A few posts down Tom mentioned that he oversleeves all butt extensions. What is the reasoning behind this? I want to extend a large (nearly 1" OD) blank. Should I go looking for a huge scrap piece to oversleeve this or would the insertion method work? Also how do you know what material (glass or graphite) extension piece to use for different applications??

Oversleeving transferrs any load onto the stronger reel seat I.D instead of the weaker blank I.D.

If you do internally sleeve, wrap the original blank with thread like a ferrule but over the entire length of the overlap under the reel seat. I'd also try to fill up as much of the void between the rod blank and the reel seat I.D with epoxy to effectively transferr the load to the reel seat I.D. through the blank as there would be no voids or weak spots to allow seperate movement

The insertion method can and does work, but there will be some limitations at some point.

For any given material, an insertion piece can only be so strong. If you use a solid piece, that's the maximum you can get out of it and at some degree of a major weight increase most likely. As long as it's stronger than it needs to be under full load, you may be okay. Now with an outersleeve, there is not much limit on how strong I can make the extension. I can continue moving to thicker walls or larger diameter to get whatever strength I need. I won't be limited by the ID of the blank I'm working with. And, I can usually get the same or greater strength than an inner sleeve would give me at less weight.

Of course there's more to it than just strength. You want to try and maintain some continuity of properties between the blank and the extention piece. Any sudden change in stiffness or strength at that junction can result in a failure in one or the other. In the RodMaker article we discussed what makes a blank a good candidate for an extension and which blanks are not well suited to be extended.

We also have to be practical in these matters. On many rods, you aren't going to put enough load on anything to really test the extension or assembly. Now on heavier rods such as you suggest, you have to be more careful. If you do inside, you need to get the extention stiffness and strength up to at least that of the blank butt. So you'll be using a smaller diameter piece, so you'll have to move to thickerwalls or a higher modulus material in order to obtain equal or greater strength and stiffness than the blank butt. If you put a weaker or less stiff section in there, you could have failure at worst and some odd flex characteristics in the butt at best.

I won't tell you not to try the insertion method, but I would suggest you pay attention to wall thickness and material type if you do. Keep in mind that in nearly all situations where a heavy load is expected to be carried fully, sections are joined with an outersleeve. Witness the Uni-Butt ferrule, for instance. But you may be able to get by with an insertion piece, if you think it out well.

This is all pretty general in nature. The article had a lot more in the way of specifics and details.

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Edited 1 time(s). Last edit at 11/15/2006 11:05AM by Tom Kirkman.

Tom

In the spirit of experimentation, I am thinking of using carbon fiber tubing from a local retail source to extend a 10'6" s/s blank to 12'. Now the flexion of this tubing is minimal. The wall thickness looks good. and the intersect point should be reinforced by the reel seat area which will be a section of larger ID carbon fiber oversleeve that I will mount a plate reel seat on. I am attempting to build a rod strong enough to handle plugging for coastal striped bass while keeping the weight to a minimum.

Am I on the right track here or am I looking for trouble.




Derek L. McMaster
Rohnert Park, CA

Born to Fish, FORCED to Work

Scott, forgive me for using your thread for this. I have a similar question that I hope Tom will chime in again.

About a year ago, I added about eight inches to a blank via inner extension (didn't have the right size for oversleeving). Four inches went inside the blank. I pulled a single strand from some fiberglass cloth and wrapped that four inches with it, like a loose guide wrap, hoping it would aid in matching the taper of the blank. Also cut a strip of the cloth and wrapped the outside (with epoxy) like tape to approximate the blank OD.

The rod has only been used 4 or 5 times.

I'm hoping that I didn't create a disaster waiting to happen.

I have added an inch or two on surf rods where the customer just needed a little extra length. I've done this by inserting a scrap piece of rod blank into the butt. Unless you plan on making a long extension I think going inside is okay. Longer may be better with an outer extension.

I have repaired more than a few 60's and 70s era surf rods that turned out to have aluminum butts! The entire handle was built on aluminum pipe. Then the blank was inserted INTO that. An oversleeve of aluminum seems to have been popular for factory made surf rods back then.

My original post on extending a blank is what started this recently. my intention is to add 9" to a 7' 3wt glass fly rod. i think that the stresses generated on a three wt glass rod would be prettty light. i am not casting great distances and this is a soft, full flex rod. furthermore my butt section on this glass rod is .410. finding an oversleave with this inside diameter is not easy and will result in a very fat butt end to build my handle onto. i think i will go with the internal sleeve because of the nature of this rod. time will tell. i will definately overwrap everything for strength. what i am building is basically a "dink" rod for our small fish in the california san gabriel mountains. 7'9" glass three wt should be a blast on these fish. and it gives me the length for reaching.

I have a similar question for Tom: Is it OK to extent a rod using a wood butt grip as an overlay to the rod butt to extent a light action spinning rod 6 inches?

Ed Smith

Larry,

You'll probably be okay. I still think you build a nice handle on an oversleeze - you'd just have to ream the cork a bit more or forget about a wood insert seat. But an inside extension won't likely be tested on such a light rod. Try to use a piece with fairly good wall thickness, however.

Ed,

The only thing about wood is that it may be a bit heavy for such a light rod and if you use the wrong species or grain orientation you could have a problem with splitting. But properly thought out I'm sure it could work. All any of these things need to succeed is some good common sense.

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