Saturday, January 13, 2007
Planes, for Wood
All three planes here are smoothing planes. (Uh huh.) The plane on the upper left is a Japanese plane, and you can buy it from The Japan Woodworker. (Credit where credit is due, the picture comes from their online catalogue. They also sell kitchen and garden tools, and many things Japanese.)
The plane on the upper right was made by now deceased Maine planemaker, Cecil Pierce. (Until the invention of the all metal plane, planes were all wooden. Duh, you say.) This is an especially beautiful wood body plane. The wood and metal beauty is an infill-smoother. (Infill: wood, usually here, rosewood, packed into iron. Often, instead of screws, the metal is fastened together with sawn and filed, compound angle dovetails.) These grew out of British gunmaking traditions, and are sometimes called gunmetal smoothers. What makes a plane a smoothing plane? A couple of things. Generally they are vaguely mid-sized, 10,12, 14 inches long as contrasted with small block planes or the 22-24 inch long jointer planes. (Another aside, planes can be block, badger, molding, rabbet, compass, chisel, panel raisers, scrapers, scrub planes, fillister, combination etc. etc. The field is large.) The opening for the mouth, where the blade protrudes is tiny, maybe 2-3mm. Why? When the blade sticks out just a small bit, only very small shavings of wood are planed away. Why is this nice? Have you ever whittled at a dry stick of some hardwood, i.e. something not pine? Notice how the wood has a sheen when cut by a sharp blade? A good smoother in skilled hands will produce that sheen over a large surface. We like the sheens, on wood...Smoothing planes tend to be heavy; weight suppress vibrations, chatter we call it. If the blade chatters the fibers of the wood tear out instead of curling up into shavings. We don't like chatters. And smoothers must have very flat soles; the bottom of the plane is the sole. Planes also usually have chipbreakers. The smaller metal parts above on top of the blades are the chipbreakers. Chipbreakers are deflectors; they turn the cutting wood up so it begins to curl into a shaving. A good smoother will make shavings thinner than tissue. However, like target shooting, it takes practice and experience. (The untrained do not become Gil Shehan by just picking up that Guarneri violin.) The modern antidote to tear-out is sandpaper; it is immune to the affliction. Though the surface becomes very smooth, there are subtle differences in appearance. And a planed surface takes finish differently from a sanded surface. Sanding is a process of making finer and finer scratches on the wood until the scratches disappear from view to the naked eye. Sanding in surely easier, especially on woods with difficult grains. Teak, padauk and locust can be fearsome. (An aside about what's called roey grain. Grain in wood is just bundles of fibers, easily visible in a wood like red oak. In woods with roey grain, the grain in adjacent lines of fibers run in opposite directions. There is no planing with the grain in rooey grained wood. The fibers are interlocked, one row of grain cuts, its immediate neighbor tears. Plane from the opposite direction and the torn areas will cut smoothly, while the smoothed grain will now tear out. Fun huh? Still want to use handplanes? Good on ya mate!
This is as good a place as any to halt. Planes, chisels, sharpening stones et. al. are a huge room entered by many doors. Other tours for another day.
Posted by Kerry at 7:14 AM