Craftsman 17539 Operation Manual - Page 15

BUTT JOINTS A butt joint is made by mating the end grain of one board with the edge grain of another. The bonding of glue on this type of surface is poor. However, by using biscuits you can create a strong joint that gives a mortise-andtenon effect. MAKING BUTT JOINTS See Figures 11 - 12. • Unplug the biscuit joiner. • Place the two pieces of wood to be joined on a level workbench. Align them against each other in the arrangement in which they will be assembled. • Using a square, determine the location of each biscuit spline joint and mark the center of each joint by drawing a line across the edges of the two boards. • Loosen the locking knob and set the fence angle at 90 °. • Set the fence height at the desired dimension on the scale by rotating the height adjustment knob. NOTE: The scale indicates the height of the fence from the center of the blade. • Tighten the locking knob securely. • Select the correct depth of cut setting to match the biscuit size you are planning to use. Make a test cut in a scrap piece of wood from the same workpiece if possible. • Clamp the workpiece securely so that it will not move during the cut. • Plug the biscuit joiner into a power supply and prepare to make your first cut. Grasp and hold the biscuit joiner securely with both hands. • Place the fence against the board and align the indicator marks on the fence with the centerline mark(s) on the board. • Depress the switch trigger to turn on the biscuit joiner, then push it forward to extend the blade into the wood. • When the base assembly bottoms out against the depth of cut adjustment knob setting, pull back to release pressure on the spring. The blade will retract from the biscuit slot. • Repeat this procedure for cutting the slot in the mating workpiece. • Once all biscuit slots have been cut, place a biscuit in each joint and dry-assemble the workpieces. Make sure each joint lines up and fits. • Finally, disassemble the workpieces and place a bead of glue in each slot. Also, spread a bead of glue over the entire surface of the joint. Reinsert the biscuits and assemble the workpieces as shown in figure 11. • Clamp the workpieces together until the glue sets up. BUTTJOINTS UIT(S) I BISCUIT SLOT(S) J MULTIPLE BISCUITSSTACKED CENTERLINE MARK(S) Fig. 11 OFFSET BUTT JOINTS See Figure 12. The rails of a table or workbench are often offset from the front of the table legs. When offsets are required, it is necessary to cut the slots in the rails first, then readjust the fence to cut the slots in the legs. Keeping this one exception in mind, the procedure for cutting offset butt joints is identical to the procedure for cutting butt joints. For example, if a 1/4 in. offset is desired, you would mark the centerlines for cutting a butt joint as mentioned in the procedures for cutting butt joints, and cut the slots in the ends of the rails. Next you would raise the fence 1/4 in. to the desired offset and cut the slots in the legs. OFFSETBUTTJOINTS BISCUIT SLOT BISCUIT CENTERLINE MARK(S) Fig. 12 15