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Bolsters and more bolsters

Discussion in 'Himalayan Imports' started by Svashtar, Oct 10, 2006.

  1. spiraltwista

    spiraltwista

    Nov 29, 2002
    Well you will have to work out what Bill & Simon said with someone other than me. I dont wish to play that game.

    But yes A loose handle is more stress on handle,blade & bolster, & yes plenty of kukri are rehandled in Nepal. Especialy the more recent ones.

    Lots over 100 years old still have thier original handles though. {if ther were put together as a tight fit in the first place, etc..}

    Hollows comments were not hyperthetical. Neither were Dans or mine. They all make sense.

    If you cant see that, so be it. its your choice, to view it in that way.

    Enjoy your veiw.


    cheers,
    Spiral
     
  2. munk

    munk

    Mar 22, 2002
    I have no idea what you are talking about any longer.
    No game- just two different opinions from two well known men. I'm just the guy putting them together on a forum for discussion. Their opinions are useful to figuring out what real use historic khukuris had, so we might better compare wear and tear on any bolster. That was logical.

    I understand very well Hollow and Dan. Their points are always well made.

    take care,
    munk
     
  3. Josh Muller

    Josh Muller

    Jun 22, 2003
    for those who have a good knowledge of handle construction and the strength of the various designs and methods of production - but do not know the common handle to bolster set ups that HI uses, it may be worth posting a few pics of what is generally going to be found from khukuri to khukuri here.

    i can only offer my uddha sword, becuase it is the only one i have broken a handle down on. i am not sure if this is how all of the uddha swords are set up, but this is how mine came.

    the handle slabs end at the bottom of the bolster, the inside of the bolster being filled with 2 seperate peices of wood. the distance between the top of the bolster and the wood peices that were initially in it (you can see the grey on the peice that was original, as apposed to the peice that i made) was filled with grey laha (or whatever it was). originally the brass bolster cover was brazed together rather then epoxied.

    i would personally be interested seeing how the normal wood handled uddha swords are constructred, as well as seeing a series of photo's showing what will commonly be found on HI's khukuri bolsters.


    i beleive my set up is very solid, but i was using brass threaded studs, long set epoxy resin and rosewood. were i using chisels and laha, im not sure i could do as well as i did. i have a great deal of respect for the quality of these blades given the situation of their creations.

    [​IMG][​IMG]
     
  4. munk

    munk

    Mar 22, 2002
    A guard like that would be real hard to forge from one unit of steel, but I can see a guard that simply swells out from thh side of the blade could be done. So you'd have a single peice of steel. Nice photos.

    munk
     
  5. Josh Muller

    Josh Muller

    Jun 22, 2003
    initially there was no gaurd present, it was just the handle slabs, then the 2 peices of filler wood with the brass cover plate molded and brazed over it. the bolster ended at the ricasso with laha showing, rather then metal covering it.

    i use the photo's with the gaurd because they do a better job of illustrating the filler wood and how it was all put together (basic design anyways)


    on aproy1101's bolo, it appeared as though the handle wood was shaved in a circle to be able to insert into the bolster, rather then having seperate peices of filler wood.

    is that the general way the bolsters are set up?
     
  6. Josh Muller

    Josh Muller

    Jun 22, 2003
    i appologize if im trying to have people reiterate things that have been said and shown a thousand times, but i have a limited knowledge of these things, so much of what is being said is flying over my head.

    without first knowing the basic construction of most khukuries (visuals are always helpful :D ) bolsters, i have a very limited ability to understand how they are causing failures.

    and beyond that, i havent seen an explanation or visual representation of what exactly is happening during such failures. i assume that a lot of the people who are reading this are the same. the closes i've seen is the gigantor thread about the cold steel square tang transition failures.
     
  7. munk

    munk

    Mar 22, 2002
    If you look at the design shape of the khukuri, breaking above the bolster is predictable. That's the part of the bat that will break if something wasn't done right. Does that make any sense, Seth?

    I'd like to see Dan's idea of as much one peice construction as is practical.

    munk
     
  8. spiraltwista

    spiraltwista

    Nov 29, 2002

    Thats good! There currant point is the same as mine.

    "Tangs need support."

    Spiral
     
  9. Josh Muller

    Josh Muller

    Jun 22, 2003
    alright, so... heres a ghettorific drawing of what the current vs. proposed bolsters that im seeing here.

    so far the only additional suggestion i've seen is the integral bolster, wich i think would be very difficult for the khami's to do, without making the blade thinner then it normally is. on a 1/2" thick blade, i would think that you'd have to iether start with a 3/4" thick bar, or i dont know... i've never actually forged a blade before :(... just seems like it would be very difficult to maintain the current handle thickness and have an full integral bolster... it would be easier to make a much much thinner integral bolster, but i still dont know if it could be dont on a wide scale while maintianing a limited time and materials schedule.

    this drawing is based on the assumption that all of the normal habaki style bolsters have the handle material slipping into the bolster, rather then having the full tang sword style bolster where there are two seperate peices of wood that fill out the bolster itself, and the handle slabs are pinned and laha'd to the tang.

    i can see where the integral bolster would be beneficial, if only because of the added metal in that area, and it would move the "breaking point" (again this is based on my assumptions from what i've read in this thread (and in general from the board)) lower into the middle of the handle.


    besides the integral bolster, what can be done to strengthen this junction? other then putting a good radius on the blade to tang junction, i have read very little in regards to the bolster actually providing structural strength to the knife as a whole, so this is all a new idea for me.


    *edit to add* - the other main suggestion is simply improving the fit of the wood into the bolster, so that there are no spaces between the tang and the handle matieral, and no spaces between the bolster material and the handle material, thus creating a more solid set up at the top of the handle. i am curious though, were you to use a dismantled khukuri (using the tang as your handle), would it be noticably weaker then with the handle material?

    is the idea of the breaking point because you have a gap between your grip point and the mass of the blade, creating an area where the blade can bend noticably, therefore increasing stress there?


    [​IMG]
     

    Attached Files:

  10. spiraltwista

    spiraltwista

    Nov 29, 2002
    Great stuff Seth!

    I personaly wouldnt use the words "breaking point" though.

    But following your idea Heres some pix to clarify.


    [​IMG]


    [​IMG]

    Kukris can be put together either way, but if the back of the blade {the piece at right anlges to the tang. {like the top picture.} is up against the wood there is less vibration.

    It is the vibration that helps lead to loose or poor fitting bolsters, cracks along top of the grip & loosens handles in time. It does put added stress on blade but that is only a problem if the blade is faulty in the first place.

    This is true whether the handle to blade fit is visible or is hidden behind a large bolster.

    Given the choice would anyone realy choose the bottom example?


    Spiral
     
  11. Daniel Koster

    Daniel Koster www.kosterknives.com Knifemaker / Craftsman / Service Provider

    Oct 18, 2001
    Only a few I've torn up have been that far apart...like I said most are 1/4" or so...1/2" being the extreme.

    The pic is illustrative, but not complete...you would need to show the laha that would fill the bolster. Laha is quite durable...but, for me, is not the best substitute for handle material. The handle should butt up against the tang (completely covering it) and the bolster should cover that transition...dress it up.

    I think that this issue is not a way of saying "H.I. products are substandard"...but rather is a way of showing how H.I. can take their already excellent bladesmithing to a higher level.

    How many of us have seen old knives with wooden handles and copper rivets that have lasted not just years, but generations?!
     
  12. spiraltwista

    spiraltwista

    Nov 29, 2002
    Very true Dan, Ive illustrated a 3/4 inch gap. I am glad most gaps are smaller than that!

    Laha is a good adhisive & a reasonable filler but I dont think it provides enough strengh when used to fill large gaps. not in comparison to a good hardwood. so we agree on that point, as well ,i think. & For instance I dont think I would want a handle made of pure laha, its good, but wood is better. IMHO.:D

    I agree it would be nice if one could suggest ways of improvment or to quote you " "H.I. products are substandard"...but rather is a way of showing how H.I. can take their already excellent bladesmithing to a higher level"

    Without anyone taking it as perhaps derogatory to the current production. Which has after all proven itself in sales to happy customers.

    As for your questian, I have lots of 100 to 150 year old kukri & knives with original handles.

    Spiral
     
  13. munk

    munk

    Mar 22, 2002
    Spiral, I was too damned provocative, and I apologize.

    Just because I try to call them as I see them, doesn't make me right. It's kinda sad in a way, a lonely road, sniff, why, it has aspects of a Greek tragedy, against all odds, one man's attempt to right a wronged world, a solitary figure against the Montana skyline, sob, (horns commence playing) .... it's ...it's ....


    just me.
    munk
     
  14. spiraltwista

    spiraltwista

    Nov 29, 2002
    Thankyou Munk,

    My input is to offer help, not to criticise.

    I realy like kukris!

    I want them to last for generations, & if thats with there original handles, thats even better in my book.

    Spiral
     
  15. munk

    munk

    Mar 22, 2002
    Amen.
    A dangerous line to cross, perhaps, one little word drawing us ever closer to Cult status.....



    munk
     
  16. TomFetter

    TomFetter

    Dec 6, 2004
    [documentary narrator voice] Gurgling whoops fill the cool desert night, as torchlight flickers across the walls of the munk compound. At the centre of the area, a small hooded group of men approach an enormous ponderosa pine log resting on a crude altar, exotic knives flashing red with the reflected flames. Soon we shall see these knives take savage bites from the wood, and any cougar zombies foolish enough to interrupt the rite.

    Acrid smoke wafts from smudges set at the altar's four corners, and at each end of the altar, acolytes with power grinders send showers of sparks from Nicholson Bastard Files careening into the night.

    We have entered into the mysteries of the HI Cult. [/documentary narrator voice]
     
  17. munk

    munk

    Mar 22, 2002
    A little known, obscure sect until the fiasco of 2009. Society was was not, and could not be the same again.

    >>>>>>>>>>>>>>

    Seth, great illustrations.


    munk
     
  18. Svashtar

    Svashtar Gold Member Gold Member

    Dec 28, 2003
    Well said Dan. BTW, what I have noticed on the MM is that the guard was cut two ways: one notch which will allow the guard to go clear up the tang to the start of the blade, and a second shorter notch at an angle next to it, evidently cut later, that allows the front guard / ring to go up just to the start of the bolster, where it then binds on the tang.

    The distance in this case from the front guard / start of the handle to the start of the blade was about 1 inch, which was way too far IMO.

    I know nothing about making knives, but was concerned at first that the guard is not a super tight fit to the tang/start of the blade. I was reading in Blade as to how to fit a guard, and the guy was using a flattened pipe to hammer the guard into place.

    I take it this is not needed for this type of knife? Or to solder it up?

    FYI, I got a piece of 1.5" diameter mild steel bar stock today. The smallest piece I could buy was 6" for $25. (The guy told me I was welcome to get a smaller 4" piece for $25 as well if that was too long. :D)

    I'm going to cut off a piece large enough to cover the blade up to the cho, and then see what I come up with, basically following Steve's suggestion on the bolster and epoxy, and his and Yvsa's on the welding. After 4 hours work I have the rings off and polished (getting the brazing off was a chore; wish I had a 2X72), the handle off, cleaned out, squared off and polished, and the tang keeper off and cleaned out. I ended up boiling the handle for a couple of hours to get most of the laha out, while a torch down the center for a few seconds got a bunch out as well. I plugged the handle end and filled it with acetone and let it sit overnight. After I dumped it out what was left was a powder that I could brush out pretty easily.

    I plan on flattening the spine at the top of the tang for about 1.25" so that the new bolster has an even bearing surface on top instead of the humped spine it has now. The bottom is already flat.

    I talked to the guy today who said he will TIG weld the whole thing (MIG splatters) up for me. I'll have to fit it to the tang as I go or it won't line up. Bolster to guard, guard to handle, then handle to rear guard. Wish I had a welder and knew how to use it, but the last time I used one it was oxy/acetylene with my Dad watching when I was 16, and it was pretty messy. I could braze it again, but that's just repeating the problem. Hopefully he won't charge a bunch to do this.

    Then I'll have to figure out how to get all the epoxy down inside it and fill it up before it sets up and get it in place.

    Dan, I was going to use JB Weld, but are you sure acra-glas is as strong? I use it for wood, but somehow thought JB was better for metal.

    I figure I'll have to put in a lot more time and some more $, but when it's done at least it should be serviceable.

    Probably the smart thing would have been to just take Yangdu up on her recall and send it back and apply the funds to something else rather than throwing even more money at it, but even without a handle it's a nice knife. Keeping it "as is" with the cracked brazing wasn't an option...

    Thanks as always for any input.

    Norm
     
  19. lizzardbone

    lizzardbone

    253
    Jul 28, 2006
    HI should incorporate forged in bolsters, (as Mr Koster gave an example of), on several models , and give it a trial run. Radius all sharp corners and transitions to the tang area to prevent stress risers.
    Keep the tradional style, but give the people another option.

    Recognise, inovate, overcome, evolve, and adapt.

    Raise the price a few bucks on units with this forged in bolster feature to comp the added labor. I for one, would be damn sure to purchase several without hesitation. Just my view.
     
  20. Daniel Koster

    Daniel Koster www.kosterknives.com Knifemaker / Craftsman / Service Provider

    Oct 18, 2001
    JB Weld = metal on metal

    Acraglas = metal on wood
    (also 2-ton epoxy)

    Gorilla Glue = wood on wood
    (also polyurethane glue, etc.)


    Best of luck, Norm. I'm sure you'll enjoy it! Might not be until a few weeks after you've finished it...:D :p :eek:...but the day will come.
     

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