Ferrule Wrapping

Discussion in 'Rod Building' started by Michael Dunn, Sep 7, 2007.

  1. Michael Dunn

    Michael Dunn New Member

    I'm working on my first rod building project and have gotten to the point of locating where to put the guides and trying a little casting.
    I've been using the Art Scheck book as my tutor but one thing I am a little unclear on is wrapping the ferrules.
    Art talks about making a plug to fit into the ferrule that makes it easier to prevent using too much tension and squeezing down hard enough that the fit between sections is too tight.
    The question in my mind is why not just have the sections plugged into each other when you wrap?
    Is it a question of being too awkward withe two sections together?

  2. James Mello

    James Mello Inventor of the "closed eye conjecture"

    Usually one has a shorter rod wrapper when donig this at home. Because of this, you'll usually end up working with individual sections at a time. If you want to do it while connected, and you have a wrapper long enough, go for it. Personally I've never plugged my ferrule ends as I just watch how much tension I'm applying.

    -- Cheers
    -- James
  3. Rob Ast

    Rob Ast Active Member

    I too am tackling my first rod. I am not at the ferrule wrapping stage yet, but it would seem to me that when working on the end of a section it would actually be easier to work with the sections joined - otherwise how do you balance the section in the rod holder?? any pointers from you experienced guys?
  4. James Mello

    James Mello Inventor of the "closed eye conjecture"

    Rubber bands to hold it down....
  5. yuhina

    yuhina Tropical member

    I did not have a stage. As the book described, I put the thread in a container and use two or three BIG book to hold the thread on the desk. (more books creak more tension). And just wrap the blank by hands. I did put a pen (the pen slightly wrap with duct tape) into the ferrule to make a joined section for easy handling.
  6. Rob Allen

    Rob Allen Active Member

    i'd like to see someone try to compress a graphite rod blank with thread tension especially in the ferrule area which is or should be at least stronger than any other part of the rod... welcome to the 21st century boys technology is advanced and much of the old school of rod building is no longer applicable.. just wrap the ferrule no need for any type of plug...
  7. EMPyre

    EMPyre Erich with an H -Top Water Soldier-

    I finished my second recently (and got a steely on it!) and I agree with not worring to much about the ferrule wraps. I am by no means an expert rod builder, I am however an engineer, and I'll tell that graphite should be consistant through out the blank. Ferrule wraps are now simply traditional and decorative. They do finish the rod well and add a nice touch to stand off segments. Don't bother trying to "reinforce" the blank with wraps or plugs, and you'll NEVER compress the blank with you wraps. Just put it together, make it look pretty, and go fish...if it breaks...well now you know how to build 'em so just replace the section.

    As for wrapping sections together...if you have a long bench you're all set, if not, then I hope you can position the section so that the end is inline with your thread, even then rubber bands (or fabic covered hair bands, to protect the blank finish) work well to hold it in place.

    I posted on a previous building thread that I have plans available for a great wrapping bench, built mine for $40. E-mail me if you're intersted.
  8. Michael Dunn

    Michael Dunn New Member

    Well, there you go. All I know about rod building is what I've read in one book. That's why I posted here. I knew I'd get some great info.
    My new rod building/fly tying room is my old reloading room which is 8 x 16. Nice little insulated/heated room I set up in a seperate building on our property.

  9. Jake Smulkowski

    Jake Smulkowski Throwing hoppers into baetis falls

    I think that ferrule wrapping is important - this is based on my experience slightly splitting a very expensive (technically, irreplacable, as it was a prototype) blank at a ferrule while doing a "static deflection test" to determine guide positions. (If you're not familiar with this test, it is accomplished by taping guides onto the blank according to traditional spacing formulae, then flexing the strung up rod, and moving the guides up or down to make the arc of the fly line more or less match the arc of the blank The blank was salvaged, at least after I wrapped the ferrules. I now either wrap the ferrules before static deflection testing, or tape them temporarily.

    I don't think a ferrule is a weak point in the fly rod - I think it illustrates the properties and mechanics of graphite or carbon fiber. The fibers are arranged along the axis of the rod, like a piece of wood. Imagine splitting a piece of wood in the traditional manner and then trying to split it against the axis...the same thing would be true with any fiber. Because the ferrule represents the end of the rod section, it is the easiest place for the rod to split. I think the tendency to split is going to be amplified on the more expensive blanks, which are lighter and crisper owing to the higher modulus, or stiffness of the material...if modulus is defined as the ratio of applied load to deformation, I think the reduced elasticity of higher modulus fibers would result in increased stress and shear on the other plane.

    Additionally, in my eyes, a wrapped ferrule is more aesthetically pleasing. I'm definitely not trying to start a pissing match or a debate over minutiae, but I know that I was certainly dissapointed when I damaged a special blank - especially because the damage was completely avoidable with little effort.
  10. Michael Dunn

    Michael Dunn New Member

    Thanks for the input. I'd decided I was going to wrap them before doing any test casting with the ferrules taped in place. I need the practice anyway.

  11. Rob Allen

    Rob Allen Active Member

    "The fibers are arranged along the axis of the rod, like a piece of wood. Imagine splitting a piece of wood in the traditional manner and then trying to split it against the axis...the same thing would be true with any fiber."

    A properly made graphite blank also has graphite running transversally in the female ferrule area that is why any rod without this transversal material will split out on the first cast.. any rod build without it is nothing more than a manufacturer defect. on a properly built graphite fly rod the thread adds no strength whatsoever to the female end of the ferrule.. if there is a rod blank on which it does the blank was made improperly.
  12. James Mello

    James Mello Inventor of the "closed eye conjecture"

    So here's a question. CTS is using some graphite scrim that is helical in nature as is T&T (I believe). I'm not familiar with their specific details of the ferrule area, so I wonder: are they still doing the helical wraps in that section for weigth reduction, or are they still doing a traditional 90 degrees to axis reinforcement.

    As for thread reinforcement on the ferrule it really depends on the manufacturer on what to do. Doing some custom work I *know* for a fact that for some manufacturers if you do a custom rod and don't have a ferrule wrap as long as suggested, they'll give you a hard time and may not replace the broken section. My guess is that it's for margin of error, but I *do* know of more than a few folks who do static deflections who forgot to do thread reinforcement and split the end out. Manufacturing defect?

    Also, you seem very certain of what you state. Is this because of involvement with the industry or just experience with rod building? :)

    -- Cheers
    -- James
  13. Rob Allen

    Rob Allen Active Member

    James i am involved up to my neck in the industry. Some people here i am sure know where i work but since we are not a sponsor of this page I'll leave names out of it. I am however the blank production manager for a rod company. I make blanks every day for a living..

    our testing with helical wraps has indicated to us that some transversal (90 degree) material is still needed for a strong female ferrule. i cannot speak as to what other companies do.

    I would say that any female ferrule that splits out regardless of whether it is thread wrapped or not is a manufacturer defect. but that is my opinion based completely on how easy it is to eliminate that problem..

    Here is where I'll cut rod manufacturers a lot of slack. graphite is incredibly difficult to get for a rod manufacturer. With the political climate we have now military contractors are placing great demands on carbon fiber pre-preg manufacturers. These manufacturers are making material as fast as they can and still not keeping up with the demand.. This leaves rod manufacturers out in the cold. We simply cannot use enough material to be important customers to the pre-preg companies.. Here is an analogy you go to a car dealer and ask to see what they have that's under 500 bucks. At the same time another guy comes in and wants to but a fleet of Ferraries. Who's gonna get the salesman's time??? We pretty much take the graphite we can get or we go without and once in a while a bad batch of graphite does come along. I heard about a manufacturer last year that was having a 90% failure rate of the parts they were making. Now this is a company that has been around for decades and a name every fly fisherman on the planet would recognize they simply got bad material and couldn't do a thing about it. SO to that extent i cut manufacturers a lot of slack when it comes to breakage...

    I personally think that failing to strengthen the female ferrule with transverally wound material is a flaw in the manufacturing of a fly rod but that's only because that's how i was trained and I don't see how anyone would expect a rod without it to not split out.. Maybe there is another blank building philosophy and technology that I am not aware of but my thinking is still that if it needs negligible strength that thread can supply then it is flawed to begin with..
  14. Michael Dunn

    Michael Dunn New Member

    Man, I'm glad I asked this and I'm just sitting back and enjoying these highly tecnical replies that are somewhat flying over my head. Thanks!:beer2:
  15. James Mello

    James Mello Inventor of the "closed eye conjecture"

    My experience is purely anecdotal, hence I was wondering why some manufactuers will give you grief over ferrule wraps not up to snuff in terms of suggested length... It is funny though as CTS says you can forgo the wraps if you want (as an example).

    Also in terms of neglagible strength can you quantify this number? Size A thread has a breaking strength of 2# or so... With a couple hundred wraps that does seem like a fair amount of strength.... But in relation to what? It could be a lot, it could be very little... :) BTW, this isn't to poke at the assertion, but rather to understand the factors involved....

    Finally, what specically are they using for the transversal fiber supports on rods? Is it the traditional fiberglass prepreg, or is it the same graphite on the the blank, or is it a lower modulus graphite?

    -- Cheers
    -- James
  16. Rob Allen

    Rob Allen Active Member


    i don't think any amount of thread wraps is sufficient to reienforce a ferrule as far as i am concerned if it isn't strong enough to hold up on it's own then it is a manufacturers flaw. In short thread i believe adds no strength to a rod at all..
    the transversal fibers are generally similar to the fibers that make up the rest of the rod it's such a small amount of material that the type of material isn't that critical it only matters that in create an entire wrap around the ferrule area. some manufacturers wrap it around the outside of the blank, these are generally covered with ferrule wraps for cosmetic reasons. Some manufactuers put the transversal inside the pattern to make a nice smooth transition, these however are not quite as strong as external ones, they are plenty strong just not as strong.. what matters most is that the transversal be an entire wrap and that they are 90 degrees across the blank.. Graphite fiber only retains it strength when it is straight as soon as it is distorted it looses about 40% of it's integrity. Most manufacturer defects are the result of distorted fiber.

    i don't think that quite answers one of your questions though i am trying to think of a good analogy..
  17. James Mello

    James Mello Inventor of the "closed eye conjecture"

    I guess the best way to put it is this... With a non deflected piece of graphite I'm sure that there's some form of tensile strength measurement. Without a ton of research I wouldn't be able to find it, so begging you forgive my laziness, this is the kind of info I'm looking for. I do remember reading a whitepaper from CTS where they mentioned the 40% loss of strength being an issue with helical graphite scrim.... All good stuff and I appreciate you taking the time to work through these questions.