Selecting A Fine Piece of Bamboo

Getting in a fresh shipment of bamboo is like Christmas morning for me. I can't wait to rip off the shipping plastic and inspect the stock. At that point, it's all about the possibilities. I don't so much look at it for what it is, but rather for what it could be. It's important to start with a good piece of bamboo. I swear that a good rod maker instinctively knows the difference between the fine and the merely adequate, but here are a few specific things to look for.

Species
Start with the right species of bamboo. It's called "Tonkin". It comes from China. There are two brokers in the United States that deal in premium Tonkin cane for use by rod makers: Andy Royer and Charles Demarest. I prefer the quality of Royer's stock, but it is more expensive. There are other species of bamboo out there that are of interest to the rod maker: Madake (Japan) and Calcutta (India, Bangladesh, and Burma). Don't bother experimenting with these until you get it right with Tonkin.

What You Get
The bamboo that you get from a broker comes in twelve foot long culms. A culm is a harvested bamboo pole or stalk. An average order consists of at least five or six culms. That amount is enough to offset the shipping cost. You can expect to throw away at least a quarter of the stock you get for any of a number of reasons. If you're just trying this out, a good place to start would be a rod maker in your area. Beg, borrow or buy a nice 4 foot piece. That's enough cane for one fly rod, and assuming you only make a single tip, you'll have some leftovers for practice and mistakes.

These culms have check splits. I start a split on one end of the culm that eventually splits itself to the other end. This relieves pressure on the tube as it dries and reacts to temperature changes. If you don't do this, you'll get lots of little splits, which is bad as we'll see when we discuss flaming.



Analyzing the Physical Characteristics
Inspect the culm. Notice the different features. The culm should have a pale yellow color. This means it has been aged a while and dried out some. If there's any green tint to the cane, it's not ready to be used.

One obvious physical characteristic of the bamboo culm is the node. Nodes are the rings you see every foot or so along the length of the culm. It's apparent that the culm is a hollow tube, but you can't see through the tube. This is because of the nodes. I love nodes and I hate them. I love them because they add strength to the plant, allowing it to grow tall, straight, and strong. I hate them because they can cause many problems for the rod maker.

You'll notice that the exterior of the culm is smooth and kind of shiny. That material is called enamel. Think of it as the bamboo equivalent of tree bark. The enamel offers protection from parasites as well as creating a moisture seal for the plant. The enamel must be removed from the bamboo prior to becoming part of the blank. Preparing and removing the enamel are important steps, but for now, we're only interested in the visible condition of the enamel.

Larger culms are better: 2 1/2 to 3 inches in diameter is a good size. You can specify the size when you order. The larger cane is more expensive, but it's still the least expensive part of the finished fly rod. Get the best cane you can.

The fibers that make up the walls of the plant are thicker at the "trunk".



It's easy to spot the "bottom" of the culm, that is, the end of the culm that was closest to the ground as a growing plant. The nodes are closest together near the ground. It's easy to see the difference in the wall thickness at the top of the culm versus at the bottom. The overall tube diameter is fairly uniform throughout the culm, but the walls are usually two to three time as thick at the bottom. You must consider this difference with regard to planning the kind of rod you want to make. Generally, the top section is sufficient for small fly rods.

I often use the thickest bottom sections for bait casting rods--yes I do make those. The action of a good bamboo bait casting rod is similar to that of a broomstick, so you want to use the most dense cane. I've been told by the bass pro's that I make these rods for that their action is ideal for flipping large jigs. I'll have to take their word for it.

We've seen that the fibers near the outer wall or enamel are closely packed. Towards the inner wall, the fiber bundles no longer touch each other. They're separated by a soft cellulose. This material has no strength on its own and serves only to bind the fiber bundles together. The inner wall is made of a very soft material called "pith". Pith is so soft, you can scrape it with your thumbnail. The process of beveling and tapering the splines will eliminate most of the pith and wide areas of cellulose.



You may notice some writing etched into the enamel. You won't be able to make much sense of it unless you can read Cantonese. These marks are usually cut deeply into the culm. If the cuts are deep enough to allow you to see any lateral fibers underneath the enamel, the affected areas must be discarded. Rod makers call these "power fibers". They are the most dense right below the enamel. Power fibers give the bamboo fly rod its light and responsive action, so they need to remain in the rod, not on your shop floor or in the dirt somewhere in southern China.

There are a few more things to be aware of when evaluating a culm. Sometimes, especially near the ground, parasites enter the plant. The fibers are weakened at these "wormholes", rendering the area useless to the rod maker. A spline with a wormhole, hidden or not, will fail stress testing.



Leaf nodes are just that--a node that had a leaf growing out if it. Since there is such an uneven impression left by the leaf, the fibers surrounding it are useless to the rod maker. While leaves are essential to the plant, they're a problem for the rod maker. Thankfully, they're rare in most stock.




Study the cane that you have. Get to know it. You'll be spending lots of time with it before you can call it a fly rod. It's natural material, so it's unique. Bamboo is amazing stuff. It's so hard, that it'll dull a plane iron faster than concrete, yet delicate enough to baby your 7X tippet.