I took some photos tonight while I sharpened my adze. I wrote about my general sharpening procedure for an axe in this post a while back. The general idea is the same, but sharpening an adze can be more intimidating due to the curves and geometry of the cutting edge. I wrote a bit about that stuff here. But really, its pretty straightforward. There are lots of good sharpening techniques. Here’s the way I go about it.
First check for excessive rounding of the outer bevel. Carefully rock a straightedge down onto the bevel (see below). It is absolutely acceptable if the bevel is very slightly and gradually convex. It is a tool for hollowing after all, and with this slight roundness, the edge will still bite instantly and glide through the cut. However, roundness much beyond this — especially any abrupt rounding at all near the cutting edge — is a problem. If that is the case, the bevel needs to be reshaped/flattened. Rather than go into that right now, let’s assume all is well in general with the bevel, and the tool just needs to be honed.
I hold the adze in my left hand with the edge pointing up. This allows me to manipulate the adze and see when the stone, held in my right hand, is flat on the bevel. I rock the stone onto the bevel, and I’m ready to hone.
I move the stone in small circles, maintaining contact with the bevel throughout. the movement from corner to corner.
The scratch pattern provides feedback on how well contact across the bevel has been maintained. It may be helpful to blacken the bevel with a Sharpie to see the contrast more clearly.
Once I feel a slight burr along the entire inner bevel, I continue working the outer bevel with a finer stone. Once I am finished with the extra fine stone, which may be all that was needed in the case of a little touch-up, I move on to the inner bevel.
I use a very fine ceramic teardrop slip at this point, rocking it down onto the bevel, then sliding along the inner bevel until the burr is on the outside.
I can feel the burr on the outside. Then i use the flat portion of the same slip to lightly hone the outer bevel, which pushes the burr to the inside… This procedure continues until the burr is gone. Sometimes the wire edge can be seen as it falls away.
Stropping polishes the edge and removes any fine burr that might remain. I use a slip strop on the inner bevel.
I protect the edge with a good guard or sheath. This is my favorite, a gift from a friend, and fellow carver, in Indiana who had it custom made.