of tonkin cane.
Demarest. Copyright photos courtesy of Harold Demarest, Inc.
world produces over 1000 species of bamboo. Here in Louisiana,
there are acres and acres of wild bamboo. None of the local species
are suitable for making rods - believe me, I've tried! Tonkin
cane is farmed on plantations in a small area of southern China.
"Tonkin," or tea stick bamboo is the common name rod makers use
for arundinaria amabilis, the lovely reed. Few natural materials
are its equal in strength to weight ratios. In many Asian countries,
bamboo replaces steel in some construction projects. Tonkin grows
to 40 feet tall in one year. It is naturally straight, with no
branches and a slow taper. The prized "power fibers" found just
underneath the outer cambium layer, known as the enamel, are stiff
and resilient. As they grow, bamboo forms nodes from which leaf
branches protrude. Tonkin bamboo does not form leaf branches in
its lower sections. Each node, spaced from 8 - 20 inches apart,
is relatively flat and easy to manage. The Tonkin bamboo grown
on Chinese plantations is harvested every 8 - 9 years when it
is fully mature.
I get my
bamboo from Charles H. Demarest,
Inc.. Harold and Eileen Demarest have helped scores of rod
makers get their start. Bamboo comes from China in bales of 20
culms. Each culm is 12 feet long, and approximately 6 inches in
circumference. Ordering a full bale lets you work with 12 foot
culms. Try to get a culm or two of full length cane. The 12 foot
lengths make life simpler, and use the bamboo more efficiently.
Since it is shipped by common carrier, it isn't necessary to cut
the bamboo in half for shipping. Smaller quantities of bamboo
can be shipped via UPS but the culms must be sawn in half to facilitate
large, unsightly growers mark, highlighted in black. Marks
like this reach beyond the enamel layer and must be avoided
when splitting strips to use in a rod.
delivery, give your bamboo a thorough inspection. Some culms have
"growers marks" scratched into the outer enamel surface. These
marks are Chinese characters used by farmers to identify their
crops. The scratches usually penetrate through the enamel to the
power fibers, making that part of the bamboo less than desirable.
Don't despair, growers marks are usually limited to the butt end
of the bamboo, and rarely make the entire culm useless. You simply
split around the marks and use those strips which aren't disfigured.
bamboo grows crooked, the farmers straighten it over high heat.
Any charred areas on your bamboo must be noted. They will appear
dark brown to black instead of the golden tan color of natural
bamboo. When I find a burn mark, I circle it with a red marker
to remind myself not to use strips from that area. Also, I always
mark the very lowest end of the culm with a black marker to prevent
getting mixed up later.
raw culm with check split installed
the bamboo, a check split is installed in each culm. Left on its
own, bamboo splits and cracks as it dries. To keep those splits
and cracks manageable we give them a little help with a split
through one side of the bamboo from the butt to the tip.
the check split is simple. Search each culm for any cracks and
splits that have already begun. You may want to use a split that
Mother Nature started for you. If there aren't any splits, find
an old thick bladed knife to use as a splitting tool. Be warned
that you can easily break the high carbon steel of expensive huntingknives.
I use an old knife I bought for $6 twenty-five years ago. Even
new, it never held an edge well. You can purchase an expensive
bamboo froe, but cheap old knives work just as well. You will
also need some sort of mallet with which to strike the knife blade.
Breaking the splitting knife is not as likely with a mallet as
it would be with a hardened steel hammer. One more tool needed
here is a good pair of leather gloves. The split edges of bamboo
are razor sharp. Since you will be using a knife and mallet on
sharp bamboo and exerting a good bit of "elbow grease, this is
an excellent opportunity to cut yourself. There are lots of good
ways to cut yourself in rod making. This is one of the best. Unless
you are careful you can wind up with the mother of all paper cuts,
or much worse. Use common sense. Take your time. Be careful. And
keep some bandages handy, just in case.
best from butt to tip. Place the tip end of the culm against something
solid, like one leg of your workbench. Lay the splitting knife
against the one edge of the butt end of the culm. Orient the knife
so that its tip would split the exact center of the culm if it
were solid. Getting this angle correct now keeps things simple
down the line. Draw a line on the end of culm if it helps you
keep things straight.
Tap the knife
blade with the mallet. The split should begin to form easily.
Help the split along by twisting the knife from side to side,
always keeping the tip of the blade near the exact center of the
culm. At each node you will probably have to give the knife another
tap or two with the mallet. Extend the check split all the way
from the butt to the tip, one split per culm.
Honey blonde and a medium dark mottled flamed rod. Which one
do you like best?
properly filed and sanded node.
decisions need to be made before you begin splitting the culm
into strips. First, do you want a nice honey-blonde rod, a deeply
flamed rod, or something in between. My personal preference is
a medium brown, evenly flamed look. Flame tempering adds some
resiliency to the bamboo, and makes splitting a little less difficult.
tempering, the outer lip of each node and the hump above and below
the node is filed to reduce its prominence. Though I use a 1"
belt sander for this, I suggest you start with a 10" mill file.
Place the culm on your workbench and while holding the file perpendicular
to the culm, slowly file the outer lip of the node while at the
same time rolling the culm toward you. Don't let the edge of the
file to dig into the surrounding enamel. File until the lip is
nearly gone, then examine your work. You will probably notice
that there are distinct humps above and below each node, which
need to be reduced in size. To reduce their size, file at an angle,
again rolling the culm with each stroke to keep your work even
around the circumference of the culm. Keep the cutting surface
of the file on the bumps, not allowing the corners to dig into
the adjacent areas. When the area between the bumps is about 1/8"
move to the next node. Touching up all the file marks with some
220 grit sandpaper is a good idea. After dressing all the nodes
it's time to flame the culm. (Skip the flaming if you have opted
for a blonde rod)
culms with a high output, wide flame propane torch. I use a self-igniting
BernzOmatic TS 4000. A pencil point flame concentrates the heat,
but a wide, defused flame covers a large area with intense heat.
Major home and hardware stores often carry these torches.
the culm, work outside on a calm day. Lay the culm on your barbeque
pit, or across two metal chairs. Practice flaming on some scrap
bamboo. Flame some practice pieces to a very dark brown, almost
black. Then sand the enamel away with 220g sandpaper. You'll notice
that though the enamel looks ruined, the power fibers underneath
are beautifully colored. It takes lots of heat to ruin the bamboo,
but getting the hang of where to hold the torch and how fast to
move it takes a little practice.
flaming at the butt end, and work towards the tip. Move the flame
from the butt to just past the first node, then turn the culm
a little. Pass the torch over the filed nodes at the same speed
as you do over the enameled areas. With my torch, I cover an area
about 1.5" wide in each pass, covering the entire circumference
of the culm in four or five passes. I hold the torch about an
inch away from the bamboo, and move it two or three inches per
second. Never hold the torch too long in one place, or it will
scorch too deeply. One author says what you're doing is similar
to searing a steak, high heat for short durations. I try to keep
the torch moving at just fast enough to see the outer layer of
enamel "explode" as the torch progresses. I wish I could be more
specific, but this is one of those things you learn by trial and
error, hopefully on practice pieces of bamboo.
one node to just past the next, moving from butt to tip. When
you reach the tip end and see steam and moisture being forced
out of the end grain, you will know you have done a good job.
rod begins with selecting a taper and splitting the culm into
strips. Many classic rod tapers have been published over the years.
As your skills progress, you can begin to design your own tapers.
For now though, let's stick with one of my favorite classics –
a fairly quick 7'6" 2 piece 5 weight, lightly flamed. Since most
bamboo rods are built with two tips, you need 12 strips for tips
and 6 strips for the butt section of your rod.
only make rods of one length from each culm, I cut each culm to
length before splitting. In our example we're making a 7'6" (90
inch) 2 piece rod. The finished length for each section will be
a little over 45 inches. But if you cut the culm at 45" your strips
will be too short. Allowances must be made for staggering the
nodes and for extra working length.
the weakest part of the bamboo. Good rods never have nodes adjacent
to each other in finished sections. I've settled on a 2x2x2 node
spacing where each node is separated by two strips without nodes.
Allow a minimum stagger of two inches between nodes. Allowing
another 2 inches leeway on each end of the strip gives you a little
margin for error in planing and gluing the strips.
the numbers: 45" (strip length) + 2"+2" (extra at each end)+ 6"
(node stagger)= 56"
is how the nodes will be positioned when the strips are
glued together to form the rod blank.
you choose a different node spacing, adjust the length at which
you cut the culm accordingly. For our example, lock a tape measure
in place at 56 inches. Lay the tape next to the tip end of the
culm. Because the nodes are weak, you want at least 5 node free
inches at the very tip. Make sure the node closest to the tip
is at least 12" from the tip. If the uppermost nodes is not twelve
inches from the top, select another culm, or move down below the
first node. Mark the culm at each end of the tape measure. You
will take the strips for the tips from that part of the culm between
the two marks.
move to the node immediately below your lowest mark and mark the
culm just below that node. Starting from this mark, measure another
56 inch section, and mark it. Strips for the butt section come
from the part of the culm between these two lower marks. Extend
each mark around the circumference of the culm. (Felt tip pens
work great for marking on bamboo.) Now just for peace of mind,
measure everything again.
To cut to
length, over-wrap your marks with masking tape, and trace the
marks through to the tape. With a hacksaw or fine toothed coping
saw, cut the culm through the tape slowly to prevent tear outs.
Mark the end grain of the lower end of the tip section strips
with a red permanent marker. Make all your cuts the same way,
with the hacksaw and the tape. Mark the lower end of butt strips
with a black marker so butts and tips can be kept separated.
with the entire culm, then split in halves. Split each half
into thirds, resulting in sixths. Split each sixth into quarters,
giving you twenty-four strips
the split on a half node.
a half culm into thirds using the knife-in-vise technique.
the first split on a sixth-culm strip.
strips at least 1/4 inch wide allows plenty of margin of error
for splitting and node straightening mistakes. A culm of bamboo
6 inches in circumference will yield 24 strips 1/4 inch strips.
When building very large rods, start with strips a little larger,
perhaps 5/16 inch. The sequence goes like this: Split the culm
in half. Then split each half into thirds, yielding six one inch
strips. Then split each one inch strip into quarters, yielding
by dividing the culm in half, using the check split as a guide.
(Put on your heavy gloves. The split sides of bamboo are razor
sharp.) Center your knife in the check split, again holding it
perpendicular to the enamel. Keep the knife aligned in such a
way that every split passes through the exact center of the culm,
even when making the final splits. I use my big knife and mallet
until I have the culm in six strips. Once things are lined up,
give the knife a sharp whack with the mallet to get things started.
Twisting the blade should move the split forward from node to
node, though you may have to give the knife another whack or two
at each node.
splitting bamboo into equal parts equalizes the stress on each
piece and the splits run straight and true. – In theory. – In
reality, the splits try to wander from side to side, and left
alone results in some strange looking pieces. The solution is
applying enough body english to force the wider piece into an
arc. Bending the small final strips is fairly easy. Preventing
the split from wandering too far on large pieces tries ones patience.
Be willing to sacrifice some bamboo for the experience. By the
time you have split two or three culms, the process seems second
culm in halves, it's time to split each half into three pieces.
From this point forward I use a small knife held in a vise for
all my splitting. (I barely start each split with another knife)
Keeping the knife stationary allows me to use both hands to apply
all the bending pressure necessary to keep each split the correct
into thirds constant correcting pressure must be applied to keep
things in line. The thin bladed knife prevents the split from
progressing too far ahead and allows great control over the entire
process. Start the split, then press the bamboo into the knife.
Be sure to keep the knife blade traveling through the imaginary
center line of the culm. Take your time, and then slow down some
more. Don't forget your gloves. There are lots of good ways to
cut yourself while making rods. This is one of the very best.
And when you cut yourself, remember I told you so! Keep your wits
about you and you will do fine. Since you only need six pieces
for the butt, plus a couple of extras for good measure, don't
get too worried if some of the splits wander a little.
is divided into thirds (giving you six one-inch strips), and each
third (sixth) will be split into quarters, yielding 24 strips.
With 24 butt section strips as a goal, there is plenty of bamboo
to work around any growers marks or leaf nodes. To split each
sixth into quarters, start by splitting it in half. Then split
each half again. Again, mark each strip on the enamel side, and
take your time. These smaller splits into halves are actually
easier because each side is the same width and tends to wander
less. You'll still find the strips wandering occasionally. Bend
the unsplit portion of the strip towards the larger section, and
things will work themselves back in line. When you finish splitting
the pieces for the butt section you'll probably have 18-24 pieces
at least 1/4 inch wide. Too wide is okay, but will make for much
more planing down the line.
Each of these
strips will be split again. Splitting is only learned through
experience. Most makers find it very difficult at first, but soon
find themselves trying to squeeze a few extra strips out of each
culm so they can make more than one rod per culm. For now, though,
be content to get six or seven good butt strips and twelve to
fifteen good tip strips. If you accomplish that goal, then take
a break and have a strong cup of coffee.