Several of my blanks have major and minor splines, and I just go with the major one. But I have two blanks that have a double spline, both about equal in power. In one rod, they are 180 degrees from each other. In the second rod, they are about 90 degrees from each other.

* In either, does it matter which one I use?
* In the blank where they are 90 degrees from each other, should I split the difference between the two, or just pick one of them?


Also, I have a rod that has absolutely NO spline! The friend who got me into this stuff tells me it is a rare blank, with very even wall thickness. He tells me that I should keep it for myself or give it to him. What do you think?

TH

If there is no noticeable difference, then look at the "straightness" of the rod. If it tends to curve in one direction, place guides on inside of curve for spin/fly and outside for cast. From what I have heard, some do this irregardless of where the spine is. If you have equal on 90 degrees, I wonder if it would work to "split the difference", in otherwords put the guide right in between the two spines. I haven't had this arise, but just throwing out an idea. The ulitmate test will be with test casting and most importantly stress dist. testing. This will indicate if the rod wants to twist a little. Hope this helped some. I am sure others will chime in shortly.

There is only one true spine (effective spine) on any blank. It will be the more pronouced of the two, or three or what have you. If you are using a vertical spine finder, it will be much easier to tell which is the more pronouced. Failing that, sit the butt of your blank on a marble and press down on the tip. It should flex moreso in one direction and the outside of that will be your effective spine. Use it however you deem necessary for the specific rod you are building.

All rods will have a spine effect, some more than others. The blank you have with no apparent spine can be a real treasure, or not. Many rod builders prefer blanks that exhibit a strong spine rather than none at all.

By the way, consistency of wall thickness is only one of about 7 major items that contribute to the effect we call spine. More to come in a very near future issue of RodMaker.

Also, do a search of this board's archives to get more information on rod spine. There has been some good info here on that subject over the past few months.

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Tom,

Out of 16 blanks, all of them were "normal" besides these three. First thing I did was mark all of the splines, and these three were ones I set aside for further examination. I'm using a vertical spline finder (ball bearing) but they seem very equal, even with my eyes closed. Maybe some kind of sensitive scale could be hooked up, I don't know.

The one with no spline is a true oddity. I checked it from tip to a very deep bend, and nothing. Rolls smoothly all the way around. But I don't see any particular benefit, besides the rarity. Is there any?

I REALLY like the one with the splines on opposite sides. Seems that it will both cast and handle fish well.

The one with the splines at the right angles, is the one I'm not sure what to do with. I'm leaning towards splitting the difference, and putting the splines at the 10 and 2 o'clock positions, unless someone tells me something different. This seems to go best with the curve of the blank. Thanks Elrod, for that suggestion.

TH

Anything will work, but some better than others. Remember that when fighting a fish, the guide location will determine stability, not spine location.

On the blank with two very equal spines, affix the butt and hang a weight on the tip. Measure the total deflection from starting point to the point where it deflects under the weight. Now do the same on the other axis which seems similar. The one where the blank deflects the most is the one I would build around, if you are building that way (around the spine and not the stiffest axis). In either event, I think I would pick one or the other rather than splitting the difference.

A blank with two spines, exactly 180 degrees opposite each other, is something many rod builders prefer.

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I have been reading these postings with great interest. Now I find myself confused by Tom's last post. Wouldn't you build around the "side" or axis that deflects the least? I think I have misunderstood somthing.

Thank You
Bill Doherty

From what I have read it would appear that you can make several slightly different rods out of the same blank by positioning your guides in different places relative to the spine. And that there is no one 'correct' place to locate guides relative to spine. I have followed some of the ideas I have read in Rodmaker and sometimes just use the natural curvature of the blank as the stiffest plane and build that way for maximum fish fighting power. Or I might put the guides on or opposite the spine if I want straighter casting. Understanding that it is whether or not the guides are on the bottom of the rod that creates rod stability frees you to do several things with the same blank.

Before Tom has had a chase to explain what he meant, I re-read his post a few times and figured it out. Sorry to have questioned what you meant Tom. Build on the actual spine not the stiffest axis, if he is inclined to do so. Of the two "spines", that would be the one that deflects the most. DAH! I guess if you can't spell "something" correctly, you must be alittle slow.

Thank You
Bill Doherty

I wish I could explain things better in words. The magazine is easier because we have the use of all those photos!

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Tom and others,

I thread-wrapped a string to the very tip of the rod, and attached a 2 lb weight to the string. I set the rod horiz,so that the weight was barely lifted off of my desk. I then rotated the rod, and again, the stupid splines seem equal. The weight would touch on the softer sides, and lift 1/8" at two points on the blank. I finally gave up and picked a spine and marked it. Enough of this nonsense. The rod will be fine

Thanks for the help!

TH