A coping saw is that thin-bladed, hunchbacked manual handsaw great for intricate scroll cuts and coped molding cuts.
For the most part, the 6 1/2-inch long, 1/8-inch wide blade is stretched tightly between the two ends of a 4 1/2-inch to 5-inch U-shaped frame held in place by spigots that allow the user to loosen and move the blade to different angles.
Most often used with the blade positioned to cut on the pull stroke, it can be turned around to cut on the push stroke.
Television personality and skilled woodworker Norm Abram said that a coping saw is one of the few types of saws that he keeps in his tool chest for everyday challenges.
In addition to inside molding corner joints, coping saws are nice for inside, tight radii holes. To use the saw this way, bore a hole in what will be waste following the cut, insert the blade into the hole and re-attach it to the saw’s frame and cutaway.
The blades range from 10 to 20 teeth per inch.
According to the authors of Basic Carpentry at Sunset Books, it helps to clamp the piece of wood that you’re working on to a workbench or in a vise to hold it fixed while you make a coping cut.
The average homeowner might find when buying a coping saw that the tendency is to go cheap because making coped joints isn’t something he or she plans to do too often, but that could be a frustrating mistake.
If the frame is too flimsy, the blade can’t be kept rigid enough to make an accurate, clean cut.
An ingenious technique called coping can get a good fit at molding joints in inside corners.
A finished coped joint appears to be a perfect miter, in which the ends of two mating pieces of molding are cut at 45 degrees. In coping, however, only one of the pieces needs to be cut.
Here’s how to cope a joint:
— Put the molding in a miter box and make a 45-degree cut, in the end, to be joined, using a backsaw or fine-toothed hand saw. This cut exposes the molding profile on its front side and leaves a wedge of wood extending beyond the profile.
— Remove the molding from the miter box and outline the profile with a pencil for better visibility while completing the cut. Next, position the molding on a workbench or other surface so the cut end can be trimmed.
— Use a coping saw — a special handsaw with a very narrow blade and U-shaped spine — to cut along the molding profile and remove the wedge-shaped piece of wood left by the miter saw that extends beyond the profile. It is best to angle the coping saw slightly to remove a little more wood from the backside of the molding than the front, but the front profile must be followed exactly.
The coped cut should form a duplicate of the shape of the molding face that the coped piece will join. The coped piece and its mate can then be butted together neatly at the inside corner.
Test fit the pieces, and trim the coped joint if necessary with sandpaper or a sharp knife.
A properly coped joint will fit well even if the walls don’t meet exactly 90 degrees (few walls do).
Some other tips for installing molding:
— When marking molding for saw cuts, make a small X or other marks on the waste side of the cutting line. This ensures that the cut won’t be made on the wrong side of the line and produce a molding that is short of the intended length.
— When possible, paint or finish molding before nailing it in place. The result of prefinishing will be better appearance and less mess.
— Molding is installed with finishing nails, slender nails with small heads. Even though the nails are thin, molding is often so fragile and easily split that it is best to drill a pilot hole through the molding before inserting a nail.
— Drive nails until the heads almost reach the wood, then use a nail set to countersink the heads slightly below the surface. Fill the holes over the nail heads with wood putty.