Hot Dog in a Bun Weld

Sam Salvati

Sam Salvati

Joined
Aug 6, 2007
Messages
5,060
This is a technique the Japanese use for kitchen knives and other tools, It has a Japanese name but I call it the hot dog in a bun weld for obvious reasons. I have obsessed over it for about a year, and think i have a good grasp on it now.

As shown it is a hot dog of high carbon steel, laminated on 3 sides by a bun of mild steel.

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I like the term hot dog in a bun, lol. What are the reasons why you chose to try the hot dog?

Cool stuff Sam!
 
For the readers who aren't familiar with Japanese forging arts - AKA kitae:

In centuries past steel was a very precious and hard to make thing. When doing a smelt in the Japanese tartara, the final bloom had everything from cast iron (3% and higher C) to pure iron (0% C). Some of the product was steel in the .50 to 1.20% carbon content range. A skilled smith would smash the bloom, separate the usable chunks, and they would be placed in groups by carbon content. Once properly sorted, they were forged into bars of iron and bars of steel. The steel was the most precious because of its rareness and its edge abilities. Unfortunately, the steel was also brittle. The iron was tough, bendable, and plentiful ( compared to steel). They would make stacks of the different metals and weld them into billets with many patterns. The good steel was in a place in the stack to make an edge. The bulk of the blade was various arrangements of iron and low grade steel. Depending on the use and type of blade or tool to be made, the edge steel was sometimes on the outside, and sometimes on the inside of the soft iron.

The "hot dog in a bun" method - wariba - was the simplest to do and made the most blade from the least steel. Some billets had less than 10% of the blade being steel. Knives made from these billets had to be carefully forged to shape to expose the hard steel and then carefully ground and sharpened to avoid grinding it all away. I think the term means something like "ratio of edge".
 
And guys in the other places in the world did similar things [but without the weird words ] . Still today we use the idea and for the same reasons. Like Sam's special hot dogs in a bun !!
 
I have a question: with carbon migration, wouldn't you need to start with 2% carbon or more to get a hard enough edge?
 
Thanks everyone!!!

Don Nguyen said:
I like the term hot dog in a bun, lol. What are the reasons why you chose to try the hot dog?

Cool stuff Sam!
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Thanks Don! I do too, this is America dangit~!

mete said:
And guys in the other places in the world did similar things [but without the weird words ] . Still today we use the idea and for the same reasons. Like Sam's special hot dogs in a bun !!
Click to expand...

Yes! this is prevalent in one form or another all over!

Salem Straub said:
Now I want to see one with high layer pattern weld kawagane.
Click to expand...

yeah...this could happen in the future......
 
Willie71 said:
I have a question: with carbon migration, wouldn't you need to start with 2% carbon or more to get a hard enough edge?
Click to expand...

There is the potential for carbon migration from the high carbon to the low carbon. However carbon migrates as a function of time and temp, also it does not go that far (maybe a few thousands) in each direction. So the best way to do this is to get it to welding heat, make the weld and then lower the forging temp into the normal forging temps for the steel and forge it out relatively quickly. If someone is usingn 1018 and high carbon (say 1095) to make high layer damascus, then they will have a steel that is like 1060, due to migration in hundreds of layers. I dont know if a steel with 2% carbon would even be forgeable. Maybe someone else could shed some light on that.

This is also an awesome method for forging kitchen knives because tall thin knives almost always warp during hardening(for me anyway). With the soft outer layer, you can actually cold straighten the warps and they stay. No more shims and a ton of tempering to get them straight.
 
JMJones said:
There is the potential for carbon migration from the high carbon to the low carbon. However carbon migrates as a function of time and temp, also it does not go that far (maybe a few thousands) in each direction. So the best way to do this is to get it to welding heat, make the weld and then lower the forging temp into the normal forging temps for the steel and forge it out relatively quickly. If someone is usingn 1018 and high carbon (say 1095) to make high layer damascus, then they will have a steel that is like 1060, due to migration in hundreds of layers. I dont know if a steel with 2% carbon would even be forgeable. Maybe someone else could shed some light on that.

This is also an awesome method for forging kitchen knives because tall thin knives almost always warp during hardening(for me anyway). With the soft outer layer, you can actually cold straighten the warps and they stay. No more shims and a ton of tempering to get them straight.
Click to expand...

For an experienced smith this would work well. For me, who has only forged a handful of blades, its not going to work well. Thanx :thumbup: I would need too many heats with my lack of experience.
 
Damn....

Now I want a Hot Dog.

Nice work Sam
 
Power hammer is ideal here, or someone with a sledge that knows what they are doing. Could always tuck in a bit of pure nickel or 15n20 like a slice of cheese wrapped around the hot dog. Nickel makes for a migration barrier.

Haha Adam!
 
Please use the term Diffusion not Migration !!
Sam you should asks those of us who know cooking to give you hints how to garnish your hot dog with mustard , sour kraut, etc.
 
mete said:
Please use the term Diffusion not Migration !!
Sam you should asks those of us who know cooking to give you hints how to garnish your hot dog with mustard , sour kraut, etc.
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I used diffusion previously, and was corrected to use the term migration. Oh well. Diffusion it is. :thumbup:
 
Sam Salvati said:
Power hammer is ideal here, or someone with a sledge that knows what they are doing. Could always tuck in a bit of pure nickel or 15n20 like a slice of cheese wrapped around the hot dog. Nickel makes for a migration barrier.

Haha Adam!
Click to expand...

Chili cheese dog san mai. Make it happen.
 
mete said:
Please use the term Diffusion not Migration !!
Sam you should asks those of us who know cooking to give you hints how to garnish your hot dog with mustard , sour kraut, etc.
Click to expand...

Haha! i am a squeeze cheese aficionado with maybe some chili
 
Sammi,
Wariba billets would be quite popular.

Right now those who want that type of billet have to get them from Germany....of make their own. The Hitachi honsanmai steel is about $50 for a 15" bar.
 
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