Field Report on 15 inch AK and Uncle Bill

C

Coonskinner

Joined
Mar 28, 2001
Messages
2,491
I bought a 15 inch AK some time back when Uncle Bill ran a special on four "Almost Blems." I couldn't find anything that looked like a blemish to me when I examined the khuk. It looked great.

I took it down on the creek with me one evening when my son and I were going to do a little plinking, and did some chopping on a seasoned log. To my surprise, the edge took a pretty severe fold, an obvious case of a too soft blade.

At the time, I didn't post a report on the failure, because there had been several failures posted, and Uncle Bill was seeming pretty stressed out about it. I felt like we didn't need any more negative stuff posted at the time. I just sent the Khuk to Art Swyhart for repair and rehardening.

This week I got an e-mail from Art that my AK didn't survive the repair. When he tested it by chopping into a piece of Osage Orange, it blew a large chunk out of the blade. He said Uncle Bill was sending me a replacement right away.

I wrote to Uncle Bill to thank him for this honoring of the guarantee, and he said to post away about the failed khukuri. So here it is.

But the main point I wanted to make is this--I bought a khuk at a reduced price, one he called "Almost a Blem." When the knife didn't work out, he promptly put another in the mail, and didn't ask me to make up the price differential between the one I bought and the one that is on the way.

I recognize that HI lost money on this deal. But I guarantee that as soon as I rake a few more pesos together, I'm going to buy another Khukuri or two to help make up the difference.

Bottom line? Bill Martino is an honorable man and a pleasure to do business with. My hat is off, Sir.
 
Thanks for report and for kind words.

I try my best do do things right based on the Golden Rule principle. I might not always get it done as I should but I do give it my best shot.

Thanks again.
 
When I called Uncle Bill and sheepishly told him what I had done, his instant response was that he would send out a new khuk. His first priority is always to satisfy his customers. I wish all businesses were run this way.
Made the egg on my face a little easier to deal with, too.
 
If there is a man among us who never made a mistake and has won'em all, please take a step forward. I'm staying right where I am.
 
Art deserves a big "Thank You" for his work on repairing and rehardening the ones that slipped through not quite up to speed.

I don't, or at least haven't, posted a lot on this forum, but I read it every day, and have been very impressed by the feeling of community and goodwill. I'm not exactly an internet afficionado, but I doubt if anything quite like this forum exists anywhere else on the net.

I'm glad to be hanging around.
 
Originally posted by Coonskinner

Bottom line? Bill Martino is an honorable man and a pleasure to do business with. My hat is off, Sir.
Click to expand...

Art deserves a big "Thank You" for his work on repairing and rehardening the ones that slipped through not quite up to speed.
Click to expand...

I often choose not to add my opinions in many of the discussions here simply because there always seems to be another forumite around who states exactly what I would have said if only I were a bit more articulate, and leaves me with little more to add than, "Me too!"

But this is one where I just have to pipe up and say, "Me too!" :D
 
Art, in the interests of me understanding metal better, why would you feel sheepish about the Khuk blowing a hole out its edge? I'm guessing too hard. If you don't mind teaching a little, what happened exactly?


munk
 
I'll stick this in and Art can comment as he chooses.

First, the fault may lie in the original manufacture.

Second, Art is using a torch to heat the blade and from experience I know it's much harder to control and ditribute the heat with a torch than a forge. It is very easy to get an inch of blade harder than you want using a torch and water quench. Using a torch I was successful 75% of the time and happy with that. Art is doing better than this.
 
Thanks, Uncle Bill.
The blade failed about an inch behind the point on a 15" AK.
The heating and hardening went well but the water was colder than usual; the blade was hard[/] from the sweet spot to the tip. This should have been a warning to me to check very carefully for any stress cracks from the shock of the water on hot steel.
Then,when I tempered the tip to make it slightly softer I didn't bring the soft area back far enough. I thought this part of the blade would not get as much shock as the sweet spot.
Boy, was I wrong.
This combination of cold water and insufficient tempering is probably the cause of the blade failure.
In another thread, Cliff Stamp writes about the folly of edges that are too hard for the shock they're expected to endure.
This failure just reinforces his opinion.
 
The only way you can avoid making a mistake is not to do anything. You're shooting 85 or 90 percent doing strange things to strange knives and that's plenty good enough for me.
 
How do you decide how cold the water should be?

Forge= whole steel hot, torch =parts of steel hot. This right?

The heating and hardening went well but the water was colder than usual; the blade was hard[/] from the sweet spot to the tip. This should have been a warning to me to check very carefully for any stress cracks from the shock of the water on hot steel.
Then,when I tempered the tip to make it slightly softer I didn't bring the soft area back far enough. I thought this part of the blade would not get as much shock as the sweet spot.
Boy, was I wrong. >>>>

So in breaking one, you learn more how it was put together, where the Kami's wanted hard and where softer?

This is interesting.
Thank you.

munk
 
Munk,
Large blades usually have a softer tip because that's the part used in digging or prying. The sweet spot is harder because that's where the edge will meet hard material while chopping. The area between the two is a transition from hard to soft and the exact hardness at any spot is a matter of judgment and skill.
Most spring steels contain small amounts of chromium and manganese. Because of these alloying elements, spring steels do not like to be quenched in water; they were designed to be quenched in oil. The kamis have learned to pour controlled amounts of water onto the blade to lessen the thermal shock. You can also reduce the shock by using warm water. If a blade the size of a khukuri were heated to hardening temperature and plunged into cold water it would shatter into three or four pieces within 10 seconds.
The kamis have learned all this through centuries of trial and error.
It's amazing.
 
I won't bug you with any more questions. Perhaps within the forum there are metalurgy threads-I know there are.

It's funny spring steel doesn't like this rapid change with water; isn't that what spring steel handles best when it is finished and used in tools? Paradox.

oh hell...one more question; why don't the Kami's use oil if spring steel likes oil better? Because no oil was available?

munk
 
I think khukuris were first made before there were special spring steels available to the kamis. The earlier, simpler steels would likely have responded well to water.
If you want to quench only the edge, you have to have a container that will hold only the edge with most of the blade and spine out of the oil. Curved blades were quenched by chopping into a gourd in Java and Malaysia; nobody else seems to have had containers shaped for this quenching.
Much easier just to pour the quenchant on the blade, and water is a whole lot cleaner than spilled oil. Oil may or may not have been available, but in a poor country may have been too valuable to use.
So there are probably several reasons the kamis learned to work with water instead of oil.
 
Anglo-Saxon supposedly used honey for quenching...sounds rather expensive to me.

--B.
 
Two thoughts, based on recent research:
1) a brine solution would not cool the steel as quickly as H2O (provide less thermal shock), an still be less messy that oil.

2) I recently read that synthetic transmission fluid was developed to meet the increased demand for sperm whale oil as a lubricant in automobiles. Whoda thunk it?

Pat
 
Water was the quenching medium for 2500 years or so. It was used in Nepal "since the beginning" and a kami's skill is largely passed down from one generation to the next. The hardening of the blade is really an art rather than a skill.

Bura was giving me a lesson in hardening a couple of years ago --"setting the pine" they call it. Pine = hardness.

Bura lectured as he did the work.

"Color is very important. See this color? The blade is not hot enough. See this color? The blade is too hot. See this color? It is just right. See the color at the tip? See the color at the cho? These all must be just right before you start to pour."

When the blade color was just right he began to pour from his pitcher.

"You cannot pour too fast and you cannot pour too slow. You must pour just the right amount at just the right speed. Watch the blade change color. You will see red, purple, green, in various shades and then black. If you do not see the color change seven times you have missed and must begin again. See it has changed three times already. There, again. And again. Again, and now it is black. It is finished and the blade pine is just where we want it to be. It is very hard here (pointing to the chopping area) and not as hard here and here (tip and bottom of blade). This knife is perfect."

I took a file to check the blade and Bura chuckled. "You are wasting your time."

And I was.
 
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