Shaping by Hand

I have never sharpened a blade before heat treating. I have always done a regrind after heat treating. I don't know what the affects would be if sharpening before heat treat.


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If a man can keep alert and imaginative, an error is a possibility, a chance at something new; to him, wandering and wondering are a part of the same process. He is most mistaken, most in error, whenever he quits exploring.

William Least Heat Moon
 
I have a great tool that I use for removing a large amount of metal by hand. It's like a file but looks like ten high quality hack saw blades bent into zig zags and riveted together to leave diamond shaped spaces between them.

My dad got me one years ago in the US so I know that you can get them there. These are made in Japan and the one I have now says "Shinto" on the handle. One side is like a hack saw and the other side is much rougher.

I just finished a lock back folder using one of these and it really does the job. I made the blade from a 5 mm (about 0.20 in)thick stainless damascus blank I purchased.

If you're interested but can't find a source let me know and I'll see what I can do.

 
Nomad, I have no idea where to start searching for the tool you describe.
It sounds very useful.
Maybe after another cup of coffee I'll come up with some leads.
If you can give me some more info, I'd appreciate it.
The Shinto reference makes me wonder if the tool started out in Japan and only returned via your dad's puchase.

About the sharpening prior to heat treatment, I have no special desire to do so; it just seems like it would take extra energy and concentration to shape the blade almost, but not quite to the edge.
I don't want to mess with a system that has worked well for someone else.
How "unsharp" do you leave the edge?
If I remember correctly, Bob Engnath shipped his blades after heat treatment with a visibly flat edge.



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Luke 22:36, John 18:6-11, Freedom

 
The problem with sharpening before heat treat is that the blades will warp and break.If the edge is to thin then it will shrink and expand more and faster with temperature change than the thicker part of the knife.Which means all of the filing would be for nothing
frown.gif


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Fix it right the first time, use Baling Wire !
 
Matt, speaking to the warping problem, someone sent me a link to an illustrated Bob Engnath "how-to" which addressed differential hardening with clay and how the selective application of heat and different rates of cooling could/would make a blade curve.
Whoever shared that link with me, thank you.
I mention this not to suggest that anyone could/should use clay to get around warping, but as an acknowledgement that it makes more sense now to leave a thicker edge until after heat treatment.
Thanks for making the connection for me.
What kind of pre-heat treatment edge to most makers leave on the blade?

I assume that one still has to contend with warpage during heat treatment regardless of the edge configuration.
Would heat treating the bar stock and annealing it prior to shaping reduce the tendency to warp?
What about cryo pre-treatment?


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Luke 22:36, John 18:6-11, Freedom

 
By the by, as for edge geometry and blade section; I think hand filing a blade leads very naturaly to a convex edge with a slight convexity to the entire blade. Getting precise hard edges breaks between bevel planes is very difficult with hand files. The tendency is to rock the file and round it off. Go with the flow, the natural motion of the work, and you end up with a superbly functional and more "organic" profile.
 
Phillip, did you do the inside curves in the waist of your blade with a flat file or with a rounded file?
I would very much like to follow the shape of your example, and I wonder if the waist might present special problems.

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Luke 22:36, John 18:6-11, Freedom

 
I used a 1/2inch round file to cut the curves into that section of the blade.


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If a man can keep alert and imaginative, an error is a possibility, a chance at something new; to him, wandering and wondering are a part of the same process. He is most mistaken, most in error, whenever he quits exploring.

William Least Heat Moon
 
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