# Cryogenic treatment of O1 question



## SpikeC (Jun 8, 2011)

I am about to HT a blade in O1 and try a cryo treatment with dry ice and acetone. Hoss has advised me to go straight into the cryo bath from the oil quench, but I have read several sites that advise doing a temper before the cryo to minimize the possibility of stress cracking.
I respect the judgment of Hoss on this but am concerned about the seemingly consistent advice to the contrary that I have been seeing. Does anyone else have any experience with this proceedure? 
And does Hoss have any clarification on his advice?
Many thanks to any elucidation that anyone can impart on this!


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## SpikeC (Jun 8, 2011)

Ok, I found the thread where we discussed this recently. Hoss was clear about the why and how of the process, so I guess I will just grit my teeth and give it a whirl! I would't be so paranoid about this if I hadn't just spent some time carving on the blade blank!


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## RRLOVER (Jun 8, 2011)

01 is very inexpensive,you should try both ways and see what you like better.


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## SpikeC (Jun 8, 2011)

I did the HT at 1475, soaked for 5 minutes, then after quenching in fast quench oil put it into a bath of acetone and dry ice for a good 10 minutes, then into the oven at 340 for what will be 2 hours in 25 minutes more. I'm going to do another temper at the same temp for another 2hours after it cools to room temp. The blade is straight so far. 
Fun stuff! I hope there are no hidden stress fractures!


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## l r harner (Jun 8, 2011)

that should make the blade about 63-64 I like 400f temper for 62-63 hardness


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## Marko Tsourkan (Jun 8, 2011)

Do what Hoss says. You won't regret it.

M


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## SpikeC (Jun 8, 2011)

Marko Tsourkan said:


> Do what Hoss says. You won't regret it.
> 
> M


 
That's what I'm doing! I'm on the second 2 hour temper as we speak (type)!!


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## Marko Tsourkan (Jun 8, 2011)

Thumbs Up!


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## SpikeC (Jun 8, 2011)

I'm really happy with the last knife that I made, I've been using it every day and love the way it's working for me, so I'm looking forward to how this one turns out.


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## rockbox (Jun 9, 2011)

For the steel that Hoss works with, he knows as much as anyone. Hoss reads research papers while most guys on boards like myself regurgitate what some other guy has said based on an anecdote. He also has the experience to test the theories. How many people have forged tens of thousands damascus billets?


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## Marko Tsourkan (Jun 9, 2011)

Devin also knows many knife maker or/and expert on particular steels maker in US and he talks to a lot of people, so yes, his advice is GOLDEN.

M


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## watercrawl (Jun 9, 2011)

....and if you don't follow it, and it doesn't work out, he will remind you weeks later that he told you so!!


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## DevinT (Jun 9, 2011)

watercrawl said:


> ....and if you don't follow it, and it doesn't work out, he will remind you weeks later that he told you so!!



I do it with love though. 

I've made knives for 33 years. I think that is longer than any other kitchen knife maker.

There has been tons of mis information out there and lots of people have been making things up as they go and calling it the gospel of knife making. I'm just trying to save some of you the heart ache I've been through.

Love and respect

Hoss


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## SpikeC (Jun 9, 2011)

Thanks, Hoss! I followed your directions to the letter and am now ready to start grinding. The blade came out nice and straight. I would like to know how long to leave the blank in the cryo bath, though. In an effort to make sure that it was cold as it was going to get I left it in for a bit over 10 minutes. It was very cold when I fished out!
Thanks again for your advice!


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## DevinT (Jun 9, 2011)

30 minutes is standard.

Hoss


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## watercrawl (Jun 9, 2011)

DevinT said:


> I do it with love though.



And that's why I keep calling!


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