Jacob Reverb
06-06-2008, 8:36 AM
Hey, all,
I just bought a drawknife on ebay. It's fairly sharp but nowhere near where I want it, so I began the chore of sharpening it.
It originally had a straight 10" edge, but from years of use and sharpening it now has a bit of a "belly" in it.
I rigged up a jig to hold it at 30° so I could begin bringing the high spots on the ends down and thus begin to straighten the edge. However, when I tried to file the high spots down, the file wouldn't "bite" at each end of the edge -- only in the middle where the steel was softer.
My theory is that someone along the line somewhere took a grinder to the edge, got it too hot in the middle, and drew the temper out of it.
My question is, once I get the drawknife back in shape with a flat back, a straight edge and a 30° bevel on one side of the edge, can I then heat treat it to harden the softer steel back up, and if so, how?
What Rc hardness should a drawknife typically be?
And what temperature/time would I need to heat treat it to get that hardness?
Thanks in advance for any advice.
Jacob.
I just bought a drawknife on ebay. It's fairly sharp but nowhere near where I want it, so I began the chore of sharpening it.
It originally had a straight 10" edge, but from years of use and sharpening it now has a bit of a "belly" in it.
I rigged up a jig to hold it at 30° so I could begin bringing the high spots on the ends down and thus begin to straighten the edge. However, when I tried to file the high spots down, the file wouldn't "bite" at each end of the edge -- only in the middle where the steel was softer.
My theory is that someone along the line somewhere took a grinder to the edge, got it too hot in the middle, and drew the temper out of it.
My question is, once I get the drawknife back in shape with a flat back, a straight edge and a 30° bevel on one side of the edge, can I then heat treat it to harden the softer steel back up, and if so, how?
What Rc hardness should a drawknife typically be?
And what temperature/time would I need to heat treat it to get that hardness?
Thanks in advance for any advice.
Jacob.