Rod Making in the 21st century
By Roger McCourtney
Chapter Four - BLANK ALIGNMENT
What follows is my description of how to go about the work so that the end result is a fishing rod to be proud of. I have agonized about how to approach this subject as the whole subject of rod making can be written about in two ways. A stage by stage, "how two" type article, or a "general idea" type. I have decided to keep it as a "general idea" type as I am sure many readers will never attempt to make a rod but may still be interested in the process
Having taken delivery of the blank and assuming it is the right one and is not broken! (Yes it does happen). I will first wrap a small amount of masking tape to the bottom of the top joint and the same at the bottom of the butt section. I am assuming the blank is a two piece.
Holding the tip section very close to my nose, I will look along the blank. It pays dividends to point the section at a natural light source. I will be turning the blank so that the "natural" curve that is present on virtually every blank section is pointing upwards. I will also be looking very carefully for, with that curve uppermost, a straight plane. Some blanks are worse than others in this respect and sometimes this apparently simple process can take quite a while! A line is drawn on the tape that we fixed earlier, on the very top of the rod along what is now the blanks straight axis. I call these marks, line up marks! I then do the same with the butt section. From now on, the marked axis will be referred to as the top of the rod.
Pushing the two sections together using the line up marks, I will then look at the whole, now joined together blank. Hopefully, the blank will look straight. If it "kicks" off, then I will twist the butt section until the blank does look straight. In reality it may be an awful lot more difficult than I have made it sound.
At this point I will offer my opinion as to which joint system is the best. Is the over-lap, sometimes called over-fit, system or spigot best. Some say that the over-lap is stronger. My view is that so few rod actually "fail" these days with either system it doesn’t matter which type you choose. There are advantages as far as blank manufacture is concerned but again I would need a lot of space to explain why. Furthermore I would not wish anyone to develop hang-ups about ferrules, for that is what they are collectively called. Similarly, the various effects, or otherwise, that the two types of ferrule may have on the finished rod is not worth worrying about. It would be if we were designing a blank! But we have the blank in our hands and it will give us the action that we want, that’s why we ordered it in the first place!
But, he hasn’t mentioned locating the "spine" you would be rod maker’s shout, but I am going too!
The spine, or "spline" as the Americans call it, is the "stiff" side of the blank. Of the 360-degree total circumference around the blank, there is one point that appears more rigid, or stiff. This is the spine.
How is this "spine" found? The easiest way to do this is to hold the tip of the blank in the palm of your right hand, if right handed, whilst holding the section at about 45 degrees on a hard surface. With the left hand, press down, quite firmly, roughly in the middle of the section, so that it is well bent, then with the same hand, roll the blank across the hard surface, keeping the tip in your right palm. You will feel a point where the blank appears to jump or produce increased resistance against your right hand. That point is the spine. In case you want to rush off and check your rods, don’t bother, it doesn’t work with made up rods because the rings will affect the action too much!
How is the "spine" formed? It is created as a result of production deviations present in all blanks. Interestingly enough the "spine" is not consistent along one axis and migrates throughout the blank. What we find by our attempts to locate the spine is in fact an "average" of the many deviations that are inadvertently created during production. The main reason is that, when the carbon composite is wrapped around the mandrel, there is obviously a start and an end. The rolled composite has been likened to a Swiss roll in its make up!
To use the spine as a means to decide upon which axis to tie our rings is flawed. Firstly, it will been found that by rolling the blank against the hand, it is difficult to hold the blank on the spine axis, it wants to jump off all the time. In fact that axis is dynamically unstable. It may offer greater resistance to bending, but that does not make it stronger. What it will do, unless the pull of the line in the finished rod, is always exactly opposite (180 degrees) to the spine axis, and is kept that way, is to make the rod prone to twisting. Now who on earth can fish like that? Well there is one group of anglers that do fish like that, the deep-sea anglers that winch fish up from the deeps. For the rest of us, the angles of pull are all over the place.
To use the so- called spine as our datum point surely implies that the other 359 degrees of the blank is "weak". This simply is not the case, If it were then a huge amount of rods would fail and the rod making industry would quickly go bankrupt.
How do I align my rods then? Well in my view, customers in the main are oblivious of the spine thing but they do want a nice straight rod, and so do I.
There is a better way to determine upon which axis to tie the rings. This usually coincides with the natural curve mentioned before. It is called locating the "preferred plane of bend". I have previously mentioned how bamboo rod making has influenced modern day rod making, this is another example. Locating the PPB was and still is practiced by bamboo rod makers. Bamboo blanks do not have spines as such because the splitting and joining process is done on a hexagonal section blank and not on a round one. The PPB is found by holding the section absolutely upright on a hard surface and by pressing down with the hand, it will be noticed that the section will bend in a certain plane. Even if the section is rotated and the process carried out again, the section will bend in the same plane- the PPB. Well it so happens a carbon blank will do precisely the same thing! The rings can be tied on either the convex or concave side of the bend created by the pressing down process. The final choice is made by selecting the side where the natural curve bends upwards as previously mentioned which more often than not will be a straight plane!
I appreciate that this is a lot to take in, however it should demonstrate that to make a good rod is not quite as straight forward as it may appear, it is within the capabilities of a fairly practical person though.
In the next chapter, rod assembly proper will commence, at last!