There were some questions here a week or so ago about the relative weight of handle materials, woven graphite, Texalium and cork. Yesterday I weighed a 1 foot by 1 inch piece of each.
Woven graphite....38.1 grams
Texalium...............37.3 grams
Cork......................32.9 grams

However, the woven graphite and the Texalium require some sort of spacers. The light weight foam spacers weigh almost 2 grams each so 3, 4, or 5 spacers increase the weight of the woven graphite and Texalium another 6 to 10 grams or more with heavier spacers. Plus the cork had a 1/4 inch internal hole. If this is reamed out to say 3/8 to 1/2 inch that will reduce the weight of the cork by roughly 7 to 10 grams. So the total weight of one foot each installed, not including the epoxy that will be roughly the same for each, is about:
Woven graphite....44 grams
Texalium...............43 grams
Cork......................26 grams



Edited 1 time(s). Last edit at 04/13/2006 08:08AM by Emory Harry.

This is interesting. I wouldn't have known cork to be lighter if you hadn't tried it. But I wonder about the difference between the chambers created by the tubing. Won't those create more sensitivity as the vibrations modify or amplify in the hollow area? I would have to think that cork being a little bit spongy would absorb those vibrations.

Did you weigh the epoxy to fit the arbors for the tubing, or the epoxy to glue the cork together & to the blank? How about the Tru Oil or Cork Seal?

Rob,
The vibrations can't be amplified and sensitivity can't be enhanced.
However, some materials transmit the existing vibrations better then
others.

The softer the material the less vibrations get transmitted. IMHO

Raymond Adams
Eventually, all things merge, and a river runs through it..

"So the total weight of one foot each installed, not including the epoxy that will be roughly the same for each, is about:..."

I assume that Emory did weigh the cork with the rings glued up. He can elaborate. Cork is a rather interesting material and one that in some ways has yet to be equaled by synthetic materials.

On the hollow cavitiy or chamber formed by the tubing, no, they will not increase sensitivity through any amplification of vibration input. The amount of input is too small and the hollow cavity far too small, for any such amplification to take place in any amount that would be noticeable to the human hand.. It just doesn't happen and scientific tests prove it. More on this in an upcoming issue in RodMaker.

Beyond any of this, each material still has its place in handle assemblies. It really comes down to what attributes you're after. It might be less weight, it might be purely comfort, it might be asthetics, it might be durability, etc., or some combinatin of these and others. So none are "better" than another, perhaps just better for your particular requirement at the time.

..........

Emory,
I was the one who made the original post and I appreciate your results.
I had come to essentially the same conclusion with respect to weights.
I also weighed the various components of the handles and agree on the total weight.

I think that many folks get too hung up on weight - handles, guides etc.

Folks go out and spend $$$ for a blank that is 1/2 oz lighter than a different blank.
Then they go out and spend $$$$$$$ for guides that save a total of 1/4 oz for many more $$$$ than guides that are 1/4 oz heavier.

When the beautiful rod is all finished, they go out and spend $$$$ and put on a rell that weighs 11 ozs on a 3 oz rod - that could have been have the price if it would have been 4 ozs.

Does the 14 oz combo fish any better than the 15 oz combo ? I wonder.

Take care
Roger

Roger, you silly goose. Why would you put such a clunker of a reel on such a light rod? 11oz reels - PFFT!

[japantackle.com]
[japantackle.com]

You NEED reels which weigh less than 6oz, or all the weight savigns people are putting onto their rods aren't fuly maximized, thus a total waste. lol.

Tom is correct. The weight of the epoxy is roughly the same for all three materials so it drops out of the calculation.
Raymond is also right about some materials transmitting vibrations better than others.
The impedance that a vibration sees traveling through a material is the square root of the mass density of the material times the modulus of elasticity of the material.
As far as a cavity amplifying vibrations is concerned, this is totally bogus for several reasons.
1. If you assume that the frequency of a fish bite is on the order of 1/ sec. to 10/ sec. and the vibration will travel at about 1000 ft/sec. in air, the size of the cavity would have to be from 100 ft. to 1000 ft. long to be one wave length and resonate at those frequencies. Think about a pipe organ that uses pipes that are many feet long to produce frequencies that are a couple of orders of magnitude higher in frequency, shorter wavelengths, than the frequency of a fish biting.
2. Any resonant cavity has a property called Q. What it says is that the wider the range of frequencies that a cavity tries to pass the less efficient it will be. The above assumption of a fish biting over a range of frequencies 1/sec. to 10/sec. would result in a very inefficient cavity. Using the same example as above, the pipes in a pipe organ have very high Q. In fact so high that they will only oscillate at a single frequency or note.
3. A fish biting gently, where rod sensitivity is important, is introducing very, very little energy into the rod. Much less energy than it would take to make any cavity resonate at those frequencies.

You will SEE activity in the line before you FEEL it with the rod.

Raymond Adams
Eventually, all things merge, and a river runs through it..

Roger,
I do not think that I agree with your conclusion about weight if you are talking about rods that will be used to cast as opposed to boat rods. I think that weight is extremely important and it is the one thing that a custom rod builder has control over. The added weight at the butt end of the rod is not as important because the effect of added weight increases logarithmically as you get closer and closer to the tip of the rod. Experiments have shown that one extra guide on a rod of medium power or using guides that are one size larger can result in lowering the rods performance as measured by the resonant frequency by close to 10%.
The problem is not actually the weight but the mass and the inertia that the mass creates. Try this to prove it to yourself. Take your favorite casting rod and shake it to get a feel for it. Now tape an extra guide on at the butt of the rod and shake it again. You will probably not even be able to feel the effect of the added weight. But now tape that same extra guide on the rod near the tip of the rod and shake it again. Now the effect of the added weight of an extra guide should be very obvious and the harder you shake the rod, the faster the tip moves, the more obvious it will be.
Raymond,
The velocity of the vibrations through the materials that rods are made from is so high that you should feel it in the handle at almost the same instant that you see it in the line. But that is not to say that sometimes you cannot see line movement when you do not feel anything.

Emory,
what diameter was the cork reamed to?

Regards,
Todd Vivian
Mud Hole Custom Tackle

todd@mudhole.com

Todd,
The initial weight is of the cork with a 1/4 inch hole before it was reamed. I just estimated that the cork weight would be reduced by 7 or 8 grams when reamed out 3/8 to 1/2 inch. Maybe I should ream out a foot of cork to 1/2 inch to see what the actual reduction in weight is. I did not do it because the size of the internal hole will vay with each blank.

Emory,
I know on our models that we build with the carbon tubing most weigh less than the cork. I suspect now that the ones that do weigh less are the smaller diameter blanks.

Todd

Regards,
Todd Vivian
Mud Hole Custom Tackle

todd@mudhole.com

Even with the small, original 1/4 inch bore, the cork cylinder is likely to be lighter than either of the tubes and their arbors.

But as mentioned previously, where the weight is located is just as important as how much weight we're talking about. I'm not sure that using tubing material, even though it's heavier than a similar cork cylinder, is necessarily detrimental considering that we're adding that weight at the butt of the rod. In fact, in some cases that slight additional weight might help balance the rod better. I'm all for building rods that weigh less, but within reason. Depending on what you need your handle to do for you, something that adds only a marginal amount of extra weight isn't likely to penalize you in other ways very much.

Rich Forhan has an upcoming article in RodMaker on some new ideas on how to maintain good sensitivity regardless of what you use as your handle material. As usual, he has taken a very practical approach.

Sensitivity is an oft discussed topic, but in many cases, it's not what it's cracked up to be. Lighter for the same stiffness (and similar weight distribution) usually means the rod will be more sensitive, but most strikes probably aren't detected by feel. I'm not saying sensitivity in the rod itself isn't important, just that we have to consider everything the rod must do and build it accordingly.

...........

I should probably make one additional point in response to Raymonds post. The amplitude of the vibrations will not really vary based upon how hard or soft a material is. As the vibration travels through one material into another it will increase or decrease in amplitude based upon the mass density and the modulus of elasticity. This is another reason why a cavity in a handle will not work. As a vibration travels down a rod and reaches the cavity it will encounter the air in the cavity which has much lower mass density and modulus which means the amplitude of the vibration in the air will drop dramatically. The remainder of the energy, most of the energy, will be reflected back up the rod toward the tip of the rod.

Tom,
I would sure agree that a small additional weight toward the butt of a rod is not going to have a large affect on rod performance. And the affect of the added weight of the Texalium or woven graphite is usually going to be swamped by the weight of the reel that is attached to the rod farther up the rod. These handle materials are probably going to be a little more sensitive and a lot more durable than cork. However, if the rod is going to be used to cast with then added weight is extremely important as it is added closer and closer to the tip. Using efficiency as a measure of sensitivity is fine as long as we realize that stiffness is a curve, a rod gets stiffer and stiffer as we apply more and more load, (rod power is a number but stiffness is a curve) and that the total weight is not nearly as important as the weight distribution or actually the distribution of the mass.
Plus weight is all that a custom rod builder can control. Everything that the custom rod builder does adds weight so I think that the custom rod builder should keep this added weight foremost in his considerations.

It's been a number of years since physics and engineering mechanics, but I'm thinking the discussion re: vibrations propagating (or not) through air gaps in a rod handle is appropriate only if air is the only thing "connecting" the handle to the blank. The minute that a more solid connecting material, such as tape or graphite arbor, is introduced, its properties are going to dominate the transfer of vibration from the blank to the handle material; the air gap becomes inconsequential.

Bilgee

Right on target, Bill. And Rich will be discussing this in his approach to maintaining sensitivity in our rod handle assemblies.

..........

Bil,
You are absolutely right. I have made the problem fairly simple when in fact it is very complex. As you suggest the majority of the vibration goes all of the way down the blank under the handle to the end of the blank and then reflects back up the blank. Only part of the vibration is transmitted through the handle material to the surface. But then a portion of the reflection also gets transmitted through to the handle . Each time the vibration sees a discontinuity, a change in the mass density or modulus, whether it is graphite to cork or air or tape or whatever a portion will be transmitted and a portion will be reflected. But your point is well made. The difference in the mass density and modulus between the graphite and air is the largest discontinuity so little of the vibration is transferred from the graphite of the blank to the air and then on to the woven graphite or Texalium. Most of the vibration that is felt at the surface of the handle will have come through the shims.
There are also the issues that I am not really on top of like how much of the vibration is dispersed, how much is absorbed and the phase reversal at each discontinuity adding to and subtracting from the primary wave, whether the waves are transverse waves or not, and no doubt more issues that I don't know a darn thing about.
It has been a lot of years for me as well. I guess we should probably try to find a good physics book that does a good job of covering vibration.

thanks for all of the thoughts and comments.
Over the years, I have done quite a bit of experimenting - with a simle "feel" the tip -- type testing of the rods ability to transfer vibrations.

I have used different kinds of arbors. Used tape, graphite cork, and just shims to allow for air transfer.
From a purely experimental feel - I have found that if the handle is 100% cork - and the entire hand rests on the cork - nothing on the blank, no fingers on the blank - that the maximum feel is obtained.
I have foun d that not completely filling the cavity with an arbor - decreases feel. Hence the thought posted above that the air reflects the vibration rather than tranferring the vibration.
I have found that the tape arbor dampens vibrations more than any other solid arbor. Possibly this is part of the post mentioned above about material differences, or the fact that the tape has a fair amount of trapped air in the tape.
The carbon arbors are quite good about transferring vibration. However, the best has been to use a full piece of cork with no arbor - or if using a reel seat to use a "cork" arbor.
I have also done experiments where I varied the length of the fore grip - so that a person would only grasp the fore grip (cork) or a shorter fore grip - so that a persons finger naturally rested on the blank. I have consistently found that better feel for what is going on at the tip - was obtained by using a full cork fore grip - with no fingers on the blank.

Thanks again.
Roger