Robert Mayo

Black Diamond Tanto

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I decided to try a tanto from an old black diamond mill file and after reading this article Water Hardening i decided to water harden it as well. I had an analog pyrometer from a kiln so i drilled a hole in the end of my forge rear door and put a piece of heavy wall chrome molly pipe inside the forge and heat treat inside the pipe. Now i know close to what the actual temp is inside the pipe. I held it at 1425 for a good 5 min after reaching temp then quenched in hot water straight from the tap. In for three seconds then out and back in at that point it blew the furnace cement off. I then put it straight into a preheated oven for three two hour tempering cycles at 400 degrees.
I am not sure how i will finish it yet but i am pleased with it so far. Thanks for looking and all the great info here!

Bob

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Looks good Robert. Can't wait to see it all finished up and mounted. Is that a little section about 2/3 rds of the way down the blade that didnt harden at the edge and a little bit at the tip (or does the hamon just drastically cut in, it almost looks like the edge hardened in the las photo, just not very deep)?

That water hardening article has made me rethink and reconsider water hardening on alloys and all highcarbons in general. Someday when I get more time I will definately have to give it a try.

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Very nice. You've got real activity in that hammon, the little white lines leading down to the edge. That's where i hope to be someday with my tanto and wakisashi.

I've read that article also. I know i've been making mistakes. I don't have a setup to heat my blades evenly and accurately to 1450 deg. Right now i work the blade back and forth trhough the forge in charcoal. That means the middle of the blade always gets the most heat as i'm going in and out of the forge, and the tip and tang end remains cooler. So by the time i get the tip or tang just past the non-magnetic them the middle is probably a little too hot. I'm still haveing a few tiny (very tiny) cracks in the blades, but they are always on the edge and in the middle where the blade get hottest. Exactly one of the causes described in that article. Also, because I travel up to my dads to use the forge at night for quenching when i'm done i drive the blade home then temper it cuz i'm too excited to wait. Not doing that anymore...

Sorry to ramble in your thread...

Lt

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Looks good Robert. Can't wait to see it all finished up and mounted. Is that a little section about 2/3 rds of the way down the blade that didnt harden at the edge and a little bit at the tip (or does the hamon just drastically cut in, it almost looks like the edge hardened in the las photo, just not very deep)?

That water hardening article has made me rethink and reconsider water hardening on alloys and all highcarbons in general. Someday when I get more time I will definately have to give it a try.


I checked with a file and those spots are hard as well i'm not sure of the cause. I do know that a long soak at the lower temp works.

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Glad ya didn't write and describe the dreaded "TINK!!"


I have quenched quite a few small blades in water but this is the first bigger blade and no tinks yet but it is inevitable that sooner or later it will happen. I would use fast oil but there are no suppliers close to me that i know of.

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Very nice. You've got real activity in that hammon, the little white lines leading down to the edge. That's where i hope to be someday with my tanto and wakisashi.

I've read that article also. I know i've been making mistakes. I don't have a setup to heat my blades evenly and accurately to 1450 deg. Right now i work the blade back and forth trhough the forge in charcoal. That means the middle of the blade always gets the most heat as i'm going in and out of the forge, and the tip and tang end remains cooler. So by the time i get the tip or tang just past the non-magnetic them the middle is probably a little too hot. I'm still haveing a few tiny (very tiny) cracks in the blades, but they are always on the edge and in the middle where the blade get hottest. Exactly one of the causes described in that article. Also, because I travel up to my dads to use the forge at night for quenching when i'm done i drive the blade home then temper it cuz i'm too excited to wait. Not doing that anymore...

Sorry to ramble in your thread...

Lt



Lt that is one thing that i always do is have the oven preheated and do not let the blade get cold. I left a nice damascus blade on my bench overnight once figuring i would temper it in the morning and when i went to the shop in the morning it was cracked almost the lenght of the blade right above the hard edge. It was an expensive lesson.

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thx for the advice, gladly taken. yeah I'm not doing that again. this whole thing is a hobby for me but I have very little time to put into it so I need to do what I can to maximize success.

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