Smoothing plane

Also called: smoother, smooth plane

A smoothing plane puts the final finish on a wood surface that other, longer planes have already flattened. It is the smallest of the bench planes, the family of planes used in sequence to flatten and true timber, and also the one reached for most often.

Last in the sequence

One older classification places it among six bench planes: the jack plane, the fore plane, the trying plane, the long plane, the jointer, and the smoothing plane, set apart from the cylindric, compass and forkstaff planes. In a fuller working sequence a roughing plane comes first, then a jack plane, then a jointer plane, with the smoothing plane last of all; it follows the jack plane in dressing timber and leaves a more even surface than the jack alone. It is also the shortest plane in that sequence, typically about eight inches long, and sizes vary enough that several are commonly sold, which may reflect disagreement over which length is best. A panel plane is a further size, intermediate between a jack plane and a smoothing plane.

Setting it fine

For fine work the iron is set to take as fine a shaving as it can manage, the mouth, the gap in the sole through which the shaving passes, is closed as narrow as possible, and the back, or cap, iron is set close up to the cutting edge. The iron itself is ground with rounded corners so that it will not dig into the wood, unlike a jack-plane iron, which is rounded across its edge for fast stock removal. A finely set example is treated as essential for levelling a surface.

Smoothing a frame

Ellis (1908) described the method for a door or window frame directly: "To Smooth Up, set the smoothing plane iron as fine as it will possibly bite, go over muntings, rails, and stiles in the same order as in trying off, but plane in the direction of the grain, finishing the rails exactly at the shoulders." Muntins are the vertical bars that divide such a frame, rails its horizontal members, and stiles its vertical sides.

Other uses

Wherever end grain, the surface left where wood is cut across its fibres, is exposed, a block plane or a smoothing plane brings it to a clean finish. A compass plane matches the smoothing plane in size and shape, except that its sole curves convex along its length, for working curved edges. A small smoothing plane can also readily form a beading profile. As Hasluck (1897) put it, the tool is "employed to give the finishing strokes to a surface which has already been flattened."