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A drawknife, also spelled draw knife, is a hand operated tool used to strip the bark off logs and shape wood, particularly in green woodworking. Green woodworking deals with wood that is still moist because it has yet to be dried, either naturally or with the help of a sawmill. The drawknife is primarily used for quick removal of excess wood and rough shaping. It is not typically suited for sculpting smooth curves in wood, though it is often used to make the approximate shape desired, after which another tool, such as a spokeshave or a lathe, might be used.
The blade of a drawknife is long and shallow with one beveled, or angled, side and one flat side. The handles are located at each end of the blade and are usually either perpendicular or continuous with the blade. The length of the drawknife varies based on its use; longer drawknives are typically used for tasks such as debarking logs and shorter knives are indicated for finer woodwork.
To use a drawknife, the operator grips both handles and draws the knife along the wood toward his or her body. The downward pressure on the handles determines the depth of the cut. For ease and safety reasons, the beveled edge of the blade is usually angled upward and the blade is rarely pushed away from the body. This can lead to a loss of control and potential harm to the user, as well as rapid dulling of the knife. Despite these hazards, some operators choose to use the drawknife with the beveled side down because it allows less wood to be removed. It is also possible to push the blade away from the body, though most people find this method awkward and prefer to turn the wood around.
Shaving wood with a drawknife is usually done from a seated position at a shaving horse. A shaving horse is a bench with a clamp attached. The user straddles the bench and steps his or her foot onto a bar below. The bar causes the clamp to close down on the woodwork, holding it in place so that the operator can pull the blade over the wood without it moving. The shaving horse also allows the operator to brace his or her feet so that more body weight can be put into the pulling the blade.
To make a level cut in the wood, the operator should begin in the center of the work and bear down evenly as she pulls the drawknife toward himself or herself. The work should then be unclamped and turned around so that the operator can repeat the process from the other side. When making a concave shape, or an inward curve, the operator should put more pressure in the center and less pressure as the blade comes to the body, so that the cut becomes less deep toward the outer edges of the work. Convex shapes, or outward curves, are made by the opposite process, with a shallower cut at the center and deeper shaving on the outer edges.
One of the most common uses for a drawknife is stripping bark. The log is locked in place with a vise or a shaving horse while the operator pulls the blade with consistent pressure and fast movements toward the body, repositioning the log in the vise as needed. Often, this is the first step in shaping beams or making rough cylinders that can then be finished in a lathe. A lathe is a machine with a rotating component that turns the work and a stationary component that sands or cuts it into a smooth, symmetrical shape as it spins. A hand tool called a spokeshave can be used to finish the same kinds of work as a lathe, such as chair legs or spokes for a wheel.