Bolsters and more bolsters

Svashtar

Svashtar

Joined
Dec 28, 2003
Messages
4,791
Guys, the horse is long dead but I'm gonna wail on him till I get it, sorry.

I have seen you all write about the bolsters for years, but it wasn't until I got the Mm apart that I finally got it. I have several habaki bolsters that do fit partially over the blade, and just assumed they _all_ did that and supported it somewhat.

I also thought the MM bolster did this, but once I got it all cleaned out I realized that the friction I had been feeling was just the laha inside it, and the friction fit of the cutout in the guard to the tang. The bolster just barely covers the blade.

So the bolster really just appears to be a transition from the blade to the guard / handle designed to hide the joint. It doesn't really "bolster" anything, correct?

The old standard bolsters also did not support the blade then? I guess that the habaki lies further back from the blade leaving more of the tang unsupported, whereas the standard ones were fit more to the blade and supported it.

Not saying this is bad as I have a ton of knives with all types of bolsters and they have held up, just trying to understand it all over again.

So, other than cosmetics, I guess I really don't need it, and could really just have a guard there.

Steve had this great suggestion:

ferguson said:
Make a new bolster out of solid steel. It probably wouldn't be difficult, just time consuming. Weld it to the disk. Weld the disk to the handle. Put piece of masking tape over the small hole in the butt of the handle. Fill handle with epoxy throug the bolster hole. Stick the tang down through the handle, poking through the tape in the butt. Voila
Click to expand...

I doubt it would be difficult for Steve, but I figure I could do it in a few months. :D But it's a good idea. Once I had the steel bolster slid over the blade, then the guard and the rest of the handle could be dedicated to supporting the tang.

Again, thought this was what I already had, but most of the support comes from just the guard as is.

Thanks for letting me explain this to myself and for any input. I guess I just confused a bolster with a ferrule all along...

Norm
 
I have noticed that the "new style/long" bolster on the HI knives I have, provide a friction area that helps retain the knife in the scabard. I prefer them because of this. That is the only practicle purpose the serve for me. Could be that there is more purpose to it? I dont know.
 
I'd like to see what Dan says here. I think he's rehandled more than anyone. From the ones I've done I think it serves to prevent splitting much like a ferrule, but I've only removed three handles.

On a side note. After removing a few bolsters I am amazed at their construction. I'd love to see exactly how they get the brass to do that.
 
After removing a few bolsters I am amazed at their construction. I'd love to see exactly how they get the brass to do that.
Click to expand...
I realize that linking to another forum is not considered good form, but AFAIK the information here isn't available elsewhere. Nasty, if this is too big a breach of forum netiquette, please delete with my apologies.
Berk
 
I think antique bolsters were so small they were almost just a tidying feature that also prevented moisture entering the handle in the area of the laha , prevented chips in the area strength was needed.e

The kukris made without bolsters seem just as strong & reliable to me.

Large bolsters can work as a ferrule if the wood is perfectly fitted inside them. {this is sometimes done on true old village kukri.} Most kukris I ve dismantled from post ww2 the fit is very imperfect & provides no strength.

So it is back to a tidying, preventing chips & perhaps moisture reducing feature.

Sadly large bolsters can also hide sloppy workmsanship. Not much to hide under a small bolster.

As an aside When English kukri were made in ww1 the bolsters were stamped out in one piece, In Afghanistan they cast them. And Berkleys link shows the western interpritation of the Indian & Nepaly technique.

The kamis cut make & fit a bolster in about 5 minutes , its amazing!

As is most of what they do.

Spiral
 
I think that if you look at the fit of most of the khuks who have handle cracks or handles that break clean off, or that have laha rattling inside, you will see that the wood of the handle only extends partially up into the bolster and the bolster doesn't support the blade at all.

The ones I have removed the wood only went maybe 1/2 to 1/3 up into the bolster, leaving a large area that is (hopefully) filled with laha. The blade on the ones I have removed set on top of the habaki bolster. I have never removed a traditional one cause they have never caused any trouble.

I think a shorter bolster would force the workers to make a better fit of wood to blade.
 
Technically speaking, a bolster is anything that supports the junction between the blade and the handle - even on full tang knives. "To bolster" means to support.

That said, the bolsters on H.I. kukris definitely act as ferrules which are added to knives trim up the blade/handle junction, and to protect the front of the handle from the inevitable slip-ups.

As far as I know, ferrules usually don't overlap the blade. There's really no point to it...since the ferrule is more for protection, than for structural integrity.

The troubling part is when there is a significant gap between the start of the tang and the front of the wood handle.

I have taken apart a bunch of kukris and for the most part, that gap is usually only 1/4" - 1/2" at most...and it's filled with laha.

The problem, I believe is this:

A while back the suggestion was made to incorporate habaki-style bolsters onto the kukris. If I have read things correctly, this was a response to the sometimes messy transition between the blade and the bolster/ferrule. A true habaki covers part of the blade and is fitted to it. Had it been done this way, it would have been great! However, kamis being kamis...they did things their way and we now know the results.

What we need is a good technical cut-away drawing showing the habaki extending over the blade by 1/2" minimum. This would not only cut down on "cho-creep" but also help close the gap between the front of the tang and the front of the handle.
 
Good definition of the word Bolster Dan , but in Nepal it is called by the kami the Kaj or Kajo which I understand means "the Work". Or something along those lines? {Happy to be corrected though.}The word Bolster is are western interpritation of it. {In Devangari Bolster is "Thamnu"}

There are many types of bolster some are just 2 shaped pieces of solid metal rivited or welded to each side of the blade, many ww1 one are a solid horshoe shape of steel dropped over the blade, then brazed at the base, that type protect the end grain but nothing else.{IMHO.]

In antique kukri Ive never found a laha gap as large as 1/4 inch & 1/2 sounds massive to me. But each of us will have a different perspective.

We all seem to agree the bolster should be full of handle though, & that gaps between front & tang & handle are a potential weakness in worst case scenarios.. {That feels a familar old line to me...}

Spiral
 
Is the gap associated with the Habaki bolster? It is unclear to me in this discussion.

I don't recall more or less failures with the Habaki bolster vs the traditional. This has been confirmed by other forumites. I also believe that shoddy worksmanship can be covered by either style bolster and handle. The 'joint' mentioned seems to be covered with the traditional, as well as habaki. What am I missing? One of these oft repeated phrases that mean nothing, or something?


munk
 
For me Munk the important word was "potential" Any tang that isnt supported is potentialy weaker than a supported tang. whether habaki or traditional.

To me it appears Dan & Hollow who have both hade kukris who need repair have reached the same conclusian?

I think Dan wants habaki bolsters but done properly,with the kami retaught to put with the habaki part over blade not the tang.{As a true habiki is meant to be.}

Hollows idea & mine coincide, if bolsters are small there is less chance of poor fit inside them when the kamis are working fast.

Thats my interpritation of what was said. But of course I may be mistaken.

Spiral
 
That makes sense. But it is still true there were no more failures with the Habaki than traditional. Many other formuites have come to the same conclusion. I know, because I asked when this issue was raised in the past.

Like a lot of folks, I like the look of the traditional.


munk
 
I have no way of proving this and it is pretty much speculation on my part but I believe that in general since the habaki type results in a greater distance between where the wood or horn ends and where the blade starts that you would see less stress cracks in horn khuks using a traditional bolster. I have had several after chopping hard stuff get micro cracks along the back of the handle near the bolster.
 
Well Munk I figure if someone had collected evry kukri that failed together, & had stuided why, then futre kukri could be adjusted to rule out the past reasons for the occasional failures.

Thats my reasoning.

I know that most kukri that are showing handle problems after 30 to 100 years have imperfect tang to handle fitting, especialy particularily under the bolster & or buttcaps, or large drilled holes totaly or partiatly full of laha.

I suspect that failures that occur in years 1 to 10 or up to any age will often be the same reason.

Fully supported & well fitting tangs last down through the generations.

Spiral
 
Spiral; habakis failures were no more prevalent than tradtional bolsers - WHEN HI MADE THE KHUK,
Naturally, I have no observance of other manufactuerers.

Other observators?
Best of HI forum who know a lot more of metaliurgy than I.

So, I have; 'might have been": as opposed to 'what was."


If you suggest more decades were needed for relevant statistical study I agree; especially considering peer companies who have sold less than once percent of HI total.

Otherwise, yes, by the time a khuk makes it one hundred years we have a certain amount of trust in it; on the other hand: there are those betting when it will fail.

"

"I know that most kukri that are showing handle problems after 30 to 100 years have imperfect tang to handle fitting, especialy particularily under the bolster & or buttcaps, or large drilled holes totaly or partiatly full of laha." Spiral


Oh, do you? then you are a better sampler than any known human I'm aware of. You base this on what??!! Uh huh.
At any rate, I'd offer a HUNDRED years as "NOt bad" when it came to human tool use and abuse, particularly when it concerned a handle.
PIe in the Sky considering HI products; ask any 'sample' of use you wish.
munk
 
This has been incredibly helpful. Thanks especially to Spiral and Dan and to Berk for the great link. I finally get what has been going into my ears all these years. (I'm a real quick study all right. :rolleyes: )

Once I got this apart I understood many of the comments others have made over the years. Till now I thought the objection simply was that the "habaki" part of the bolster was doing the support rather than the older bolster which I assumed supported the blade better. I see now, on this one at least, that it is not really on the blade at all. (I do know that I have some where the brass sleeve is over part of the blade though.)

Making a steel bolster that slipped over the blade for at least the last 1/2" and was attached directly to the guard would give great support to the handle.

The inside of this handle is not a big place, so any wood or metal inserts around the tang are necessarily going to have to have epoxy around them. Ideally I would just weld the whole thing to this bolster and epoxy it all up like Steve and Yvsa suggested.

I may end up sending it all to Dan, but hopefully I'll be able to do something with it. I really don't like the idea of putting what I consider to be a ferrule back on it and leaving the tang solely supported by the thin guard material in front, a full 1" back from the end of the blade, no matter how strong the new welds are on the handle.

Thanks again. You guys are the best. :thumbup:

Norm
 
I wonder if there is any way to make the khukuri better, rather than a yes - no discussion of Habaki vs tradtional bolster.

You know, if we came up with something, I'll bet Yangdu would give it a listen.


muink
 
The honest-to-goodness best way to make the tang is going to be forging the entire thing as one solid piece (blade, bolster & tang) like the latest batch of Brazilian knifemakers are doing to their integral gouchos...and how it was done on an antique kukri I had the priviledge of inspecting.

http://www.bladeforums.com/forums/attachment.php?attachmentid=56920&d=1150385243
http://www.brazilianbladesmiths.com.br/dornelespicfiles/chef.jpg


http://www.bladeforums.com/forums/attachment.php?attachmentid=61072&stc=1&d=1160632905


This will be even better/stronger than a regular full tang. It will also be a bit heavier. Even with a hidden tang...it's better (if bolster and tang strength are priority one).


munk - I believe spiral was saying that when we look at kukris that are 30-100+ yrs old and see where they are failing...it is in those places/ways. I would agree, based on the limited number of antiques I've dealt with. I've also seen some very sturdy, old blades that the handles were long gone, but the tangs were in perfect condition. Despite be short "rat tail" tangs and not even held in with a pin.


I'll reiterate my position on this:

I believe that the failures are few and far between. When you move as much volume as H.I. does...it's bound to creep up now and then. The area we were lacking in was final testing - which has now been changed. To me, that keeps H.I. at the top. I do like other manufacturers wares as well...but this isn't about them. It's about whether or not H.I. will maintain a standard, which it is doing very nicely. Thank you, Yangdu.


I like the looks of the habaki bolster (when short and overlapping the blade). I also like traditional. I also like a solid steel piece (which is 2nd best only to the integral idea mentioned above). I just want the confidence that the tang is completely buried in the handle. The habaki part of the bolster should only cover the blade, and not any of the tang. And yes, I do believe that there have been more failures related to it, than to the traditional.
 
Munk,

Anyone reading this thread for my comments would do best to take the gestalt of them, & not pick individual sentances to mix there on veiws with it to put down other Nepali companys & then also to try to use them as if I am saying HI dont have a good track record.


Thats not been my statement or implication. Evryone knows HIs track record for strength.


You say do any other companys make Habaki Bolsters? {if so I expect they dropped the design quite fast. } {I cant be bothered to check my photo files either, because, I realy dont care about globalising this argument.}

Thanks Dan for the clarification for Munk on my comment on 30 to 100 year old handles. You explained it exactly.

Munk my comments were based on the expierience of having bought about 485 to 490 of them in the last 5 years & studied each of them in depth. Not to mention all the input I have had from other collectord & makers, & the hundreds of kukri I have seen in others collections. Whether you like it or not that gives me a perspective of Nepali , Indian, English & Atghan made kukri.


Sorry you think my input is "pie in the sky" Munk.

Not much I can do about that. Its your judgment.Your entitled to it.

Thanks Svashtar it makes it all worth while when someone comprehends the conclusians that I {& Dan, Hollow etc.} have reached.

The Strongest tangs have the fullest support.

And as Dan says "I just want the confidence that the tang is completely buried in the handle."

& Thats how its achieved whether you think the fact Ive pulled apart & examined more kukri, both good & bad than you would ever belive is "pie in the sky" or not. {& after all Dans probably pulled apart more HI kukris than anyone.}

Spiral
 
Yes, Spiral. I shouldn't have posted at all last night. Not a good mood. I was too feisty.
I honestly figure the reason for the traditional bolster was to keep operations simple and with the least expenditure of materials.
Even forumites who didn't like the Habaki bolster admited it did not fail any more than the standard. So discussions about hypothetical weakness are hypothetical. Simon once said the khukuri was not intended for tree chopping. Bill Martino once said much of Nepal was deforested by the khuk. Some of the HI models are much tougher and better suited to tree felling than 'historical' khuks; some are not. I dont' see how we can compare historical khuks to today's, or what they did while they 'lived'.
Bill Martino also used to say that the handle was expected to be replaced every once in awhile. A loose handle is more stress on the blade, isn't it?

So, how do I compare the extreme hard use of some of my HI khuks to a historical khuk? I can't. Some people keep making an assumption the habaki is weaker, or that it can hide mistakes easier.
It's not, and it can't. You can hide a mistake with the traditional bolster. Either bolster done right is a good thing.


What do you think of what Dan said?


munk
 
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