Zak-e-toh from the "Pile of Steel"

[ndoghouse]

I was playing around with the pile of burned steel again and made what Im calling the Zak-e-toh because it looks like a big exacto knife It has been on the table by my side and has become a much more useful tool than I ever imagined so i wanted to tell someone about it. It is well suited for trimming flesh and picking thorns, splinters and other minor surgical procedures which is almost a daily occurrence for me and my self inflicted wounds. This is my second ever attempt at differential tempering. No its not a Khukuri but Its a doggone useful tool It has been finished on a japanese waterstone to 8000 grit and is convex ground. It is shaving sharp! It also has a point much like a new exacto blade but a bit thicker for durability reasons.

The blade was quenched then tempered with a propane torch at the spine to spring temper (purple) leaving the edge at straw color for proper edge hardness. This is not easy to do! Hats off to anyone who has mastered this!

The tip was very springy and returned back to position like its supposed to so it must have worked.

This was the plan: Curl the handle to wrap around the finger so it wouldnt slip or twist around during "surgery".

Then cut some finger knurls for a bit more control. I know they make a special file for this and have seen them do it making straight razors but i thought id try it with a triangle file. Looked great for a near blind man till I zoomed the pics? Oh well it works! I clamped a hacksaw blade along the spine to use for a guide then once I got started I could unclamp it and file deeper. Sort of worked.

I saw a primitive sheath one time that used staples in a wooden sheath that left the blade exposed and thought that was really cool so this is my modern rendition to that idea using magnet wire and an oak root burl I found buried in the yard. This is what I ended up with. I figured I could bend the wires inward to retain the blade if it was loose and it did work well.

I started out with pulling a loop in the wire and winding a coil from there. I cut grooves in the back to bury the wire in and continued wrapping until I got to the end.

Once I got to the end I stripped and tinned the wire and bent it over and melted a solder ball in the hole to retain it. File it off and done deal.
I did rub the wood down before assembly with boiled linseed oil. I really want to try this with a larger sheath and knife. This was just practice run so I dont screw up something bigger. It was fun and learned a few things so hope someone likes it! Enjoy!

 

[J W Bensinger]

Very cool! Differential tempering (as opposed to hardening) is indeed tricksy. I still use triangular files for thumb grooves to this day. The 1/4" ones are very precise.

 

[Jens Schuetz]

Glad you like this kind of sheath and actually made one!! I saw it once in a movie on Taiwanese native knives.
How did you shape the blade and tang? Cold or in a forge?
Looks very useful and cute at the same time!

 

[ndoghouse]

I heated it and curled it hot. Yep its cute but it fits so snug in the hand i wouldnt want to be attacked by one thats for sure. You wouldnt even know your cut until something fell off.

Glad you like this kind of sheath and actually made one!! I saw it once in a movie on Taiwanese native knives.
How did you shape the blade and tang? Cold or in a forge?
Looks very useful and cute at the same time!

I dont have a forge yet so im unable to heat a large knife. Ive been using the woodstove. I form a pocket of coals under the wood really hot and just before i pull the blade out I turn the blade edge up and heat the edge with a torch while still in the fire to get the edge hotter. Then i pull it out and quench it next to the stove. Since im doing this in my living room im using peanut oil so it dont stink up the place. I quenched a few blades today for the next project. A Santuko, and another JA Henkel blade at the same time and they are bent so looks like I got to redo them.

 

[Gehazi]

very very cool ndog, very purty

 

[pugs75]

That looks really cool. The first pic made it look huge but boy is it a nice working size. I can think of tons of stuff to use it for, has a lot of versatility to for sure. I love the larger blades but you always need one like that for the smaller work. That sheath is really nice I love the open style, you see alot of older Philippine blades with this type of sheath, You certainly are a craftsmen for sure. Great job brother

 

[J W Bensinger]

Ndog- stick with vegetable oil even when you build a shop. I've been using canola oil for almost 25 years. Quenches fast, doesn't flare unless you're quenching something really big (like a hammerhead) and doesn't give you cancer like motor oil (especially used motor oil). Only reason I never tried peanut is I neede six gallons or so for swords...

 

[Bawanna]

How sweet it is. That's awesome. I'd love to hold that thing. Now in addition to you running around barefoot I gotta worry about ya playing with red hot stuff.

Nice done.

 

[ndoghouse]

Ndog- stick with vegetable oil even when you build a shop. I've been using canola oil for almost 25 years. Quenches fast, doesn't flare unless you're quenching something really big (like a hammerhead) and doesn't give you cancer like motor oil (especially used motor oil). Only reason I never tried peanut is I neede six gallons or so for swords...

AH! Thanks JW. Thats a consideration I hadnt even thought of. Dont need any more cancer in my family thats for sure.

While your here I have a question for ya. When you get a warped blade after quenching. Is it recommended to throw it back in the fire and straighten it then requench it or would it be possible to straighten it after differential tempering since the spine is softer then. Its only warped about a millimeter or less. its an even warp all the way across. It was straight when I put it in but maybe i wasnt careful enough and pushed a log on it or something? Im pretty sure the right answer is to put it back in the fire but there is no fire today so was just curious what you might be able to get a way with. It wont bend now because it is only quenched and id probably break it. Nicholson file skates across so I know its hard. Once i dont feel so stupid ill slip into the "hammer and tongs" forum but for now we are fortunate to have a brother with your knowledge right here with the Khuks forum:thumbup: How khul is that!

 

[J W Bensinger]

What I do- and there is room for things to go pear-shaped here- is quench, let it cool to "too hot to touch" in the oil, then pull it and wipe the oil off quickly. Check for warp, and have a solid piece of wood to set it on- you can then straighten with careful hammer hits. (You have a limited time window here, mind). If you don't want to potentially have to grind out hammermarks, either use a hardwood mallet or put a piece of leather over the blade.
You can also straighten a bit when tempering-while it's hot from tempering you can move it a little bit.
If it's water quenched method #1 is disasterous.
One way to minimize warp is to normalize after grinding: heat the blade to nonmagnetic and let it cool slowly in air- then proceed with hardening. This takes out some of the stress that causes warpage.

 

[ndoghouse]

Makes perfect sense. Thank you sir! I just quenched a few other blades today and the thicker ones are definitely easier to get a uniform temper. One was a custom damascus staghorn skinner. Was a cool knife with a nice crown, brass bolster and guard. Ill show some pics as I get further along.

 

[greenwoods]

I like the shape, size, finger jimping, heat treat, curled handle and especially the sheath. That little spiral at the sheath tip and the copper is good looking. I always prefer copper to brass and other metals.

Thanks for sharing.

Mark

 

[blue lander]

Very snazzy looking little knife and sheath. Can't wait to see what you come up with next!

 

[ndoghouse]

What I do- and there is room for things to go pear-shaped here- is quench, let it cool to "too hot to touch" in the oil, then pull it and wipe the oil off quickly. Check for warp, and have a solid piece of wood to set it on- you can then straighten with careful hammer hits. (You have a limited time window here, mind). If you don't want to potentially have to grind out hammermarks, either use a hardwood mallet or put a piece of leather over the blade.
You can also straighten a bit when tempering-while it's hot from tempering you can move it a little bit.
If it's water quenched method #1 is disasterous.
One way to minimize warp is to normalize after grinding: heat the blade to nonmagnetic and let it cool slowly in air- then proceed with hardening. This takes out some of the stress that causes warpage.

Thanks JW. I tried straightening after tempering but it was way too stubborn. Your right about the "window". I bent it every which way but straight Last night I put it back in the fire and annealed it again completely then flattened it out. I normalized it again and got it to stay straight after cooling to room temp so figured it was ok. Then back to the fire. I also moved the blade back and forth during final heating to spread any hot spots more evenly across the blade while torching the edge and then quenched. Came out great! Thanks again! Time to temper. I dont have any of that thermal mask yet but used a bed of wet sand to dip the edge in while heating the spine. It seemed to allow a more even heat distribution across the thinner blades edge. Any problems with that? It seemed to work? Ill post a few pic when I get half a chance.