Rabbet joints utilize a rectangular cut on the edge of a board that looks like a small shelf. The cut creates a tongue that is either overlapped on a flat edge or two rabbet joints are fit together. The rabbet joint is also known as a rebate.
Two styles of rabbet joints exist. They are the double rabbet or overlap rabbet. The double rabbet and shiplap joint has a rabbet cut on both mating ends or edges of the work piece. The rabbet cuts are identical for a tight fit. The shiplap joint creates a flat surface where the double rabbet will create a 90 degree angle. These types of joints will always form a perfect right angle. The overlap rabbet joint has a very deep rabbet cut on one board so it will fit over the entire square end or edge of another board.
A common use for double rabbets and overlap rabbets is in bookcase construction. This is due to the fact that the ends and edges of the sides, top and back panel can be hidden. The rabbet joints are excellent in covering the end grain of the wood.
Rabbet joints are normally glued in place. Small brads or nails are tacked into the narrow edges of the rabbet joint to help hold them into place.
Shiplap joints are preferred over edge-glued butt joints because there is more surface for gluing. The shape of the rabbet allows for a step type pattern to use to place the glue. This allows for one third more surface to place glue. A properly cut rabbet joint will resist shifting in the wood while the glue sets.
Cut a rabbet joint using a standard kerf saw blade. Cut the cheeks with one blade setting and the shoulder with a second. When cutting a double and shiplap rabbet joint it is important to mark the rabbet layouts against one another. Make sure the proportions drawn will fit snugly together once they have been cut. It does not matter whether the cheek or the shoulder is cut first. Novice woodworkers should cut practice rabbet joints prior to working on their desired woodworking project.
Make cheek cuts by standing the piece on edge against the rip fence. It is advisable to use a tall fence and a tenoning jig to support the wood while cutting the cheeks. Make sure to cut the cheek on the inside of the rabbet joint markings to prevent cutting into the tongue of the joint. Set the blade to the level of the rabbet joint to avoid going into the main body of the board.
Cut the shoulder for the rabbet joint using the rip fence as the guide. Use a miter gauges as a guide to set the blade height for cutting the shoulder. Remember the shoulder is cut into the check and does not cut all the way through the wood. On overlap rabbet joints it is important to reset the saw blade as the shoulders are shorter than the cheeks.
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