By Roger McCourtney

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Chapter One - THE BLANK

For those that do not know, The Blank, is the main shaft of the rod without any fittings attached. It is quite obviously the most important component. In view of this, there is more to write with regard to the blank than any other component. For example, how blanks are made and from what materials. I will write about "Test Curves" and "Spines" in fact everything that I believe to be relevant.

For the purposes of the article I am assuming that the reader will be mainly interested in carbon fibre rods. If we go into the realms of Bamboo rod construction I will be at this keyboard for ever!

I will say here that I am a rod maker, I do not make rod blanks, however, my understanding of blank manufacturing is pretty good as I have been privileged to have visited Harrisons factory on a number of occasions. I will add that over the years Dr. Stephen Harrison has very kindly helped me in my business by imparting information not normally accessible to the general public and has helped me to develop "special" blanks.

The raw material from which carbon fibre is made from is a by-product of the petro-chemical industry called "Polyacrylonitrile". This material is put through a series of heat treatments and at a critical stage is suddenly starved of oxygen. The resulting material crystallizes and is then extruded into very fine fibres. Carbon Fibres in fact. There are many different types of fibres and I do confess to not knowing how these fibres differ nor in what way they affect the end product, it seems a closely guarded secret, but I will find out one day!

Generally speaking the average carbon fibre is approximately 16 times less than the diameter of a human hair.

The fibres are extruded to a length of 100 feet. On their own they are quite useless for blank making. To be usable the fibres are laid up into what the trade call "pre-preg". This is short for impregnated.

Pre-preg in laymans terms, is a loose laminate or cloth if you like consisting of a base of scrim. Scrim is usually a cross weave of very fine glass-fibre or woven carbon fibres. The purpose of this scrim is to enable the carbon fibres to lay longitudinally without falling apart. A resin system is then applied and then a layer of paper tape on top to hold everything together. The pre-preg is usually made in rolls 30 m x 1 m. The rolls are stored in refrigerators to prevent degradation.

There are numerous types of carbon fibre and not all types are suitable for the rod making industry. Much is made for the space and automotive industries. Generally speaking, and this IS a generalization, there are three types of carbon that is used in rod making, High Modulus, Intermediate Modulus and High Strength.

It is quite possible for a blank maker to use all three in one blank! Each type of carbon has its own properties that of course will have an effect on our finished blank.

So then onto how a blank is made. The operative in the factory will take the appropriate pre-preg and cut from it in most cases a long, thin, blunt ended elongated triangle using a template for accuracy. This will then be rolled around, lengthways, a chrome steel mandrel that has been ground to the taper required. This operation has been described as like rolling a giant cigarette! The whole thing is then further rolled in what looks like a giant trouser press to about 1tonne psi.

Once rolled the still soft malleable "blank" has to be held in place prior to firing. This is achieved by wrapping the whole thing in a cellophane type tape. A specially designed machine does this. The purpose of the tape is to not only hold everything together but also to form a shroud to prevent any resin to leak out whilst being fired.

The whole thing is then stood in an oven and the temperature is brought up to between 250 and 300 degrees centigrade. The whole heating process takes about 2 hours or so. During this heating process the resin system turns liquid and permeates through the fibres and scrim so that when it cools the resin,fibres and scrim have been "soaked" right through to the steel mandrel the cellophane tape keeping it from running away on the outside of the package. At some point however, most of the tape does burn away leaving the characteristic "spiral of ridges" present on the "un-ground" blank.

As it all cools down the resins hardens and we are left with a now hardened blank. The mandrel is the hydraulically withdrawn and there is now a carbon blank. At this stage the blank is, if required sent for "linishing". This process is basically where the blank is precision machine ground to remove the tape ridges. Then finally the blank is, as they call it at the factory, "painted" You might refer to this as varnishing!

Anyway a nice glossy finish is applied to the blank in the colour of your choice.

Now that is the blank making process revealed in a nut-shell. There is quite a lot more detail that I could reveal; however I feel sure that you will get the idea from this.

Obviously, one blank will not cover all fishing rod designs so choosing tapers and materials to get the required action have to be thought about. The fact is that choice is infinite. To arrive at the right blank the designer must consider firstly, the type of action that the finished rod must have. Is a fast action rod required, or will it be a through action rod. If for example a fast action rod is required the blank will be made with a fast taper. In other words the blank will appear to look more "needle" like, whereas the through action blank will have less of a steep taper, and of course there are many, many options between the two examples I have used.

Generally speaking, the faster action blanks are made from quite stiff, by stiff I mean "greater resistance to bending" Often referred to as High Modulus Graphite. Rods made from HMG are less forgiving when it comes to playing fish but are generally good casting rods, whereas Intermediate Modulus or the High Strength carbons feel better when playing fish and unless one is fishing at long range they will cast well and this type of blank is more "user-friendly" in my opinion.

Now it must not be assumed that all through action rods are "soft" action rods, that is simply not the case. Likewise a slim, light test curve , moderately fast taper rod, could be very useful indeed especially for touch legering, but a high test curve, fast taper rod will be brute, the sort of thing that long range carp fisherman might go for.

Then there is the question of length of blank to consider. It is a fact of physics, that the shorter the length of rod the more leverage (power) can be applied So for example a 10 foot rod of 1 ¼ LB t.c. is capable of applying greater leverage (power) than a 12-foot rod of equal t.c. e=f+d for those of the mathematical persuasion!

In chapter two, I will expand on rod "action". Hopefully impart information that might enable a potential buyer of a suitable Barbel rod or blank/kit to make a more informed choice.

The next chapter discusses rod action.