Black Diamond Tanto

[Robert Mayo]

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

[Alberto]

Looks good!!Looking forward to further developments!!Nice hamon!!
Regards:Albert

[Robert Mayo]

Originally Posted by Alberto

Looks good!!Looking forward to further developments!!Nice hamon!!
Regards:Albert

Thanks Albert !

[ranger1]

Looks good Robert,Don't you love that violent reaction with the water quinch.

[Robert Mayo]

Thanks Andy it's not the quench it's the results i like. I would probably use oil but there are no suppliers close so use what you got if it works without the dreaded tink!

[paul savage]

Nice looking blade Bob . Did you find that working in the pipe you were able to keep a pretty consistent temperature or were you constantly tweaking the gas/air? Paul
www.savageknives.ca
savageknives@golden.net

[ranger1]

Robert, I have used peanut oil at 130deg.F. it seems to work OK but nothing gives that hamon like water.That tink can sound like a church bell.I follow Walter Sorrells method his hamons are unreal.I have also cracked a few blades.

[dave Stifle]

Robert,

Why three two hour tempering sessions? What result will that have on the blade. I'm a newbie, so just curious. I just do a one hour tempering session and wondering if I should follow your practice.

dave

[Andrew Garrett]

Dave,

I'll take a shot at answering that. My guess is that the water quench, being so violent, creates much higher stress levels in the steel than the same HT scenario with an oil quench. A single one hour temper might not be enough to temper/stress relieve the edge under those circumstances.

Did I get close?

I LOVE Black Diamond files and get them 3 for $1 at the scrap yard here in town. They are retired from Boeing and the other big plane builders here in Wichita, so I like the 'history' behind them too.

I learned here in the forums, and correct me if I'm wrong, that they are 1095 with additional carbon added.
When I use them, I clay-coat, go to critical, quench in warmed olive oil, if the refractory stays on, I stick it back in the forge, go back to critical, quench again, wire brush it, file test, a single temper at 450-475 for one hour on smaller blades, and a double temper at the same temps for longer or thinner blades.

Maybe now, I'll try a water quench and see if I get lucky, because that hamon looks way better than mine!

[pjsnell]

That hamon is very nice. Would the spot were the hamon drops down toward the edge be softer than the rest of the edge?

[ranger1]

I usually do 2 1hour sessions.on temper.I have been playing with the normalizeing process.With 1080 I usually do 3 cycles.with the O-Tanto I just finished I only did one and the steel grain really popped out it almost has the effect of a folded steel blade.I did not get that nice crystaline look that Robert achieved

[Robert Mayo]

Originally Posted by paul savage

Nice looking blade Bob . Did you find that working in the pipe you were able to keep a pretty consistent temperature or were you constantly tweaking the gas/air? Paul
www.savageknives.ca
savageknives@golden.net

Paul i found that you have to tweek it abit but once i find the proper setting on the valve it is just before it wants to start popping because of low velosity so i put steel wool in the ventury vents to make it more caberizing and fuel rich and then it will stay right on 1450. But it is hard to hold lower than 1400

Thanks Bob

[Robert Mayo]

Thanks fellows! Dave this water quenching is fairly new to me as well i just like the effect.
Andrew I think pretty well said it. Here is the link to what i read on water quenching.
http://www.dfoggknives.com/waterhardening.htm

Bob

[Robert Mayo]

Originally Posted by pjsnell

That hamon is very nice. Would the spot were the hamon drops down toward the edge be softer than the rest of the edge?

I checked it with a file and it is hard right on the edge but probably up from the edge it will be softer i think.