Cabinet-makers use glue instead of nails for fastening parts together. Glue is made from the strippings of hide, from horns, hoofs, etc., of animals. These are boiled to a jelly-like consistency and chemically treated to give a clear color, and remove the disagreeable odor. As glue liquifies very slowly, it must be heated in a double boiler, Fig. 107, the outer pot containing water.
Glue is prepared by soaking it in water over night, then applying a steady heat to the outer pot or kettle. Water is added as the glue cooks until the glue has a consistency which will flow freely when applied with a brush.
Fig. 107. Glue Pot.
Fig. 108. Hand Clamp.
Fig. 109. Bar Clamp.
Fig. 110. Position for Adjusting Clamp.
Clamps are used to expel the surplus glue from between the parts being glued together. Two kinds are in common use, the hand-clamp, Fig. 108, and the bar-clamp, Fig. 109.
In placing the hand-clamp, see that the jaws are kept parallel, adjusting by rotating the clamp as in Fig. 110. Tighten the back spindle last.