Edge grinding, wet Media
Published: 10 years ago
A few folks have asked me to show my edge grinding technique. I don't claim this is the fastest way to grind the edge, but in about 10 minutes per knife I form a very clean consistent polished edge that is both durable and extremely sharp.
Specifically, I'm using coolant, light pressure and low speeds to avoid loss of hardness at the very apex of the edge. And I'm achieving an accurate repeatable edge angle by using a hanging parallelogram to maintain a specific angle. And (not shown) I'm dealing with the wire edge by applying a micro bevel on a fine stone.
I sharpen at about 500 SFM, edge leading, on 120 grit, then 40 micron then 15 micron. I then turn the platen from 18 degrees to 20 degrees to do a small micro bevel with the belt reversed so it is edge trailing, at about 100 SFM on a fine film belt. This prevents the rounding of the edge where the belt bunches up, but creates a wire edge. I then remove the wire edge by hand with a few passes on an oil stone. After a light strop it is a fiendishly sharp high quality edge that is full hardness and without any burr.
This is not the fastest way to sharpen a blade, but in my experience it is the best way to achieve a high quality edge in a somewhat repetitive semi-production environment.
None of this is special or unusual except perhaps the hanging parallelogram which I have not seen used like this before. Hopefully someone will find this helpful.
Specifically, I'm using coolant, light pressure and low speeds to avoid loss of hardness at the very apex of the edge. And I'm achieving an accurate repeatable edge angle by using a hanging parallelogram to maintain a specific angle. And (not shown) I'm dealing with the wire edge by applying a micro bevel on a fine stone.
I sharpen at about 500 SFM, edge leading, on 120 grit, then 40 micron then 15 micron. I then turn the platen from 18 degrees to 20 degrees to do a small micro bevel with the belt reversed so it is edge trailing, at about 100 SFM on a fine film belt. This prevents the rounding of the edge where the belt bunches up, but creates a wire edge. I then remove the wire edge by hand with a few passes on an oil stone. After a light strop it is a fiendishly sharp high quality edge that is full hardness and without any burr.
This is not the fastest way to sharpen a blade, but in my experience it is the best way to achieve a high quality edge in a somewhat repetitive semi-production environment.
None of this is special or unusual except perhaps the hanging parallelogram which I have not seen used like this before. Hopefully someone will find this helpful.