Kukri WIP - The Bone Collector

[Patrice Lemée]

First a little safety reminder even if it didn't happen while working on the Kukri. I ALWAYS leave the final sharpening for when all other work is done on a knife. I am way too clumsy to work around a razor sharp blade sticking out of the bench like that. Well I just wanted to do a little touch up on this one and of course I ever so slightly brushed up against the tip. It could have been very bad, be careful folks.

Back to work. Time to cut the shoulders on the mill. Squaring things up as best as I can.

And cutting the shoulders using a 3/16 carbide endmill. I know the pros will probably roll their eyes at my clamping setup. Gotta work on that when I find time.

Next onto the grinder to shape the tang. Following Nick Wheeler's advice I try to leave my tang as beefy as I can. Made them a little too thin in the past.

More to come...

 

[Patrice Lemée]

Now for something I haven't tried before. Since I don't grind that many knives, the plunge is still a hit or miss most of the time. There is already much work invested into that blade, especially because of the cutout, I really don't want a miss this time so I am trying to cut the plunges with a 3/16th round file. I must say it seem to be working good, so much more control. I'll let you know further down the line how I liked it.

We need to clean the inside of the cutout as best we can cause it wont be fun to do after heat treat. First step using old 220 grit belts ripped out in strips.

And then a little Foredom work. I can't remember who shared this tip on here, sorry. Using a roll pin with strips of sandpaper. Just slide it in the slit and roll tight.

The maker used some kind of sticky sandpaper but I did not have any and figured that if you roll it going the right way, the spinning motion would cause the paper to tighten up anyway. And it did, worked pretty good. You don't even need to remove the old paper much as it eventually just disintegrates leaving fresh paper exposed.

 

[Patrice Lemée]

Time for heat treat. First in the oven for a normalizing cycle.

Up to 1600F, soaking for about 5 minutes.

And then slowly cooling down. I took a pic as soon as I open the door. Why? Simply cause a foot and a half of red hot Kukri is cool. I didn't have my telephoto lens though. I am pretty sure that my eyebrows will eventually grow back.

Next step in a few days will be quenching. Stay tuned and thanks for watching.

 

[Frank Niro]

Coming along very nicely, Pat. Frank

 

[phason]

Hello Patrice, would like to ask where can i find the center scribe to mark the blade, do you make it yourself? thanks

 

[Shawn Hatcher]

I can't remember who shared this tip on here, sorry. Using a roll pin with strips of sandpaper. Just slide it in the slit and roll tight.

That's a great idea, Patrice! I'm definitely going to try that . . .

 

[Dixieblade57]

Pat, I really love this tip!:thumbup::thumbup:

Never to old to learn a new trick!

 

[elchris123]

I absolutely LOVE this WIP! Thanks much for posting it. Its great to see how much style and attitude you're putting into this blade, So many large knives have 'boring' blades and good looking handles, and it is so refreshing to see someone who believes in breaking up that large mass of steel at the end of of that often gorgeous handle. All that aside, This is a prime example of 100% functional art IMO. I cant wait to see it completed!

 

[JParisi48]

Looking good Patrice! I am dying to see the finished product, it will definitely be one a one of a kind kukri!

 

[Patrice Lemée]

Thanks for the words of encouragement guys, much appreciated. I am sure glad that the Foredom tip was useful to some of you.

Phason, I did make the scribe. You can find out more about it here:
http://www.lemeeknives.com/pages/Tutorials/tutorials_scribe_a.shtml

On a side note I think I am going to dial back the guard a little. I drew something that I liked but I want this to be usable and although it would still be in theory, it might make my friend uneasy to do so with the more artistic guard.

 

[Patrice Lemée]

Let's heat treat this baby

First some clay. Thanks to Mike Quesenberry for recommending Rutland's Refractory cement (2000 degree). This stuff is way better than the refractory cement I was using before which was grainy and watery. Can't find it in Canada though that's why it took me so long to try it.

As you can see, this is creamy, a little bit oily and much easier to apply.

I am putting roughly 1/8th of an inch on the spine and cutout. Hopefully that will do the trick. Blade clamped in the vise to dry. The cement dries pretty quick.

Meanwhile let's get the oil ready. I don't have a heated tank so I just stick this one on a small electric serpentine stove. A thermometer and a stirring stick and we slowly get the oil to it's working temp which is between 50F and 130F for Parks 50 if I remember right.

The blade now with the harden clay goes into the oven. This is 5160 so we are going for a 5 minute soak at 1525F.

Let's not forget to put on our safety gear. Thick leather apron, gloves and visor. Some folks may do it with less but I am way too clumsy. I also have a big bucked of cold water nearby as well as the mandatory fire extinguishers all over the place. I love quenching burning red steel in oil and at the same time it scares the crap out of me.

The oil has reached 130F. I remove the quench tank and put it on a couple of firebricks. It's a solid base and won't melt my floor covering. I time it so that the temperature goes back down to around 110F-120F by the time I am ready to quench.

I could not get pics of the actual quenching cause there was no way I was doing this with one hand and snapping pics with the other. All went well except that I need a bigger quenching tank. This one was too short and, as John White pointed out to me, I had part of the tang sticking out and it was the reason it smoked like crazy. Good thing I had the garage door opened and both dust extraction system going. But there was still way too much smoke and I will be going to a deeper as well as wider tank before I quench anything else.

Anyway, after about 8-9 seconds in the quench I take the blade out and put it in between the aluminum quench plates I use for stainless steels. A very nice trick to try and prevent any warping. Not that I was expecting much with this thick of a blade and the heated oil but why take a chance. Try it with thinner blade though, you will like the results. :thumbup:

Blade cooled down and cleaned with a wire brush. I did not have to scrub hard, that clay mostly popped right off except for the cutout part. Thanks again MikeQ.

More to come...

 

[P. McKinley]

Patrice - Did you put the blade into a cold oven and then heat it up for the quench process, or was the oven already heated to temp?

I've also been looking for Rutland cement, as was recommended several makes. Did you get it through the interwebs?

eta: That block of Rosewood on your bench.... it looks familiar.
Thanks,
-Peter

 

[9blades]

Patrice awesome wip cool kukri and smart trick with the foredom!
And if you make another knife with the cutouts I think it be cool if you rounded them like pillars just my $0.02.
Can't wait to see the finished kukri!

 

[Patrice Lemée]

Peter, I put the blade in a cold oven and ramped up to temp as fast as the oven will go. I want to say it took about 45 minutes to reach temp but I can't say for sure. I seem to remember that it is best to do it this way compared to an already hot oven but I am no heat treating expert.
Sadly I got the cement at an Ace hardware store in the states.
I did not send the wood you sent me to be stabilized yet so this is not rosewood but stabilized Redwood burl. That reminds me I should get all the pieces I need to have stabilized together to send off. Thanks.

9blades, the pillar idea was in the cards at the beginning of the designing process but got discarded when I went with the bone theme. I will definitely keep it in mind for another project. Great minds as they say.

Thanks for the good words.

 

[cbr900son]

I never thought of the quench plates after to keep straight.

 

[quint]

Great idea on the plates. Curious I guess since you get temp down quick enough in that 8-9 seconds then it wont affect hardness overall.

One thing I could be wrong but thought it was best to get oven up to temp then put blade in due to the temperature spikes from the elements getting the oven up to temperature. Cant remember who it was that was showing the temperature spikes in the oven but there is a good thread about it somewhere around here.

 

[Patrice Lemée]

Thanks quint, I'll try to find more info on that.

Time to finish grinding the blade. A good trick is using the disk grinder from time to time to check that everything is flat. It is easy to round over the grind on the KMG with flat platen, well for me anyway. Got the tip about the disk grinder from Nick Wheeler with about a zillion others of course. :thumbup:
I do have to change disk location though cause it is kind of close to the KMG on the right side, for this size blade anyway. Still using 60 grit on the KMG and 120 on the disk at this point.

Since it's been a long day and I am pooped, finish grinding is not a good idea so let's take a break. One thing I can do is to draw the tang a bit. Again I use Nick's technique. I didn't have a deep enough bucket so I used a large ammo can. Good thing is I can't melt it with the torch. Bad thing is that I have to angle the blade and it is a little awkward. Big bucket added to the “To Buy” list. I also need an OA rig eventually, this propane setup is barely hot enough.

I “walk” the temper line up towards the blade, adjusting with torch and water to make sure I don't run into the cutting edge. I try to move it to right past the shoulder about 1/8th” up the ricasso. Not sure it's the exact way to do it so if somebody with more experience reads this, please correct me if I am wrong.

Now I have been eyeballing the grind for a while so I need to scribe some lines to keep things symmetrical.

Finally no pics but I put the temporary handle back on and took a few swings at a 2X4 to get a feel for balance. Of course it didn't cut but I can see how this type of knife is a mean chopper. I did find that there was a little too much weight still in the 4”-5” above the ricasso. A little less and it would feel weighted a little more towards the sweet spot. I don't want to thin the knife so I will have to fullers of some kind. I only wish the steel was not already hardened. Total weight stand at 22 5/8oz so we are on the right track for a final weight around 20oz.

Thanks for watching

 

[Dixieblade57]

:thumbup:Looking good Pat!

 

[Eric Kidwell]

Looks great Patrice. Work safe.

 

[Patrice Lemée]

Thanks for the good words guys and following along.

Ok, let's see what we can do about the weight. A fuller it is. Starting with making a groove, using a carbide burr, roughly where I think the fuller should go.

Now we switch to small sanding drums (still using the Foredom) and make this into a proper fuller.
On a side note, I have to see about reversing the Foredom. Never thought I'd need it but the way it is turning now, I am grinding steel right into my face. Even with the Airshield I still get a nose full of steel dust so that means I breath some of it and that is no good.
Anyway here is the small fuller.

Not happy with that. Much too defined. So back to larger sanding drums and it is finally starting to take shape. But it is still not quite what I am after.

So as if I had not enough time invested in this blade yet I thought, why not add 4 plunges and about 4” of a dagger grind. Ok I did not think of it that way at the time but that is what it meant.
So back to the KMG with the 10” wheel. Was a bit nerve wracking but I finally found something I like. It also took some weight off, we are around 21.25oz, and you can feel the weight more behind the belly. I still have to do something about the straight plunge in the middle of the blade but I am very happy with the overall result.

Wish I thought of that before I spent all that time blowing dust up my nostrils. Between the Foredom work and dipping the blade every pass or so to keep it cool, I must have spent about 3 hours on that fuller I just ground away. That's why I would love to be able to have an exact blueprint when I start. Oh well...

I will probably move on to the handle next. It will give me a break from working on the blade so I can come back to it a little refreshed.

Thanks for looking.