Combating Chipping?

Steely_Gunz

Got the Khukuri fevah
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May 9, 2002
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Ok, I've run into a bit of problem with my Trisul, and it's making me feel like a n00b all over again:D
I scored a Trisul from the DOTD a couple weeks ago, and I love it:) Very well made weapon. When I got it was typical HI with excellent fit and finish, but with a tad over-buffed edge. No problem! I'm a sharpening pro like many of y'all. I take it to a butcher's steel, then to some sand paper, then to some leather. The first 1.5" of the tip split my thumb when I checked the edge (ouchie!:eek: ). Likewise, from the guard up and 4 or 5" it will shave easily. I didn't convex this all the way out because it's not a chopper. I wanted a bev on the edge to give it strength, but didn't need a full on chopping edge. However, the edge right around where the sweet spot would be on a khuk would not sharpen for anything. I finally had to take a diamond file to it to rough the shape before finishing it with my standard method. It didn't take a great edge, but it was good enough. The steel was REALLY hard there. No biggie, how often am I going to use this knife for anything besides cutting a few pool noodles and packing it in my bag for a little SD back up?

Here's the problem I ran into. Friday, before I left work I noticed a chip in the edge right in that really hard sweet spot. Nothing major, about the size of a small fingernail clipping. It could be sharpened out, but i would have to bring in my stones. No biggie, but it was going to have to wait until Monday. I come into the office a bit early today sipping on my coffee with stones in hand and unsheath the Trisul. I'll be darned if ANOTHER chip hasn't developed while it was just sitting there for 2 days!:eek: Just like the other one and in the same area. Here's my theory: I know the edge is super hard. I mean SUPER hard there. My office is not an EXTREME place, but it temp does vary quite a bit from 60 at night to 75 during the day, and it is humid with two spas running 24/7. This is never enough to cause any real problems for any other knives and khuks living at my office, but could the thin edge that is overly hard be affected by the flux in temp and humidity? That said, this place really isn't that different from a house in this area during the summer months. It just stays a little more humid than most due to the spas, and they are ozonated so the chemicals in them is probably less than what is in your tap water. No rust of any kind has developed, and it has been in it's sheath since 4:30 Friday until 8:15 Monday. The edge just keeps chipping pretty much on its own. The only thing that this knife has cut is two or three passes through a foam pool noodle...and my thumb;)

I can fix it with stones and sandpaper making the edge more convex, but I kind of hate to fatten up the edge of knife designed with such a thin edge in mind. What are my options oh sharpening gurus:)? Has anyone else had this problem before. I want to make it clear that I don't fault HI. The knife is great beside the phantom chipping. I have several pieces by Sher, and have found his work to be some of the most dependable that I own. I don't think it's a serious flaw of any kind, but I also know that the knife was never used for anything outside of it's design...if you can call practice cuts into generic Nerf part of it's cutting design;) I know that I will probably never need this knife in a SHTF situation, but I would like the stop the chipping without having to take off a ton of steel.

Thanks in advance!
Jake
 
I'll be listening to this thread, Jake, as I've never heard of this and hope to learn something.
If the edge is so hard it is brittle than it is not right. I think the edge is going to need to be reprofiled in that area.
I don't like this because what happens if you use the blade and a chip comes off into your eye? I want to hear some expert advice on this one, and Yangdu may have to help you out.


munk
 
Thanks for your concern, Munk. Much appreciated. I just did a quick Muriatic acid dip to bring out the temper. It's an extreme etching agent, but it works fast and shows the lines well on a polished steel blade. I found that Sher did a really good job of pouring his kettle. The sweet spot is almost the full length of the edge with an area of about 4-5" that hardened nearly halfway up the width of the blade, then tapers again, and finally the last 1/2-3/4" of the tip is fully hardened. He did a really good job in that regard.
However, if it is overly hard, then that means no amount of grinding short of making it an axe-like edge is going to keep this very thin edge from chipping.
One thing I did notice etching this blade was the the temper line just POPPED as soon as I applied the acid. I've never had that quick of a display. I have no idea if that has to do with blade hardness or not. I wish I had my camera here to take a pic, but the Mrs. has it today.
I've sharpened the Trisul a little more with a butcher's steel to hog off any metal that might be hanging around one of the chips.

What do you guys think about donning my leather jacket, a set of goggles, and taking the knife to a piece of hardened ash? Would that abuse the knife too much, or should it be done to make sure the chips were just flukes? Do you think that would cause any more weakened edge to fail, or would I be in danger of destroying the knife? I know it's not a chopper, but I want to make sure this Trisul is going to be safe for my great grand kids to use:)

Any ideas would be greatly appreciated.

Jake
 
Jake, I would not take the blade to a peice of hardened ash. I've sent a link of this thread to Yangdu, and I'm hoping some expert technical advice shows up here before you do anything. Let's wait a little.


munk
 
I agree, Munk. I didn't make it clear that it was hypothetical on my part to do so. Before I do anything, I want to hear what the experst say. After a little fiddling the blade is fully sharp besides the two chips and no more chips have cropped up. I'm more curious than anything, really:) I wasn't planning on etching the blade, but I was really impressed with the amount of thought Sher put into it:) Just to make sure that all the new folks out there know, this is not a big deal at all. I don't want to cause HI or Yangdu any trouble. I'm just curious for discusions sake.

Jake
 
Hello Jake,

Send it back to Himalayan Imports for replacement.

Himalayan Imports
3495 Lakeside Drive PMB 69
Reno, NV 89509
 
If the "sweet spot" is too hard to file, it's too hard. I'd love to try the judicious application of a torch to the spine to try and temper it a little. Might work, might not. Be fun to try.

Steve
 
Yangdu said:
Hello Jake,

Send it back to Himalayan Imports for replacement.

Himalayan Imports
3495 Lakeside Drive PMB 69
Reno, NV 89509

Thank you, Yangdu. E-mail sent. Once again, I don't think there is anything "wrong" with this knife. I was more curious than anything. I think it would still work just fine if I were going to use it just for poking things. However, I need a blade to stand up to slicing and minimal chopping. Really cool knife, though:) I hate to see it go.

Jake
 
Steely_Gunz said:
Thank you, Yangdu. E-mail sent. Once again, I don't think there is anything "wrong" with this knife. I was more curious than anything. I think it would still work just fine if I were going to use it just for poking things. However, I need a blade to stand up to slicing and minimal chopping. Really cool knife, though:) I hate to see it go.

Jake

Can I have it ? I would like to pay shark price plus shipping. :)
 
ferguson said:
If the "sweet spot" is too hard to file, it's too hard. I'd love to try the judicious application of a torch to the spine to try and temper it a little. Might work, might not. Be fun to try.

Steve


I agree, sounds like the blade would need to be tempered in order to bring down the hardness in the sweet spot... Too bad it has to go back. Wonder what Yangdu does with the returns? Might make a nice project for Dan Koster or some other forumite who has the skill to tackle it!
 
Yangdu said:
Hello Jake,

Send it back to Himalayan Imports for replacement.

Himalayan Imports
3495 Lakeside Drive PMB 69
Reno, NV 89509

Now that's the kind of "expert advice" one likes to know will come from the product source!
One "maybe" has some doubt, "maybe" one is not perfectly happy because of this or that,............. and what does the source say.................. "Send it back, we will replace it".



That's simply awesome :thumbup:
 
That's simply awesome >>>>>>> JJ

I'm content you are pleased, Jimmy. We have been telling you this for some time, that HI customer service is second to none.



munk
 
Yes, I have seen a lot of positives concerning HI's customer service, though it's always a pleasure to actually see it in progress (recently Shao, and now Steely) ;)
 
Jake,

I've been holding back posting this because other REAL DEAL makers would know more and have better vocabulary. Also I'm not sure how much of this applies to khuks and the kamis forging technique. Dan would.

Anyway here goes. Generally, when the steel gets pounded it generates internal stresses. After pounding it is heated and allowed to cool slowly several times with the point facing north. This is called normalizing and relaxes the stresses in the steel. Then it is ground to shape, heat treated, and finish ground. I wonder if its these type of stresses playing a factor here.

All speculation, I don't know jack, don't listen to me I rode the short bus. What do you think Dan, could internal stresses cause this phenomenon?

Also, what does it matter with the kind of service Yangdu gives?
 
olpappy said:
I agree, sounds like the blade would need to be tempered in order to bring down the hardness in the sweet spot... Too bad it has to go back. Wonder what Yangdu does with the returns? Might make a nice project for Dan Koster or some other forumite who has the skill to tackle it!

do you mean "anneal some?" it's already been tempered...

someone with the skill could anneal it, and then retemper it, though not perhaps differentially as the original, as the kettle technique is somewhat a unique skill to the kamis; clay is for the japanese, and ...

the old style farm technique was the heat it until a certain point, the oil quench, and you're good enough. it IS a stabby stabber, with some edge after all, not a chopper.

bladite
 
Bladite said:
do you mean "anneal some?" it's already been tempered...


bladite

No, we both meant temper. :) Tempering is the process of heating to a temperature lower than the hardening temperature. This reduces the hardness, and increases toughness. Annealing is the process of completely softening the blade.

We would be differentially tempering by heating the spine of the blade and watching the colors of the polished steel change to a light straw color, indicating proper hardess.

When the kamis harden the blade by pouring water on the edge (hardening), the residual heat in the spine conducts back to the edge, softening it some (tempering).

Many folks mistakenly use the term tempering to mean the entire heat treating process.

Steve

Andy, it probably is internal stress causing the chipping. Just too hard.

Here's a good overview of heat treating
http://www.dfoggknives.com/hardening.htm
 
Thanks so much for all your help guys. I have spoken with Yangdu, and this Trisul is heading back to Reno to be replaced. I was hoping that i could salvage the knife, but just polishing out the etch broke off some more chips in the same area. That's a bummer, but these things happen. handmade stuff always has a chance of that. That's just fine with me:):thumbup:

Thanks again for your help, and thanks again to Yangdu for such fast customer service:) Just another reason why HI will always get the lion's share of spendin' money:)

Jake
 
Steely, my guess is that the area that is chipping out is full hard. If you leave a fully hardened, untempered, blade laying around it will sometimes snap completely in half.

Aproy, I don't know if the kamis normalize their blades after they are done forging them. We might be able to ask Yangdu if she knows, just from watching the process.

Somewhat off topic, I am considering bisecting my kami with no name Kobra to investigate how deep the hardening goes ( this one was accidentally beat up by me years ago ~ note to self, do NOT chop on seasoned cow femurs with kukri). I really think that on some of these blades the hardened section is like a sheath, and does not penetrate fully to the core. I was stunned by the way that I was able to distort the edge and then beat it back into shape without it snapping out chunks. If this is something you all would like to see I will do it. I would need someone to post the pics for me though.
 
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