Hello to all of you,
My name is Alexis, I am 19 years old and I work in a department store (Decathlon) in France.
I work in the fishing department and many customers often ask me very technical and thorough questions! I have a lot going on in my head and a lot of questions about fishing rods come to me and more particularly about blanks.  This is something that fascinates me from the outset, but many questions remain unanswered.  That is why I allow myself to ask my questions here ( with a bit of rough English and I apologize).  If anyone can tell me more, I will be delighted and I will thank you warmly.

Carbon differences hm, im, sm, delta ?

Interest in making a conical blank ?

What does PSI mean ?

What does 20T,30t, 40t mean ?

Is that the thickness of carbon has an ascendant on action and power?

Does the spacing and type of rings have an influence on the action, sensibilities and resonance ?

Why some blanks have 4-axis weavings or mini strips ?

Does painting and varnishing a blank pose a problem on its resonance, sensibilities and action ?

Does the fiber used in the butt of the blank have an influence on the action,
If so, can the action vary depending on the fiber use ( difference between carbon, kevlar and fiberglass ) ?

Changing the blank by shortening it or enlarging it could be a problem. Can it change its action ?

Why some blanks are smooth and others rough. As if they were small rings. ?

Among the multitudes of carbon type that exists, is that making a blank with several types of fiber can make it possible to obtain a single blank ?

Is an unequal shank better than an equal 2-strand shank ?

Many Thanks in advance.

King regards from France !

Alexis

Too many questions for me to handle, but one big aid to your knowledge of blanks, rods, and rod building would be for you to go the left margin and click on the "common cents info" link and go through it all until you feel comfortable with it. Keep in mind, that while CCS started as a fly blank/rod tool, it is applicable to any blank/rod. I provides an objective tool to compare the most important performance attributes of all blanks/rods. Much of the other stuff you are asking about have nothing to do with the performance of the rod. But CCS is very powerful in helping your understand and then utilize an objective tool in an environment that has few objective tools. Most of the descriptions sound like wine labels.

I will try to help to the best of my understanding. If any of it is incorrect I surely hope another member will set me straight,

1) HM = high modulus, IM = intermediate modulus, SM = standard modulus, and Delta, I'm not really sure. Modulus refers to a fibers resistance to bending. The higher the modulus, the greater its' resistance to bending.

2) I'm not sure I understand what you're asking. All fishing rod blanks are tapered, larger at the butt, smaller at the tip. Because of that, all rod blanks are conical in shape.

3) PSI - pounds per square inch. The PSI number is related to the strength of the graphite fibers used in building the rod. It's usually quoted in the strain rate of the graphite being used. But I don't understand the whole strain rate thing.

4) 20T, 30T, 40T is related to the graphite used in the rod. It's more or less a modulus number. 20 ton, 30 ton, 40 ton, etc ...

5) Rod blanks are tubes, as such there are certain aspects that are going to affect the strength of the tube. Wall thickness, diameter, and the material the tube is made of is going to affect power. Action is a result of all the previously mentioned factors, as well as the blank's taper.

6) Guide spacing has no affect on the action of the rod. The action is in the blank. Guide weight can and does affect the sensitivity of the rod, as well as the rod's resonance.

7) I don't know what you're asking.

8) Paint and varnish add weight to the blank. Therefore it will theoretically change the resonance and sensitivity from an identical blank with no finish. But unless there is a large amount of weight added by the finish, I seriously doubt any human could tell a difference. The weight of paint of finish will not affect the action of the blank. As before, action is in blank itself.

9) Yes, the material used in various parts of a rod blank influence its' strength in certain sections of the blank, as well as it's action.

10) If you use CCS measurements as your criteria, shortening a blank will change its' action. It will result in a slower action blank. If you take the length from the butt it will lessen the blanks' power. If you take it from the tip, it will increase the blanks' power. But shortening a blank, will always slow the blanks' action. CCS uses the entire length of the rod in its' measurements. RDA is another way of measuring a rod blanks characteristics. I believe but not sure, that RDA uses the portion of the rod blank from the reel seat, to the tip for its' measurements.

11) Blanks that are smooth have been sanded smooth. Blanks with a rough finish have not been sanded. NFC X ray, NFC Delta, and Point Blank rod blanks are examples of blanks that are not sanded at the factory. Or at least not sanded completely smooth.

12) From my understanding pretty much all rod blanks use different modulus graphite fibers in different parts of the blank. Different manufacturers use different names for it. I believe Rainshadow calls it DMP, dynamic modulus positioning.

13) I don't know what you're asking.

Gave it a shot. Hope it helps, and I also hope that other members will chime in and tell me if what I have posted is incorrect. One can never stop learning.



Edited 1 time(s). Last edit at 10/30/2020 08:22PM by David Baylor.

The "RDA" is just a knock off of the CCS Big Picture where only a portion of the rod blank is measured. If you are not measuring the same portion-length as someone else is, then the results are not relative.

It should also be mentioned that the CCS does not measure fly rods, nor casting or spinning rods for that matter. It measures action, power and speed and any rod blank (or even a piece of PVC pipe) that has these characteristics can be objectively and relatively measured with it.


..................

the only Delta that comes to mine is from NFC and it's Delta blanks which are a composite of sm graphite and a unique fiberglass.

The weaving or mini strips, as you say, are the top layer of graphite fabric used on that blank. Most blanks are created using layers of fabric with the fibers oriented in different directions and sometimes woven. On the pattern you are referencing, the woven fabrics can help with hoop strength but also provide a unique decorative element.

Most multi piece blanks are created with the sections being equal length in order to make the easy to transport. I don’t believe that having unequal section lengths provides any particular advantage other than serving move the point of higher strain that occurs at the ferrule to a point deeper in the blank.

Dave gave you some great info but I’ll tie one theme together. The modulus rating, ton rating, and PSI ratings are all tied to the modulus of elasticity and come from manufacturers quoting different parameters that are related to it. Higher is better when it comes to building a lighter, more responsive blank.

My last bit of advice, hang around here for a while and learn to build some rods and you can start giving customers some insight from the perspective of a rod builder. It’s a very satisfying endeavor.

I will add that though carbon fiber is stronger per unit weight, it is also more brittle, and more easily damaged than is fiberglass. Manufacturers like CTS, Epic, Nfc, and Winston add other materials to help strengthen the blanks, and make them their blanks both stronger (more lifting power), and more resistant to brittle fracture Fast action means that a blank is highly flexible only about a third of the way from the rod tip to the but. Moderat-fast bends deeper along the blank. Slow means that the rod bends deeply toom the tip, to the butt. Slower actions tend to keep light lines from breaking as easily when a fish is hooked, and lays down dry flies and lures more delicately on the water. Fast actions give greater casing power, and are better for throwing heavier lures, streamers, and flies. Ice rods are often made of solid fiberglass blanks, as they are very tough.

Go to websites of NFC, Epic, CTS, and others. Each will of course tell you why their blanks are best. But you can also get some good info about the construction of their blans.There are so many good rod blank manufacturers around. It's easy to find them, and get some good info. Also, look at independant reviews to see what others say.

Tightlines and frsky fish

RJF

Carbon Fiber isn't at all brittle. That's a common misnomer about it. It simply doesn't take much of it to build a rod with the same stiffness as those rods made with lower modulus fibers, therefore the structure isn't as substantial and is not able to take the bumps and bangs that larger diameter, heavier walled rods can.

.............

Bless those who responded, I just sat here with my mouth hanging open. Happy Halloween.

Hello has all,
Thank you very much for your response.
If I shorten a blank by several centimetres, can this change its action?
Thank you !
Alexis

Technically, yes. As a centimeter is basically 4/10ths of an inch, shortening a blank by a few centimeters won't make much of a difference in action or even power. With a trim that small, I'd be very surprised if you could tell any difference at all.

I've only cut down two of the blanks for the rods I've built. I took 6 inches off the butt of both of the blanks I used. While I didn't perform CCS tests on the blanks prior to trimming them. I did flex them, noting how they felt power wise, and where on the blank the initial flex occurred. After trimming them they felt less powerful (one of them drastically so) and it definitely changed where on the blank the initial flex occurred.

Trimming any blank will affect its action. The result is always a slower action rod. Because action is tied to the length of the rod, both in the traditional sense of the percentage of length of the blank that initially flexes and in the CCS measurements in which action angle is determined by vertically deflecting the tip a prescribed percentage of the overall length, you are altering where the flex point is in relation to the length of the blank.

Trimming from the tip will result in raising the lower limit of the casting weight range by removing the most flexible portion of the rod, but not drastically alter the lifting power. By removing the most flexible part of the rod, the action slows (most easily described) by reducing the CCS action angle.

Trimming from the butt will decrease the lifting power of the rod. The action slows (most easily described) by moving the butt of the rod closer to the initial flex point of the rod.

Small trims of a few cm or in from the butt of the rod have marginal effects on the rod and can be used to tune the length of a blank to suit an angler's preferences. Trimming the same amount from the tip can drastically alter a rod, just as when you break the tip top off of a rod, it's never the same afterwards. I don't perform tip trims, unless I have a specific need to. When trimming from the tip, it's best to go in very small increments until you get the tip flex you are looking for, as you can't put material back. In the case of a butt trim, if you go too far, you can at least extend the handle to compensate for the error.