|The top knife was polished on the back while the bottom was a rusty pitted mess|
|The bevel wasn't much better|
So after honing, I would strop the edge, which gives a subtle rounding and allows the drawknife to follow the fibers and come out of the cut on command. Just the right amount of rounding has always been tough to accurately reproduce. The problem is that once the edge is rounded, resharpening means either reflattening the bevel and back on the stones to reach the edge and then stropping it again to re-establish the correct shape or simply stropping the edge until the rounding becomes too much for a good cutting angle, at which point it's back to the grinder. Does this sound at all familiar?
|The back is still largely a rusty mess, but after 10 minutes of work, the edge is sharp|
I suppose my understanding started to change when a student, Steve Kinnane, came up with the idea of grinding the drawknife using the back (spine) of the tool as a reference. I adopted this wholeheartedly for it's ingenious simplicity. You can grind a curved or straight knife with control and ease after smoothing the spine of the tool, which is almost always soft enough to be done quickly (and only once) with a file and some abrasive.
Then one day, I thought, why not use that same unchanging reference to hone the edge? And the wheels started turning, leading to the Drawsharp. I suppose my reluctance to spend time tuning my collection of drawknives should have highlighted the problem sooner. Flattening the back of a drawknife is really just labor, not skill. Yes, honing a ground edge freehand is a valuable skill for some tools, but doesn't offer an advantage to drawknife geometry or sharpness.
I use the drawknife from the time that I split a piece from the log to the last cuts on a finished chair, so it must be as sharp as any tool that I own. Using the spine as the correct reference has made sharpening knife easier and I can honestly say that I no longer have a "favorite" drawknife. I used to coddle certain knives, never letting them touch green wood. No, these were my finish knives and unlike the other lugs, they were kept in top shape, mainly because of their seldom and restricted use. Now that I know the exact geometry of my edges and have a way to quickly and repeatedly tune them, I can get all of my blades singing. The only difference between my knives is the quality of the steel and the comfort of the handles. As far as top performance and geometry for cutting wood, the mystery is gone.
I appreciate that you've stuck with me through this and hope that you understand my intention in enlisting the help of Benchcrafted to make the Drawsharp available. I want folks to work with sharp tools instead of fussing about and eventually giving up thinking that a razor sharp drawknife is limited to those experts who possess skills that they cannot muster. After much practice, I can freehand grind a drawknife and hone it beautifully on my waterstones, but honestly, it's no longer a skill that I value. Sharpening a drawknife to work at it's peak is no more complex than using the correct references, the real skill building belongs to using the tool to make great furniture, and having fun doing it.
Soon, I will be posting a video of fully rehabilitating a drawknife in hopes of getting more folks using the most versatile tool in my shop.