Rod blanks

Part Two

  • Montaje de una caña de grafito

  • How Rod Blanks Are Made Makes A Difference

    by Al Campbell

    You've decided on a rod weight, length and action. You might even know which company builds the graphite blank you want to use. Now it's time to learn how the rod blank is created. Although you won't be creating the blank yourself, if you know how a blank is created you might make a better choices when it comes to buying a rod blank. After all, it's the blank that does all the work in a finished rod.

    Most graphite used in rod construction is available on the market for any rod company to purchase. However, there are a few rod companies that use proprietary graphite (made exclusively for them) in their best rod blanks. Two companies that come to mind are Sage and G.Loomis. The main reason they order proprietary graphite is to control the modulus and quality of the graphite to the tightest tolerances. That doesn't mean the rest of the graphite is bad, but rather this graphite is more carefully created. Each step of the process is carefully controlled.

    End view of Graphite rod blank

    When graphite arrives at the rod company's receiving dock, it's on a big roll and looks a bit like a big roll of paper. On closer inspection, it looks like a dark fabric with paper on one side. The materials in this weave, the way it is woven and the resins on the back of it are all important to how the rod reacts to the casting stroke. If you lay the paper side down and take a real close look, you will begin to see the components of a rod blank. The layer closest to you, the one running lengthwise as the material comes off the roll, is the graphite that runs lengthwise through your rod blank. The modulus rating of your rod blank will be the modulus rating of the lengthwise graphite fibers you are looking at. If the graphite is a composite, another material (usually fiberglass) will be mixed with it.

    In boron rods, the material in this layer was a composite of boron and graphite. Recently Gatti introduced fly rods that are made of a ceramic and graphite composite. This might be the direction the better rod companies will move in the next few years.

    The next layer down is something called scrim. This will be some kind of fiber (fiberglass, graphite or a mix) that runs crosswise to the graphite or is woven, depending on the type of graphite sheet and the manufacturer. This layer keeps the linear graphite fibers from separating in the finished blank, thus keeping the walls of the blank from crushing.

    rod seam after resin

    The bottom layer (not counting the paper backing which is discarded after the graphite sheet is cut), is resins. The resins are the glue that holds everything together in the finished blank. The best manufacturers pay a lot of attention to the chemical makeup of the resins used in their blanks. If you get this step wrong, your rod will twist and break, especially if it has been allowed to get hot. No rod will withstand the heat of a car's back window for long without the resins becoming soft and starting to relax their hold on the graphite. Keep that little fact in mind the next time you park your car with a fly rod inside.

    The first thing that quality manufacturers do is check the graphite cloth for damage. No need to start with faulty components. If there is damage, the graphite is rejected and eventually destroyed or sold to one of the companies that doesn't care too much about the quality of the graphite they use in their rod blank

    Next, the graphite is cut into long, thin triangles. This is a critical step. If the graphite triangle is measured or cut wrong, it will greatly effect the performance of the rod blank. This graphite triangle (paper backing removed) is wrapped around a thin metal rod called a mandrel. The shape of the mandrel and the cut of the graphite triangle will determine the "action" of the finished rod blank. The better rod companies pay very close attention to these steps in the rod building process. Get these steps right, and you will likely have a great casting rod. Get them wrong, and you will be holding a 'dog' that won't cast a line right.

    After the graphite is wrapped or rolled around the mandrel (linear fibers running lengthwise, resins on the outside), cellophane is wrapped around the graphite to hold it together while it bakes. Cellophane won't melt, that's why they use it. The graphite covered mandrel is then placed in an oven and baked at closely monitored temperatures for an exact amount of time. As the rod blank bakes, the resins liquefy and penetrate throughout the graphite and scrim. If you ask a rod manufacturer how long they bake the blank and at what temperatures, you won't get an answer. They guard their secrets very closely.

    linear fibers

    Following baking, the blank is removed from the oven and cooled. The cellophane is removed and the rod blank is usually sanded to remove the ridges caused by the cellophane. Several manufacturers don't sand their blanks (Scott comes to mind), leaving the ridges caused by the cellophane on the finished product as a trademark. Most manufacturers sand the blanks, feeling the resin ridges serve no useful function and only add weight to the blank.

    The next step is to spray a clear, sometimes colored, coat of finish on the rod blank. Some manufacturers (G Loomis comes to mind here) omit this step opting to leave the blank dull and reduce the weight of the finish. While some people feel the finish protects the blank from impact fracture, a growing number of companies are skipping this step.

    Finally, the rod blank is trimmed and inspected. If the rod fails any step of the inspection, or if it fails the 'flex test', it is rejected. For those of you who are tempted to buy a 'blem', remember a blem is a blank that failed one or more steps of the inspection process. While most blems are merely cosmetic blems, it takes too much time and energy to build a rod to risk it all on a substandard blank. If the blank is made right, you will have a great rod to fish with. If not, you will be destined to fish with a 'clunker'.

    Quality components from a quality rod company are worth the investment. Your custom rod's performance depends on it. After all, you don't get Rolls Royce performance from a Yugo.

    Next week, the rest of the components that go into a custom fly rod. See ya then. ~ Al Campbell


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