Any help on this will be greatly appreciated. I'm building a rod for a friend of mine and just made a stupid mistake. I forgot to measure and mark off the portion of the blank that will be exposed through the blank exposed reel seat. Scuffed it up...damn it! Thank goodness I haven't mixed up the rod bond yet. Do any of you more experienced rod builders have any tricks up your sleeves for covering up minor scratches on a blank? What I'm thinking now is a putting a thin coat of veneer or epoxy over the marred region before installing the seat. Any input will be helpful. Thanks,

Matt

If you scuffs are just in the finish I would take it down to bare blank. I do this on purpose on the majority of my builds any way.
What I use is a green Scotch Bright pad, and wet sand it at a sink using dish soap to aid in lubrication while sanding so I don't cut into the blank

Matt,

Is the blank colored or just gloss over graphite or? The reason I ask is if it is gloss over natural graphite, smooth out the scuffs and go over with a very very light coat of epoxy finish. If it is a colored blank and you did not scuff to the original blank color smooth out and again apply a very very thin coat of epoxy finish. If it is a colored blak and you scuffed down to the original blank color just smooth out and clean up the area that will be exposed and go with that if it works for your friend.

Tight lines,

John Hernandez

Matt,
I would remove all of the finish where the hole is in the reel seat and the fishermans hand will be. Believe it or not you will get a very slight increase in the rods sensitivity.
For those that do not believe this or those who wonder why this is the case: When a vibration travels up the rod any time that it comes to a new material there will be what is called a discontinuity at the junction of the two materials. At a discontinuity part of the energy in the vibration will pass on through the new material but part of the energy will be reflected back toward the tip of the rod. How much will pass through the new material and how much will be reflected is a function of the ratio of the mechanical impedance of the two materials. If the mechanical impedance of the two materials is simular then most of the energy will pass on into the new material but if the mechanical impedance of the two materials is quite a bit different then most of the energy will be reflected back. The difference in the mechanical impedance of the blank and the typical coatings that are used on blanks is not huge but it is significant.

Thanks for the input fellas,
The blank is graphite with a satin finish on it. I'll be taking the finish down to the blank, carefully. I appreciate it, thanks again,
Matt

What Emory says is certainly true, but the amount of sensitivity increase in this case would be so slight that the human hand could never realize it. I'm all for building as light and sensitive as possible, but we also have to be realistic in our goals and expectations.

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if it has a satin finish you can hit it with a clear coat with a satin finish/flatteners in it...i have also used wipe on urethane to "fix" an area on an SCIV where i moved a guide...you cannot find where i did this on this blank

Matt,

Just a possible alternative. I have some pearl finish film material used for refinishing drum sides. I have wrapped the rod blank below the seat cut out with this material before. Turned out pretty neat. I have two colors, blue pearl and cream pearl. I'd be happy to send you some if you would like.

John.

JLS Custom Rods
Cassadaga, NY



Edited 1 time(s). Last edit at 03/03/2011 08:26PM by John Straight.

Tom,
I agree that the affect that the coating will have on sensitivity will not be large but it could be significant enough to be felt. It depends on how much difference there is between the mechanical impedance of the raw blank and the mechanical impedance of the coating. Blanks are made primarily of materials that are elastic (carbon fiber and fiber glass) while the coatings are going to be plastic not elastic so I would expect a significant difference in their mechanical impedances.

Yes, but I'm very confident that the difference you're talking about - the absence of finish in that area alone, is so small as to be absolutely insignificant to the human hand.

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

Well everything's glued up and looks pretty good. I wound up taking it down to the blank material. The rod is an 8'6" fast action salmon/steelhead rod that's going to end up with a spiral wrap and fairly small running guides. I don't know if it could get much more sensitive...lordy help them fish! Thanks again for helping.

Matt

Matt,
This has happened to me on an occasion, and I simply did a continuous thread wrap from the butt grip to the rear handle. Normally, this is only a few inches, and the slight added weight normally helps to better balance the rod. Plus, you can do a nice wrap, or weave in that area to dress up the rod, and completely cover the blank.

Take care
Roger

Tom,
I think that maybe you are missing the point. Removing the finish in the area where the fisherman's hand contacts the rod obviously removes an insignificant amount of weight and has almost no affect on the rods sensitivity but removing the coating in this area eliminates the reflection of part of the energy in the vibrations by eliminating the dioscontinuity at the junction of the blank and the finish. It is not the weight reduction it is elminating the reflection of energy that increases the sensitivity a small amount.

Emory,

With all due respect - I think you're missing the point. Nothing you do in that small area, whether it's weight reduction of that amount, or eliminating the discontinuity between the blank and finish, is going to amount to a hill a beans. What you're talking about is absolutely insignificant insofar as even the most discerning human hand would ever be able to tell.

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Tom,
Your comment "Nothing you do in that small area" is missing the point.
The increse in the amplitude of the vibrations has nothing to do with the size of the area where the finish is removed. The elimination of the discontinuity and the reflection of energy that results is mainly what will determine the size of the change in the amplitude of the vibrations.
The reflection can be large or small depending upon whether the difference in the mechanical impedance of the two materials, finish and blank materials, was large or small. The mechanical impedance is a function of the mass density and the elasticity of the two materials. The finish is plastic with poor elasticity and relatively high density while the blank material is elastic with lower mass density so the difference in the mechanical impedance can be large and therefore the discontinuity relatively large and the affect on the vibrations significant.
Whether a significant change in the amplitude of the vibrations is going to be detected by the fisherman is going to also be a function of the weight of the rod and reel. If it is a heavy rod and reel then I would tend to agree with you that a fisherman is unlikely to detect the difference but if the rod and reel were a very light then I would disagree with you.



Edited 1 time(s). Last edit at 03/04/2011 12:52PM by Emory J. Harry.

Emory,

You're still not getting what I'm saying - the amount of sensitivity loss or gain from what you're talking about, from a real world practical standpoint, is not significant enough for any human on the planet to be able to tell the difference.

Maybe it's time for you to work on a device, or method, for not only measuring relative sensitivity, but translating it into figures that would accurately access if the amounts involved are enough to be of practical value.

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Tom,
I certainly agree with your last comment.

Too many folks really get bent out of shape with respect to saving a gram or fraction of gram there.

Then they put a 20 oz reel on the light blank and don't think that they have what they want.

Yes, I certainly agree that it is generally in the interest of the rod builder and client to have a rod that is built with light weight components. But, there are times when it makes no sense at all to put some of the components on the blanks that some rod builders are doing.

As you have mentioned mayny times before.

Use the right blank, the right rod components to do the job that the rod needs to do. then, the builder and user of the rod will be very happy. It really doesn't matter if the rod weighs 4 grams or 14 lbs. If the rod does what the client wants and needs, it is the perfect rod for the client.

Take care
Roger

Right - diminishing returns is what we're talking about. Still, it would be nice to have some sort of method for quantifying what we call "sensitivity" both on a relative scale and by some means so we can compare to what the human hand is capable of actually feeling.

At the Expo last weekend, I had dinner with Jason Brunner from St. Croix rod company. He said they were working on a "machine" that would allow them to make comparative measurements of a rod's ability to transmit an input to an output. It'll be interesting to see what they come up with.

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Will the fisherman be holding the rod with his hand in the bare blank between the split grips?

Gentlemen, it's a fishing rod, not an engineering thesis.

john backos Wrote:
-------------------------------------------------------
> Will the fisherman be holding the rod with his
> hand in the bare blank between the split grips?
>
> Gentlemen, it's a fishing rod, not an engineering
> thesis.


Nope, cork rear grip. I'm building the rod to be as light as possible. To be honest, I don't think that the fella the rod is going to will be able to notice if there was an increase in sensitivity by taking the finish off of the blank where it is exposed through the reel seat. Have to say that I love these boards and the friendly debates