Coping saws are used to make curvilinear cuts in wood, laminates or plastic. The hardened steel blade is quite narrow, with fine teeth pitched at 14 to the inch. It is mounted on a C-shaped metal frame, with a wooden handle. The saw’s handle is in line with the blade, like a Japanese saw, and the saw is designed to cut on the pull stroke, rather than the push.
The coping saw blade is removable by partially unscrewing the handle, and then can be passed through a drilled hole in the middle of a piece of wood. The frame is re-attached to the blade and then cutting is begun from the middle of the piece.
To fit a new blade for replacement, the handle is turned counter-clockwise while restraining the blade holder pin from turning. Remove the old blade, and put one end of the new blade in the slot that is in the blade holder. To insert the other end, press the frame against a flat surface (handle end pointed up) and attach the free end of the blade in the rear blade holder. Ensure the blade’s cross pin is located in the blade holder’s groove, and that both blade holders are aligned with one another.
Due to the thinness of the coping saw’s blade, the contour of the cut is relatively easy to change while sawing, so small radius cuts are achievable. To cut thin material, the blade’s teeth are set facing backwards and the worked piece is set flat on a bench. To cut thicker material, the work can be clamped in a vise; the blade should be fitted to the saw frame with teeth facing forward.
One of the most popular uses is to cut moldings with a coped joint as opposed to a miter joint. (see picture above) In woodworking, is the technique of contouring the end of a moulding or frame piece to fit the shape of the adjacent piece, as shown in the picture to the left. Coping joints are designed to allow for walls that are not at right angles to each other.
|Coping Saw and Blades|
|For precise cutting of intricate or irregular shapes with precise control.|
A mitered joint has a tighter fit, but unless the walls are at precisely a 90 degree angle, the miter will have a gap. Coping joints are better for remodeling and renovation of older homes, I have found.
The other rationale for using coped joints is the fact that wood tends to shrink with age in width, much more than in length, and so effect of shrinkage is minimized compared to an internal mitre joint.
In order to cope a molding joint, you first need to cut a 45 degree bevel in the molding end. This will allow you to easily see the profile of the molding’s shape. You want to cut along the intersection of the beveled surface and the outside shaped surface of the molding. Marking the intersection with a marking pen can help, so give that a try.
An alternate method of marking the cut line is to place the mating piece of molding on end on top of the piece to be cut, and trace the outline of the contour with a pencil.
The next step is to start your cut. If you’ve never done cope cuts before, it’s best to use a piece of scrap molding to practice on, since it takes awhile to get the feel. Clamp the molding securely with a wood clamp, onto a work bench or sawhorse. The molding should lay flat on the bench, face up, with the end to be coped hanging over the end by a few inches. Trim away the marked area, while angling the blade slightly such that more wood is cutaway from the back side.
Final step is to test-fit the coped edge of the molding against the piece to be mated to. Any needed adjustments to the shape can be made with a fine-toothed file file or rasp.