Fishing rod blanks are made of a carbon fibers composite or prepregs (=pre-impregnated) made by the chemical industry with a long, costly procedure. This industry is a high competitive business with huge earning potential (think alone at the aero-space and automobile industries which they source).

A composite is a material made of two or more different materials.

In a carbon composite the (monodirectional) carbon fibers are reinforced in a polymer matrix (e.g. polyester or epoxy).

But, first of all, is the raw material made out of carbon or graphite? Can we say graphite or carbon blanks?

Answer: actually we can say both. We can say carbon thinking of the atoms, the "material" at the base of the "stuff" we hold in our hands, and we can say graphite as well thinking of the molecule and thus the structure that the carbon atoms have.

So, in a carbon fiber composite, the raw material, the "carbon" is in its graphite form: hexagonal rings bond together in a ribbon structure (yes, not exactly in a plane like in the graphite of a pencil). The structure is very flexible, resistant to stretching, strong, and light.

The individual microscopic carbon fibers (thinner than hair) are then woven in a fabric (scrim). There are many kinds of fabrics tha you can make, depending on how the fibers are woven, their density, the direction, the space in-between, etc.

A fishing rod company which makes their own blanks must know which composite to order since the prepregs can differ in purpose, composition or fibre type, orientation, resin content, and weight per square metre.

Scrims: along with carbon fibers other fibers like glass-fibers, boron or ceramic are mixed together to form different layers: one of graphite+boron+ceramic, one of graphite+fibreglass and one of resin. Glass fibers are appropriate to use in the production of short, deep-sea rods where weight is not an issue but stiffnes is. And a fishing rod blank maker can often use three or four different prepregs for one rod, each for a different section of the rod.

The carbon composite material is very expensive, must be ordered often in large quantities and above all sometimes it must be quickly delivered and it should be stored in a freezer for it might downgrade if left at room temperature.

When it arrives, it is tough but "floppy" and soft. By heating it, the resin (e.g. epoxy) will stiffen and the pressure will make it more dense, harder.

TIP

Now, there are many types of carbon fibers: IM6, M8, M55, M40, M40J, M46J, T300, HR40, and more. Each have their own properties: which are the modulus and the strength. Good fishing rods have generally speaking a high modulus, a high strength, and intermediate percentage of fibres.

Modulus is the ratio (espressed in millions of psi, "pounds per square inch", a measure of a force on an area) between stiffness and weight of the graphite blank. The higher the modulus, the more energy the rod can store and release. The energy is a way of saying the speed and the power of the rod. Think of a swimmer on a diving board and try to imagine to variate the properties of the jumping board and you will see what it is. Some also simply by saying that modulus is resistance to flex and the higher the modulus the stiffer the rod. Beware, though, the higher the modulus, the more expensive is the blank and also more brittle the rod after an impact.

TIP So, for beginner rod builders, stay away from top modulus blanks and rather take a mid-range modulus.

You can judge a blank from some basic qualities:

How is the action of the rod, does it suit the purpose?
Does it cast well?
Does it feel light and well balanced?
Are the manufacturers known and reliable?


Tip You can buy black, uncouloured blanks or coloured ones. The latter are more difficult for a beginner rodmaker to use because if you make a mistake in the guide positioning or glue and you want to makes, you will get marks on the rod.

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Example of composite or prepregs suppliers which can be categorized by their size (I put a mark where I know the company is suitable for making rod building blanks;):

Large Prepregs suppliers:

Hexcel, USA

Cytecfiberite, USA

Toray, USA

Sk Chemicals, Korea

Small Prepregs suppliers:

Bryte, USA

HeatCon, USA

Advanced Composite Material,(resale of surplus materials), USA

From the page of fishing rod blanks continued explanation to the rod blanks supplier homepage

And if you want to see again the step-by-step pictures of a rod blank production click here

(Note: Kela Pro from where I took the first two pictures above, make windsurfing carbon components)