainly more than a few fishermen
have seen a graphite rod literally explode when heavily loaded.
This type of failure usually occurs at a place where the graphite
tube was nicked or scratched. What happens is that a "stress
riser" develops in the very thin wall (0.025") at that point causing
very high stresses and subsequent failure.
The Tradition next time!
~ Ray Gould