Pride goeth before a fall !

[Guest Mike Connor]

Thomas Young, an English Doctor and physicist, coined The term "Modulus", in the early 1800´s. The term is used as a constant in equations, as "Young´s Modulus", to calculate specific properties of certain materials.

 

In simple terms it may be seen as a description of a material´s property of resistance to bending.

 

Calculations using this, are essential for developing the fibres used in many modern composite constructions. The fibres, such as carbon fibre, Kevlar, fibre glass etc, provide the stiffness, at the same time reducing the weight which using other materials would involve, ("Standard", carbon fibre is about thirty % of the weight of aluminium , and roughly 250% stiffer ,)and the resins used hold the whole thing together.

 

So what does this have to do with fishing rods?, and why is the term "Elastic Modulus" so often bandied about?

 

It has to do with them, insofar as the term may be applied to the materials used in their construction. IM6 Graphite for instance, which you mentioned. IM6 has a modulus of about 35 million, although many manufacturers use fibres of much higher modulus. IM6 is actually only a trade name for Hercules fibre in any case.

 

However this may be, the fibres used in rod construction are only a part of the story. The taper, wall thickness, and of extreme importance, the resins used, are at least as important. In actual fact, of even greater importance than the modulus of the fibres used.

 

Rod designs vary considerably, and this may be controlled by any and all of the factors above. Using a suitable design, resins etc., practically any rod action may be obtained, anything from a floppy noodle, to as stiff as a poker. This really has little to do with the modulus of the fibres used, and is mainly the result of other design factors. Although higher modulus fibres may be used to produce stiffer lighter rods, they may also be used to produce noodles if desired. Lower modulus fibres may also be designed to produce fairly stiff rods, and in general, will be more robust than their high modulus counterparts, as the material used is less brittle to start with.

 

The modulus given by manufacturers only applies to the fibre used, and once this has been built into a composite, ( sometimes also rather inaccurately referred to as "laminates" ), it no longer applies, as the actual modulus of a finished rod is not dependent on the fibre used, but more on how it is used in the construction, wrapping, resin bonding, etc.

 

Various marketing departments have swooped on the term "modulus", and use it quite indiscriminately for all sorts of things, few of which have to do with the properties of finished fishing rods. It is basically hype.

 

It is not possible to compare fishing rods in any meaningful way by calculating their elastic modulus, and using the elastic modulus of the fibre used in their construction as a basis for such "calculations", is just nonsense, and will tell you nothing useful at all about the rods in question.

 

Attempting to build a composite rod blank at home, in the garage, workshop etc, using materials and tools available to even the "advanced" hobbyist, is a more or less impossible undertaking, and I would advise you to forget it. Simply wrapping fibre-glass matting, or even carbon fibre matting, assuming you might be able to obtain some, around a tapered mandrel, tunking it with activated resin, and allowing it to set, is extremely unlikely to result in a usable fishing rod, much less a good one.

 

To answer one of your original questions with regard to modulus, I know of no simple way to measure the modulus of fibres themselves. This stuff comes from the factory on rolls, as a form of "fabric", and the specifications are known. How one might go about measuring a piece of this in order to determine the elastic modulus of the fibres, I have no idea, although the manufacturers are obviously able to do so. Searching the web, or a library with good engineering literature should provide you with such information, assuming you still require it.

 

Various equations, calculations, recipes, specs etc. used when producing my blanks would do you no good at all, as they were material and circumstance dependent, and your chances of reproducing such are basically zero.

 

The quality of modern composite fishing rods is dictated primarily by the hardware and cosmetics. Practically any modern blank, even Far East cheapies, will make decent fishing rods if such materials are used. The price of finished rods is due to a very large number of factors. In some cases these prices may be inflated as you say, but once again, comparing raw material prices to finished rods is absolutely ridiculous. If this were true, then cane rods would cost next to nothing, as bamboo is a grass which grows like a weed, and basically costs nothing. This is patent nonsense of course.

 

There is considerable controversy about cheap rods vs. expensive rods etc. Some people maintaining that a cheap rod can not possibly be as good as an expensive one, merely because of its very cheapness. This is factually incorrect of course, certainly as far as composite rods are concerned, there are quite a number of very good cheap rods available. If you put good quality hardware and cosmetics on a "cheap" blank, then you no longer have a "cheap" rod.

Composite blanks are by their nature "cheap" products, as they may be mass reproduced easily and consistently at will, once the specifications are known. Pricing policies of various firms have little to do with the quality of their blanks, although of course may reflect good quality to some degree.

 

There is no way at present of mathematically comparing various rod blanks to one another in any meaningful or useful way, as most anglers choose their rods absolutely subjectively, based on how it "feels", how it "looks", price, manufacturers name, "modulus", etc etc. Quantifying such things is an impossibilty. Some manufacturers, and a number of other interested parties have been working on various systems of definition and comparison for some time, but as far as I am aware, nothing of general application has yet emerged.

 

If you think that a very expensive rod is better than some other less expensive tool, then you must perforce buy the expensive one. One thing is certain, it will not catch you any more fish than a cheapie. Although pride of ownership, "bragging value" etc may be greater.

 

When I built the blanks you mention, I had the assistance and knowledge of quite a few people behind me, and also access to factory capabilities, various types of fibre, and a whole range of specialist resins, which are impossible to obtain for a private individual under normal circumstances. Although I was originally obliged to meet a "price target" for the finished rods, price was not really actually an issue, as the final retail price of a fishing rod has little to do with its ex-factory cost.

 

Quite excellent rods which cost four dollars ex-factory in Korea, or Taiwan, are regularly sold in Europe and America under various brand names, for well in excess of two-hundred dollars. The final price has little to do with the cost of actually producing the rods, and certainly not with the raw material cost. Transport, advertising, several middle-men taking their profits, etc etc, all jack the price up.

 

This is also why comparing rods based on their retail prices is also absolutely senseless, as you have no way of knowing how this price was set. It may have absolutely nothing whatever to do with the quality of the rod.

 

Purely for informational purposes, the fibre used in my blanks was "standard" graphite, not IM6. Rods constructed of raw material which is less brittle to start with, are more robust, and should, theoretically at least, be less susceptible to damage, and also last a lot longer in normal use. This was one of my main aims.

 

Tools like rods, must not only be suitable for the application itself, fishing of course, but have a whole range of other properties which makes them more or less desirable for the purpose, and may be used to determine their "quality" more accurately than any mathematical equations relating to the stiffness or otherwise of materials used in their construction.

 

As far as I am aware, there are no absolutely conclusive studies about the useful working life of various composite rod-blanks, but modern resins, coupled with the manufacturing techniques now available should produce rods which will certainly last a very long time. There is some literature on the useful life of composites in aircraft manufacture, but this is highly technical, and not a great deal of use, as any conclusions drawn would have to be based on the use to which a material is put, and theoretical projections of such behaviour, with regard to composites built and used for other purposes would be suspect at least.

 

Apparently, bamboo is susceptible to "going floppy" after a while, presumably as the "springiness" of the power fibres lessens in use, to put it simply. This will also occur with other fibres, but will take much longer, and be less apparent. In fact it is unlilkely that a difference may be found at all in normal use, although it may be possible to measure one after a certain time in use. I am not aware of anyone having done this however. Although I have heard that this is often the case with bamboo, I have never actually attempted to measure or quantify it. Bamboo is interesting for a variety of reasons, and although I no longer have any bamboo rods, and the only ones I ever built were really quite awful, I still read a lot about it, and listen with interest to any comments etc from experts.

 

If you are absolutely bound and determined to produce a fishing rod from scratch, then your best bet is to build it from bamboo. Doing this is unlikely to be cheap, and there is no guarantee that you will even produce a half-way usable rod, but some people do manage this in a surprisingly short time. Some indeed managing to produce veritable masterpieces. There is a mass of information now available on building cane rods, and easily obtainable over the web.

 

Otherwise I would recommend you look around for suitable blanks, either composites, or split-cane, and build on these.

"Cheap" split-cane blanks should be avoided, as although bamboo itself is not particularly expensive in comparison to composites, blanks made from it are only as good as the skill and knowledge of the person or persons who built them, and the more expensive blanks are likely to be of considerably better quality for this quite simple reason.

 

I would have no qualms about using even the cheapest composite blanks to build on, as all I would have to lose would be the time involved and a few materials. Hardware etc may be used again, should the rod turn out to be useless, or not up to expectations in some way.

 

Hopefully all this is of some help to you. I decided to write such a long reply, as it was easier than answering the individual questions you posed.

 

Even though my name is listed at ********** and *******, and various other places, and I am prepared to answer general questions on fishing and tackle, as it is one of my primary interests, I am not an acknowledged or qualified expert on any of this material. I am also not a consulting agency, and I am unable to provide specific manufacturing details for various things.

 

I noticed that you also mailed me a couple of times last year on several subjects, and I sent fairly conprehensive replies. This information was obtained, in the main, from freely available sources, which is where I got most of it, over a period of time of course, and it should not be difficult for you to do the same. My time is valuable and limited, and you may appreciate that replies like this take longer than five minutes to compose.

 

Technical definitions may be quite easily obtained for all sorts of things nowadays, interpreting some of these is considerably more difficult, but if you wish to pursue some of these things, then you really have no choice but to apply yourself.

 

I am not a qualified mechanical engineer, in fact my main area of expertise is electronics, but I have studied the material involved here quite extensively, as a matter of interest, over some considerable time, probably more so than most pure hobbyists at least. Nothing I have written should be regarded as gospel, and other people may indeed have completely differing opinions on some things. Where facts are mentioned, they are correct as far as I was able to ascertain at the time of writing.

 

Also, none of the above should be regarded as an attempt to dissuade you from trying anything you like, I did so, even against quite considerable "expert" advice, and I am glad I did. I learned a lot, enjoyed myself, and the rods I produced were well received.

 

I am pleased you enjoyed my site, thank you for the kind words. None of this material, or similar stuff appears there, or ever will do so, mainly because it is not of really general interest. Most anglers could care less what their rods are made of, as long as they function properly,and perhaps have a lifetime guarantee !

 

Best wishes, regards and tight lines!

 

Mike Connor