Sharpening knives and scissors

A friend who has been sharpening tools for a very long time; to near obsession (which is a very good quality), offered to give me a lesson and some pointers on the art of sharpening knives and scissor blades.  Thanks Paul.  Incidentally, he’s the same guy who won our club’s Best in Show with this beautiful ume!

His recommended shopping list:

•  220 grit water stone
•  800 grit water stone
• 1200 grit water stone

(I bought King brand stones on Amazon for around $28 each)

• Nagura stone (this is a very soft stone used to build up a slurry on the sharpening stones.  More later)
• Simichrome; a lightly abrasive chrome polish
• Rubber-bottomed clamp to hold the stones still
• Cafeteria tray to contain the water
• Rubbermaid bin to soak the stones
• Cardboard from a cereal box for stropping
• Rags

Soak the stones in water for an hour or so prior to use, and be sure the tools are clean before starting.  First, use the nagura stone in a circular motion on the sharpening stone to develop a slurry.  The nagura stone is the limestone-looking smaller stone on top of the green 220 grit stone in the photo below.  Notice the slurry building up in the sharpening stone?  That’s the good stuff. I bought one that so far, hasn’t been as satisfactory.  I think it’s a manufactured 12000, and natural is the way to go.  Spend more on the nagura.

Lay the blade so it is flat on the stone, with the cutting edge on the stone, blade parallel to your shoulders, and push straight and flat across the length of the stone. Nice even pressure, smooth, and repeating strokes.

Notice the “tidal wave” of slurry Paul is generating with this push stroke?  Sprinkle water on the stone every few strokes, and turn the stone 180 degrees to keep the wear even, and the slurry on the stone.

The shiny edge must be in full contact with the sharpening stone, dead-flat and straight through the length of the stone.  

You’ll know it’s dead-flat when the face of the blade is even.  The photo below is the same as the one above, but the still-shiny spots are highlighted (I probably could have chosen a better color).  Once the whole face is consistently even and flat, we can move on to the finer, 800 grit stone.

Repeat the process with the 800-grit stone, remember to use the nagura stone to create the slurry, sprinkle water onto the stone, and keep the strokes as consistent as possible.  After a while on this stone, he flipped the knife over, laid it flat, and ran it on the stone, leading-edge last to knock off the burrs on the blade.  With scissors, it’s important to never touch the inside edge to the stone.  The inside edge needs to stay flat for good contact, only work on the beveled, outside edge.

Then, repeat the process a third time with the 1200-grit stone.  No pix, but you get the idea.

Next, stropping is done in the opposite direction as sharpening; pulling the blade toward you. He puts a small amount of Simichrome on the cardboard, and pulls the blade toward him with the cutting edge trailing.  Start with the rough side of the cardboard, and then flip over to the smooth side.  Paul uses pieces of cereal boxes, clipped to a clip board:

Shiny side next:

Here is the sharpened, finished product.  I was running short on time, and got the sense that Paul would have been happy to spend another hour or two on this.  In the interest of time, he graciously moved on to the scissors.

Scissors are handled the same as the grafting knife, but just remember to only sharpen the beveled side of each blade.  The interior, flat sides cannot be ground down or it will result in a gap where the two blades don’t contact while bypassing, and it won’t really matter how sharp the blades are if they have nothing to shear against.  Also, clean the blades well before starting so you don’t foul the stones.

This is a big undertaking, and I can see setting up everything in the dead of winter and cycling through all the tools, taking my time and carefully getting everything ready for spring.