I’m continuing Stan Massey’s subject to put it back in the limelight. I know I know we have gone in circles on this subject but there’s just something I’m still confused about here. Wouldn't the best way to find the presumable so-called spine be to put the tip of the blank on the ground and push down from the butt? Or to put the blank into a PCV type device at a slight angle and apply weight or pressure to the tip and rotate it to the stiffest point being on top and making that your spine? I understand that the stiffest axis is just that the stiffest axis not what we consider the spine. I would assume that the stiffest axis is the part of the rod that would normally concave so wouldn't it also be the best point to consider your spine thus making the stiffest axis your presumable spine? I understand everyone’s point above that there can be several different places that jump or kick and the tip might have a different reaction than the butt but wouldn't the average axis stiffness along the length of the blank be were you want to consider your spine rather it's the concaved or convex curve you prefer depending on your preference? Since I have became interested in rod building I have striped a few rods for eye replacement and have noticed that is what the manufactures have considered the spine is the stiffest axis or the outer nature curve. I've done test cast with the guides in different positions and have noticed that I would not have preferred a better position myself judging from feel. I think maybe to much info is just that TMI (too much information) I have no why of determining all the tiny inconsistencies and defects within the blank and don’t understand why the average rod builder should dwell on them. If I know of every twist bubble ext. within the blank I don't believe any of that info would help me determine what I would prefer to be my spine. Everything is math and I'm sure you could figure it out if you had the exact specs on all this TMI but who has the years to do all this? What I'm trying to say is even if I knew all the different criteria that determines a blanks so called spine it wouldn't help me one bit unless maybe I was a math god and mathematical it is impossible for a bumble be to fly. So with this all said, how far off would I be to remove the word spine from my vocabulary, find the stiffest axis, and according to my preference using this for my guide placement guidelines and go from there? Don’t get me wrong it’s very interesting and helps to understand why we need to locate a spot for guide placement but I don’t really see how the info does any thing to help us locate the area we prefer for our guides. See how I avoided the use of the word spine there? LOL.

You are not looking for the place or places where the blank "jumps or kicks," the effective spine is that location or orientation where a pressured blank comes to rest. The outside of the bend when a blank is in that position is referred to as the effective spine. And that is simply a reference point for a particular orientation, not the location of an actual thing.

The stiffess axis is not the spine, nor is it the opposite of the spine (it can be, but not usually). It is normally found along the blank's natural concave bend or warp. I often build my rods around this orientation. More info on this particular method is found on the FAQs page.

Finding the effective spine is easy to do, by a myriad of ways. Sitting the blank butt on a marble and pressing straight down on the tip usually results in a very consistent and accurate method for locating the spine. Obviously, shorter and stiffer blanks or sections don't work well with that method, however. Thus the various spine finder tools.

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What about solid blanks? I have an old (been siting in the actic for at least 20 years) Shakespeare NO-ss-190 5'6" medium heavy made in USA EED rod which I believe is glass (iching like @#$%& from sanding it down) and it dosn't seem to have a axis at all. Is it neccessary to find the spine on a solid blank? If so will a normal spine finder tool do this or is some other type tool needed? I'm rebuilding this rod because it's practice and the old wood handle is beautiful and I think it would look good on display. I plan on keeping all the original parts ecept for the cork forgrip which has been eatin away, the original thread of course, the reeal seat which has cracked, and I plan on replacing the two original guides and the tip. I doubt I'll ever use it since i'm an inshore fisherman but I would like to make it functional anyway and would like to locate the spine if such a thing exist on a solid rod. Also, I noticed the tip is several times larger than the guides. whats up with that? If all else fails I can build it up and use it as a hole finder while wading. Suckers built like a tank. I didn't see anything on solid rods in the Volume 2 - Issue #4 issue of RodMaker or Volume 5, Issue #3 of RodMaker unles I've over looked it.

Thanks, Nick

All shafts, tubular or solid, will exhibit some sort of spine effect. Your solid rod can be treated just like a tubular one.

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Recently, I have changed my thinking. I used to always use the spine as my guide. Now, it the blank has any bend at all, I use that instead, and many top quality blanks have a little bend. John Butterfield

John,
I agree with you completely. I do it the same way you do except on very powerful rods with pronounced spines. I know that there are differences of opinion about this but I believe that the spine an inherent imperfection in the blank and the more pronounced the spine the bigger the imperfection. And that a perfect blank would have no spine at all. I think that in time blank manufacturers will be able to give us blanks that have virtually no spine or at least spines that are very difficult to detect at which point we will not have to be concerned about it.

Nicholas Whipp patented a process by which his blanks have definite spines, one exactly opposite the other. By altering the shape of the inside of the blank (essentially creating two perfect "flats") he ends up with two opposing axis that possess greater wall thickness than other other point on the blank. The blank does not want to flex (compress or stretch) on either of these particular axis. Thus it always does so exactly between them.

I suppose his theory was that if you can't get rid of the spine, you might as well build one you can control.

His health was failing the last time I spoke with him and I believe his patent was for sale. It's an interesting concept and his rods and blanks were quite popular with many fishermen during the late 1980's and early 1990's.

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Nicholas,

The subject of the spine and what it is and what effect it has on a rods has benn bounced around ever since Lord Nelson was a lad.
I for one am fed up of not knowing the real truth. My view and it is only a view is that we as rod building community do not really understand in totality what this spine thing is all about. My eveidnce to support this view is the fact it constantly is up for discussion and debate. Now it can't be a philosphofical debate becuase there are actual reasons as to what we call a spine to exist.

These reasons are invoiolate if we can get to the bottom of it. We have not. So my plea is unless we have definitive provable answers we should qualify any thing we say to the effect that it is unproven or not otherwise we just perpetulate mith and garbage.

What I cannot understand is why the major and for that matter the minor blank manufacturesr do not enter into this debate with a view to resoving this issue on a scientific basis once and for all.
I certainly do not want my son in twenty years time to be having to read though the same old tired stuff much of which is hopelessly wrong.

That's my two cents worth and I hope I did not upset anyone on the way thay is not my intention. We just have to wrap this thing up once and for all.


Regards Mike Oliver

We certainly know what causes it and what it does and does not do. But many have not taken advantage of the literature, tests, etc., and thus still have questions about it. But the information is available. It's not a mystery at all and there is no debate among those informed and educated on the matter. Newcomers will always have questions about it, but that doesn't mean it's a mystery. Just that they haven't availed themselves of the proper information, yet.

The manufacturers prefer not to utilize the spine in building their factory rods. This mostly because building on the spine means the rod will look crooked to any customers who walk into a store/shop and sight down the rod - they always do this with the guides pointing straight up or straight down. Thus, the commercial makers build on the blank's straightest axis.

Because rod stability is determined by guide location and not by spine orientation, most commercial rod companies do not place any real importance on the spine. Having the customer see a "straight" rod is most important when sales are considered.

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Tom,

My point I believe still has validity. We still have builders on this site that I respect still debating this issue . I am not convinced it is still clear cut and final in scientific factual terms.

I stongly agree that line of best fit is the most probable route that manufactures go if they make any effort at all in this regard and for the reasons you specified. But this does not prevent them from explaining what and how the spine is generated during the manufacturing process, plus the actual affect on a finsihed rod. This puzzles me, they have nothing to loose by doing this and of all people are best placed to put this to bed.
In spite of all the information that you say is available Tom, this spine thing is not going away and it's not just newcomers who are asking the questions or making possibly incorrect statements not only on this board but to our customer base out there to whome we have a great deal of responsibility to when talking through such matters with them.


Regards Mike Oliver

I guess I don't know what you're asking for. The scientific reasons behind the spine effect are in print and we have the tests to prove what the effect does and does not do. Many have not read any of it, or have overlooked it. Then you have so much in the way of general myth regarding spine that will continue to circulate for some time (this is a major problem). But the facts have been in for some time. For many years actually. It's not a mystery.

I don't expect the discussion of spine to ever go away, nor the discussion of color preservers, or epoxy adhesives, etc. The facts are available but many don't know where to look, look in the wrong places, hear things and accept them as fact, etc. That's just the nature of the beast. It's a process of continuing education. 10 years from now we'll still have people on this site asking why their epoxy finish remains tacky, even though we've long known the reason why.

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Mike - you could put all the scientific studies on rod spine you want on this board today and tomorrow someone will post and ask how to find the spine, how to locate it and where to put it to elminate rod twist. All the same old questions will continue to be asked over and over and over no matter what information you find, read, offer or post here. If your goal is to "settle" the spine argument once and for all just forget it. It's already been settled and decided upon but people keep on asking, arguing and wondering. They always will no matter what you do.

I guess that was my point. No matter how much information you make available, no matter how factual and proveable it is, the same questions and arguments about spine will be right back in a few days.

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Tom and William,

I guess that's my point to a degree. But still I ask why is the silence so deafening from the very people ie the blank makers on this issue.
I guess I am going to close down on this one as we are in danger of getting no nearer to closure than at the start.

Thanks for your input.

Regards Mike Oliver