Good evenin' folks,

I may be about to open a SERIOUS can of worms with this thread, but what the heck.....here goes anyway. Being in the blank distribution business, I get asked A LOT about the construction and makeup of the various graphite rod blanks that I sell. And, I have to say that whenever somebody asks me about modulus I just cringe! Here is why; It seems that about 90% of the folks that email me want to know what the modulus is of the blank(s) they are considering buying. When I ask "Why do you want to know that" they can't really give me an answer....they're just convinced that higher the IM rating is better. Here is how the conversation usually evolves:

Mr. Customer: What modulus is that blank made from?

Andy: Well, if you must know, it's about 40million Msi

Mr. Customer: What does that mean?

Andy: Well, it means the blank is made from the material you have come to know and love as IM6

Mr. Customer: Oh, that's too antiquated...I only fish with IM7 and higher.

Andy: Really? Did you know that the difference between IM6 and IM7 is not the modulus it's the tensile strength?

Mr. Customer: Really?

Andy: Yeah REALLY!

Mr. Customer: Eh Hhhmmm....erreer, uh, oh....well uh....well Bass Pro Shops says...

Andy: Forget Bass Pro shops...let's look at the numbers (at this point Andy whips out his trusty data chart that illustrates the differences between the different fibers that actually have IM designations). Here take a look at this. This comes from a chart put together by the folks at Hexcel (http://www.advancedcomposites.com/technology.htm)
The number on the far right is the modulus of the fiber, and the number in the middle is the elongation to failure or stretch.

Hexcel IM4 600 40
Hexcel IM6 760 40
Hexcel IM7 780 40
Hexcel IM8 790 44
Hexcel IM9 920 42

Mr. Customer: You Mean all this time I thought I was getting a higher modulus fiber with the higher IM rating, when what I was really getting is a fiber that stretches more?

Andy: Well, in some cases you are, and in some cases you arent. The fact is though that the difference between IM6 and IM7 is nothing in terms of modulus, and compared to IM8 it's only slightly higher. Wow...look at that IM9 actually has a lower modulus than IM8...go figure Now, many companies are using fibers with a much higher modulus, like 57 and even higher, however these fibers don't necessarily use the IM ratings. So, whenever you see a fiber with an IM rating...BUYER BEWARE! THE HIGHER THE IM RATING, DOES NOT NECESSARILY MEAN THE HIGHER THE MODULUS!!!

The point is this folks...just because you have a blank made from a high modulus fiber, doesn't means it's a good rod! And vice versa, just because you have a blank with a low modulus...even the original fiber blanks were made with (33 million) doesn't mean it's a bad or outdated rod. It's all about what the designer does with it.

I know there are some of you that may already know this, but judging from the amount of calls I get on a daily basis from folks who ONLY want IM7 or IM8, but can't really tell you why, I have to believe they don't really know what they are talking about at all. They've just been sucked into the marketing machine that leads people to believe that the higher the IM rating, the lighter and more sensetive the material, which is not always the case.
Be forewarned that there is A LOT more to graphite blank construction, performance, quality, sensetivity, weight etc... than just what modulus the fiber is. There are lots of other variables like flag patterns, and wall thickness, and resin systems, and mandrel design....It's all about the talent of the designer, and what he is able to do in terms of the sum of those variables...not just the friggin modulus!

Whewww...ok I feel better now...

My aforementioned explanation of modulus and IM ratings is by no means meant to be anything more than a brief primer for the folks who didn't realize what the differences with the IM ratings were. I hope this clears things up a bit, and I hope that some of you will chime in on this as well. Oh, here is a link to the Hexcel page for those of you who want to investigate the matter further. Do a search for IM6 and you'll get some interesting info. (if you're into that kind of techie junk).

[www.hexcel.com]

[www.advancedcomposites.com]

Now, this gives you some ammunition...next time you stroll into BassPro, and some yahoo tries to sell you a rod based on it's IM rating, ask him to explain to you why the higher IM ratings are better. When he replies by sayin' that the higher the IM rating means more sensetivity, less weight etc....just tell him that you have a blank at home made from IM2000, and see what he says.

Regards,

Andy Dear
Lamar Manf.

Another interesting point to note is shown in the Hexcel data sheet for IM6.
[www.hexcel.com]

While 40 MSI is the number for the modulus listed under "Typical Fiber Properties," Hexcel also lists the "Typical Epoxy Composite Properties" -- where the modulus drops to 23 MSI. I think that is another huge factor that frequently goes overlooked. Also, I'd guess the typical fishing rod blank doesn't even get that high of a modulus because of less than perfect fiber orientation.

Thanks for the websites Andy!

If anyone else out there is interested in more on composites there is a great magazine called High-Performace Composites that you can get a free subscription to from [www.compositesworld.com].


Mark

Ya'll ain't got any of them purty IM 10's?

Gerald Mc

I will ask the next Redfish I encounter which Modulus does he prefer to battle!

Post well done - thanks! Will print and post in shop!

Gon Fish

Great Post and long overdue!!! Thanks, Andy! See ya in Charlotte

Mike

hey andy thanks for typing this all in now i can print it out blow it up ad a few of my words and stick it on the rod shop door.. i couldent tell you the amount of customers that have asked these ???

Preying on the ignorance of the consumer esp. with numerical data has always been a great marketing ploy. I build astronomical telescopes and when someone looks through them they will say wow that's a powerful scope and I will say yes 40x. And they say how come the little camera store scopes are 600x. Or someone will come in the yard and see a tractor with 7 ft tires and say wow that must be a powerful tractor and I will say yes 60 hp and they will say how come my little Honda civic has 150hp...

Andy thanks for the burnt cork... real nice stuff ...Bob.

sounds like another great article, for the library?

Andy,

Thanks for the recent e-mail and this post. You ought to submit and article to Tom publication. You help clarify many questions I had.

Ed Smith

Bless you for that Andy!

Samuel Johnson noted that "Patriotism is the last refuge of a scoundrel." But those were simpler times. Madison Avenue has opened up vast new galaxies of gobbledygook and flim flam. Sad that techo-babble is so prevalent in many of the pastimes and recreation that we men use to while away the hours. I'm sure someone could convince me it all boils down to some sort of urination competition.

Now, can you fix me up with a blank that has an IM I can turn up to "11"?

John,
Is that a Spinal Tap refernece? I swear if it is.....you and I are gonna get along rrreeaalllllyyyy well!

Andy

No, sorry, that's a Nigel Tufnel reference.

C'mon man, I get along with everybody! Seriously though, I loved your rantlet. Doesn't exactly bite the hand that feeds, but still I recognize the frustrations of a craftsman trying to be courteous, informative and helpful with the uninitiated. Not easy to do through clenched teeth, I might add.

The computer industry has been through the same thing with the "megahertz wars." Macs running at only half the "megs' are generally twice as fast as Wintel boxes advertised as having higher meg processors. But what they do not tell you is that the Mac has a more efficient processor running at 64 bits while Windoze runs at only 32 bits. But, Windoze gets the sales because all the consumer looks at is the higher meg numbers. You can put money into your machine or into your advertising and many companies have figured out that it is more profitable to put the money into advertising.

Nice to see the info but you can't really fight this type thing whether you are talking about computers or fishing rods. It is called marketing. It is going to happen whether you are talking modulus, megahertz or cubic inches.

Sounds like Andy had a tough week; it was overdue to bring up, that's a no-doubter.
Don't ya just hate those urination battles, though!! Nothing like arguing with a customer who's been brainwashed by advertising.

Putter
Williston, ND



Edited 1 time(s). Last edit at 07/29/2005 12:47AM by Randy Parpart (Putter).

Very informitive post Andy!
I have only this year started to understand rod blank construction along
with the terms and definitions. I , at one time was one of those fisherman
remarked about. ( how embarrassing! )
Question: how does one messure "strain rate. "
Does not "modulas" and "strain rate" go hand in hand?

I for one, am not to influenced by the numbers touted by blank makers as I still don't understand them completly.
I very well understand "marketing mumbo-jumbo" and frankly only know what I "feel" and "see" for myself when on the water!

Experience is the best teacher always but I would like to uderstand the technical aspects as well.

Thanks again all who responded ! Keep it up Andy!!

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

Andy makes some good points and I agree that the tech data is often misused and misunderstood from a marketing perspective. I think that's the reason some of the manufacturers have gone away from publishing the modulus, esp. since it's only part of the performance equation and not always well understood by many as is pointed out. One small correction though, the number in the middle of the table is the strength, which is given by the peak stress that the material will bear and is given in units of pressure (Force/area). This is different than the elongation, or strain to break which represents the how much the material stretches before it breaks. Although dimensionless, elongation to break is typically represented as a % change. Carbon fiber elongations are in the range of 2% or less which is indicative of fairly brittle materials.

Raymond, the way some rod manufacturers use the term "strain rate" is a bit of a misnomer. The measurement of the material strength, and the strain to break is typically done on a machine called a load frame. The sample is clamped between two grips and is pulled apart at a programmed rate.... 1inch/min. etc.... (strain rate) until it fails. A load cell records the force and the sample cross-section is input in order to calculate the stress. A strain gauge is used to measure the sample elongation or strain rating.

Here's a link with a pic of a fixture:

[www.mts.com]

As the Intermediate Modulus (IM) materials go, the main point of the post is well taken. Generally, the mechanical properties of all the IM the fibers are not largely different. The IM7 fibers have a surface treatment which improves the shear strength and the IM9 fiber is measurably stronger that the other IMs. Someone was joking about the IM10, but Hexcel doesn’t make an IM10 so I suspect it's one manufactures marketing play on the acronym.

mark

Thanks for correcting that Mark,
I was reading the part about elongation to failure and had that on the brain as I was writing., and accidentally substituted that for strength. You're correct about the manufacturers not boasting modulus as much as they used to, but the big name brands still do on their house brands like Bass Pro, Cabelas, Berkley, ABU and others. The damage has pretty much been done though, and that's evident by the number of emails and phone calls I have to field everyday from folks boasting modulus facts and figures, about the blanks I CARRY, which turn out to be myths. One of the things I have tried to do is become really knowledgeable about the products I carry. I think most of my vendors will tell you I can be a real pain in the butt, bombarding them with questions about the products they sell. @#$%& I am surprised Sharon at AllStar hasn't just set me up an office with a nameplate on the door that says "ANDY DEAR PAIN IN THE BUTT DISTRIBUTOR" But you know what? I figur that I owe it to you guys as my clients to be as knowledgeable as possible about the products I carry. I don't know why many of the other distributors out there have not confronted this issue
I'll be honest about it. I think a lot of it boils down to ego. I think we all have a need to be knowledgeable, and even more importantly respected amongst our peers about whatever craft or sport we may be involved in. I suppose that's human nature, however some people take it to the extreme without doing the necessary investigating to make sure their facts are correct. Thye just spout off about whatever...in this case modulus either thinking they are really correct, or not knowing for sure if they are correct, and hoping that whover their conversing with won't know the difference!
There are a few local rodbuilder's who like to brag about how long they've been building rods, and how much they know about the craft...one even refers to himself as a "Master Rodmaker". He tried to convince me one time that he formulated all the guide spacings for G Loomis rods (this was done in front of about 6 customers in his retail outlet....in order to establish who was the stud duck in the store I am sure). I just politely smiled and said "Gee...you must be a really good rodbuilder". A few months later, I mentioned it to Gary (Loomis), he looked at me and said...I don't anybody to calculate something as simple as guide spacing for me...and besides, I don't even know who that person is! We both had a good laugh about it, but it goes to show how far some folks will go to elevate themselves in front of a group of their peers.
Just today, I had a Brand new greenhorn rodbuilder come over to my shop...he's building his first rod, and he's so excited he's about to pee in his pants! I swear the first thing he asks me is "what modulus is this blank?" I about swatted him in the head with it! I am sure that he had no idea what modulus actually means to a rodmaker and or a fishermen. When he showed me the rod he had been fishing with, the first thing he pointed out was the IM7 logo next to the Berkley logo.
Anyway, I am glad my original point was so well taken. It really was meant to help anyone who is interested in seperating fact from fiction. As for a magazine article, I am nowhere near educated enough to write a technical piece like that. I'd like to see someone like Stephen Pratt from CTS take a stab at writing something like that.....He is an amazingly knowledgeable and talented guy.

Regards,

Andy Dear

Many builders have gotten the idea that the higher the modulus is, the higher the quality must be. Obviously, the modulus of the fiber has little if anything to do with quality, but that's where vague advertising and marketing have gotten us.

Builders should also realize that nomenclature such as "IM6" and "IM7" aren't ratings - they're simply fiber designations. Big difference.

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

I woiuld be careful that we do not throw the baby out with the water here. Granted the modulus numbers that are quoted are only for the fibers not the overall blank and because we normally do not know anything about the amount of resin, scrim and finish used we do not know what the modulus of the blank itself is.
However, the modulus of elasticity is very important. It should not be reduced to something of minor importance to rod builders just because some manufacturers use the term in misleading ways in their advertising. The reason that graphite is the best material that is presently available for rods is primarily because it has a high modulus of elasticity, low weight and reasonably high tensile strength.

I would agree that the highest modulus graphite is not always the best choice for a rod. Very often a lower modulus is a better choice but for a reason that has not been mentioned above and that is as the modulus of elasticity increases the strain energy decreases. Strain energy can be thought of as toughness and is different than tensile strength. It is actually the area under the stress/strain curve while tensile strength is a point on this curve. But as the modulus increases the strain energy of the material decreases resulting in a blank that is more fragile. The higher the modulus of elasticity the more fragile a blank will be. The blank designer can offset this somewhat with the design, mainly with a smaller diameter and thicker walls, but this approach is very limited because smaller diameter and thicker walls quickly drives up the weight.
Because of this trade off between the modulus and the toughness, in my judgement this means, that there are applications where very high modulus material is appropriate. Applications where the lower weight, higher resonant frequency, higher efficiency, faster damping, etc. that are the result of the higher modulus result in a better performing rod, for example most fly rods. But there are also many applications where a low or standard modulus material is more appropriate because of the higher toughness, for example most boat rods, and there are many applications where an intermediate modulus material is most appropriate.

Because the term modulus of elasticity is mis used in advertising is NOT reason to discount the importance of the modulus of elasticity of a blank. It is proabably the single most important characteristic. Rather it is reason to buy our blanks from those manufacturers that are not misleading with their advertising, those that provide us with more information about the characteristics of their blanks not less information.

I do not mean to be a smart ass but if we quit using or discount all of the words that advertisers use in misleading ways we would all be mumbling to each other in a language that had a very limited vocabulary.

Welcome Back, Emory!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Hope all is well!

Mike