Sharpening

Woodworking tools are useless unless they are sharp. Learning to sharpen is an ongoing process; I have tried a number of methods and find that my technique and the materials I choose to use continually evolve.

There is not a right or wrong way to sharpen tools. If the tool gets “sharp enough to shave with” then all is well.

Sharpening basically involves bringing two edges to such a fine point that they almost disappear into each other. The two surfaces are ground with increasingly finer abrasives until what had been a scratched piece of metal becomes a mirrored surface.

What follows is a very basic overview of my sharpening process. You can find much more detail on the web, in books or by asking me a question. Please feel free to ask questions!

The first order of business with chisels and plane blades is to flatten and polish the back. The back of the blade forms half of the edge. If the back of the blade is not flat and polished the edge will never be precise; it will show small imperfections and nicks and the edge will not stay sharp very long.

Flattening the back of the blade is a tedious process but well worth the effort. The back of the blade is held flat against the stone and polished until it is smooth. This is repeated using increasingly finer grits.

Here’s the set up I use most often for sharpening. I use several diamond sharpening stones. They cut quickly and always stay flat. The flatness provides a constant reference and keeps edges and the backs of blades straight and true.

I have a very coarse diamond stone that works so well I rarely use a grinder anymore. I have a few finer grit diamond stones that bring the edge to a usable sharpness very quickly.

I use a fine Japanese waterstone for the final sharpening and polishing. The waterstone brings the edge to a mirror finish. I use the diamond stones to keep the waterstone flat.

On the bench you can see the sharpening guides I use. These are very helpful with maintaining a constant angle when bringing an edge to shape. I use them all the time with plane blades and chisels though I often work freehand when touching up a blade that is beginning to dull a bit.

Last but not least is a hand grinder with a hard felt wheel charged with a fine honing compound. This makes quick work of sharpening a knife, putting a razor sharp edge on a chisel and sharpening various odds and ends around the shop. It isn’t absolutely necessary to use the grinder for these tasks but it is a lot of fun!

In the future I’ll write about different types of bevels and angles for special tasks, blah blah blah….