Facetojace gluing requires heavy, equalized pressure, and may utilize any or all three types of clamps, depending upon the sizes of the members to be bonded. When wide boards are to be joined, small brads tapped into one member and snipped off short will prevent creeping. Top and bottom bearers or battens can be used with hand screws or С clamps at both ends, when bar clamps are not available. Dowels are very useful for reinforcing boards glued face to face. In selecting the sides to be glued it must be remembered that the sap side tends to cup because it contains more moisture than the heart side. Therefore, in facetoface gluing the sap sides are joined with the grain parallel-never at right angles. Since the force exerted by shrinkage is tremendous, it is unfair to expect glue to perform a miracle. In view of this, whenever possible, lumber should be cut roughly to size and planed several days before the actual gluing is to take place. Edgetoedge gluing will be more successful if heart and sap pieces are alternated, so that whatever shrinkage results will produce a slight waviness, rather than a deep bulge. Bar clamps are convenient for securing this type of glued Fig. 1.37. Improvised bar clamps. CABINETMAKING joint, with large hand screws or С clamps and bearers along the edges. Bar cla may be improvised, as shown in Figure 1.37 or, if a heavy bench or table to available, a frame of 2 x 4's can be screwed to the flat top and the work wee into place, as illustrated in Figure 1.38. In all cases, the boards being glued n be kept flat with suitable wedges, to prevent their arching under pressure. Be the glue is applied the edges should be checked carefully against the light insure that the ends meet closely. A slight bulge in the center will be recti by the clamps. End grain can be glued provided it is first sized with a weak glue solutioi prevent suction. By thus filling the pores the final, extrathick glue coat will be too much absorbed. An endgrain glued joint is weak at best, and where со tions permit, a scarf joint should be substituted. For hardwoods the slope of scarf should be approximately 15 times the thickness of the stock. Framing is the classic example of "cramping" operations, and is of pi importance in furniture construction. As in all gluing procedures, the first ste to assemble the parts "dry," to see that the fit is exact. At this time a thoro check for wind and surface flatness should be made, and a test for square] carried out by means of diagonals and the try square at each corner. After the glue and clamps have been applied, if the work leans or twist: any direction, the clamps must be shifted or screwed in that direction for necessary correction, or a long bar clamp may be applied as a diagonal. In cases the clamping action must parallel the true pressure line. Miter gluing is an art in itself and various jigs can be devised to secui wellglued joint.