San Mai BAC WIP

Sorry for the sideways pic. Photobucket was not cooperating:thumbdn:

Darcy
 
Dang that sucks. Is the blade too thick to get the 15N20 to harden at the spine? What did you quench in?
 
Grind the faces away to kitchen knife thin and re heat treat. The hardened core will have more influence if the outer layers are thinner.
 
That's not a bad idea.......might give that a shot. It will not be the blade I intended, but might still make some sort of cutter. Design modification to the rescue??:D
I quenched in warm veggie oil. I ground the scale off the spine and it would skate a file, but maybe not further in between the wrought iron cladding.

Darcy
 


I cut my billet in half, ground clean on one, and then tack welded them to a 1/4" bar of 1084. Using a thicker core of blade steel should make the end knife stiffer. Sadly though it will no longer be San Mai as it will have 7 layers:o

Now I have another billet that needs forge welded and drawn out....
 
Bruce, I recommend you cut off the bar and tack weld a handle on it to save the last few inches of that 1084 from sacrificial toasting. Rebar works great for that.

For everyone else paying attention to this. After discussion with Bruce and some testing of the blade I made, we determined that thinning the sides may not have the effect I want. Even towards the tip the blade is not stiff enough, and that was at .100" thick. I am thinking it may not have hardened properly where the cladding was(aldo's thicker 15n20 might not be deep hardening enough) so I will attempt to water or brine quench the blade and see what happens.

Darcy:)
 
Bruce Culberson said:
I'm not worried about a couple inches of bar stock....
Click to expand...

I guess I'm cheap:p

An update, I rehardened the blade, this time water quenched, and I can still bend it by hand......not easily, but if I put some oomph into it, it will take a set. Core would skate a file after the quench. Just not enough thickness in the core I think. Maybe I will finish grind it and see how it holds up to some abusive cutting tests.

Darcy
 
DEllis said:
I guess I'm cheap:p

An update, I rehardened the blade, this time water quenched, and I can still bend it by hand......not easily, but if I put some oomph into it, it will take a set.

Darcy
Click to expand...

I'm not saying this is necessarily the ideal for a knife, but frankly most thinner Japanese laminated blades will take a set if you put some oomph into it. Just the nature of the beast.
 
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I decided to finish grind, sharpen and whup on this blade a bit. It performed well. Chopped dry pine, tested the point strength by stabbing into dry pine and snapping the tip out sideways, cut some cardboard, and finally gave it the antler chop test. No damage. No bending chipping or rolling of the edge. I also threw it at a piece of OSB(hard) and basically tried to get it to bend with heavy use. No problems.








So I hand sanded and etched in FC. Then I decided(after scuffing the finish on the wrought iron) that it needed heavier oxides to protect the soft iron cladding, as well as add a bit more character. Enter the blue bleach etch. This was the result.

I think it is worth finishing.

I'll post more pics as I do the handle and fittings, but it may take a while as my real job gets in the way..........

Darcy:)








 
DEllis said:
I guess I'm cheap:p

An update, I rehardened the blade, this time water quenched, and I can still bend it by hand......not easily, but if I put some oomph into it, it will take a set. Core would skate a file after the quench. Just not enough thickness in the core I think. Maybe I will finish grind it and see how it holds up to some abusive cutting tests.

Darcy
Click to expand...

I agree with the other poster that what you have attained is the desired purpose for san-mai and suminagashi. It should have a core that is very hard, but thin enough to flex without breaking/cracking. It should have sides that are soft and tough, so that if the blade gets severely torqued, it will bend and not break. Straightening is simple and can be done in the field. If a blade was not desired to have this ability, it could just be made from mono-steel.

Additionally, in many cases, the steel under the cladding is pearlite, which will also bend and not break. If a fully hard core is desired, use a deep hardening steel with a larger pearlite window for the core.

The decorative aspect of san-mai and suminagashi is a secondary benefit.
 
Thanks, Stacy, for the information. I generally prefer a blade that is able to do some prying without taking a set, but this was an interesting learning experience anyway:)
Darcy
 
Stacy E. Apelt - Bladesmith said:
I agree with the other poster that what you have attained is the desired purpose for san-mai and suminagashi. It should have a core that is very hard, but thin enough to flex without breaking/cracking. It should have sides that are soft and tough, so that if the blade gets severely torqued, it will bend and not break. Straightening is simple and can be done in the field. If a blade was not desired to have this ability, it could just be made from mono-steel.

Additionally, in many cases, the steel under the cladding is pearlite, which will also bend and not break. If a fully hard core is desired, use a deep hardening steel with a larger pearlite window for the core.

The decorative aspect of san-mai and suminagashi is a secondary benefit.
Click to expand...

Stacy, what would you consider a good core for a wrought iron san mai?
 
Did this last year for a Bowie guard, never thought to use the same combo for a blade. Very nice.

3cd82328254aba65840bec3149308cf7.jpg



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