Last weeks post started me thinking about sharpening tools, so here, for what its worth are some random musings on the subject.
Professional wood-workers love fettling tools by hand when they have time to do so, but when working on site and under pressure they invariably use a belt sander to grind and hone all edge tools, even a course sanding belt gives a razor sharp edge in seconds but use a very light touch or the steel will burn and blue…a mug of coffee is frequently called in to keep blades cool when water is not available 🙂
When sharpening you do not need a guide, feel for the tool bevel riding flat on the stone – there is a bit of a knack for this, though. Standing off to the side and looking sideways at the tool on the stone helps.
Have a strong light overhead that casts the shadow of the tool onto the stone, when the shadow under the edge you are sharpening disappears, the tool is sharp.
The macho shave of the back of your hand is great fun for demonstrating how sharp the edge is but when you can look down the blade and the cutting edge is invisible then that is the best test of all because light is reflected off even the teeniest imperfection of the edge and will show as a silver line, when light cannot be reflected by the cutting edge then it is properly sharp.
Ignore all the information out there on cutting angles (except for planes and spoke-shaves where the angles are essential as the blade is locked into a cutting angle by the plane), everyone holds their tools differently and you need to find the angle that suits your style the best. I use a very acute angle on my blades as I find it easy to drive them but the trade-off is the blades are delicate and need more frequent honing.
Every carver is different, every carver has their own way to sharpen tools and their own way to use them, the only important thing is that your tools are sharp, not how you sharpen them.
There are a thousand ways to sharpen tools, from pebbles on a beach to grinding paste on a sheet of toughened glass, they all work.
When I started carving I used a craft knife and learned how to sharpen on craft-knife blades (told you I was cheap!) because I knew what they felt like to use when they were sharp, could see what a sharp edge looked like and could compare my attempts at honing to the new blades fresh from the packet.