A disadvantage of the dado joint is that its joint line is visible. Click to see larger view Figure 3-38. The arc area of the stopped dado can be cleared out with a chisel; the shelves can then be fitted this way. Rabbet Cuts-A rabbet is an L-shaped cut made on the end of stock or along the edge. The width of the cut may be gauged with the miter gauge stop rod or by using a spacer on the rip fence. Warning: Never position the miter gauge stop rod so it crosses in front of the dado accessory. When rabbet cuts are needed along the length of stock (this may be called for when the back of a bookcase or other project is recessed into the frame), the rabbet is cut with the stock sliding against the rip fence.
Be sure that the stock has ample bearing surface against the insert. To ensure that the groove will be exactly centered, assemble the dado accessory parts to make the cut narrower than you need. Make one pass and then turn the stock end-for-end and make a second pass. A tongue is formed by making matching rabbet cuts on opposite edges of the stock. Always cut the grooves first and then form the tongues to fit. The tongue is formed by making two opposing rabbet cuts on the stock’s edge. Make a first cut with one side of the stock against the fence and make a second cut after turning the stock end-for-end. It’s easier to make adjustments for the rabbet cuts that form the tongue, so always shape the grooves first and fit the tongue to the groove.