Fish glue is not waterproof and may reqt warming during cold weather. Casein Glue. Casein glue has become increasingly popular in the home wc shop, owing to its strength and quicksetting and slowcuring properties. It coi packaged in powdered form with full directions for mixing it with cold wa Since it sets within 4 hours, only enough should be mixed for the job on ha It should be applied like liquid (fish) glue, and the clamps should be put within 20 minutes. The result is a waterproof, heatresistant joint, stronger tl the wood itself. Casein glue will deteriorate when exposed to salt water or action of molds. Latest reports indicate, however, that glue can be made resist to mold in warm, wet, tropical climates, by adding 5 per cent of an orga mercury fungicidebactericide to the dry glue; before the wood joints are bom together, one side is treated with a diluted formaldehyde solution. Plastic Glue. Plastic glue also comes in powdered form to be mixed with с water, according to directions. Unlike casein glue, however, the mixture will ] longer-about 6 hours at 700 down to 45 minutes at ioo°; in hot weather life of the mix can be prolonged by setting it in cold water. It is heat resist up to about 1500 F. and waterproof to both fresh and salt water. Resintype plastic is an excellent, waterproof adhesive, which comes in I forms. The fullstrength liquid plastic is syrupy and light colored, and requi the addition of a hardening agent just before being used. This is made by add ¦P. hydrochloric acid, 3 volumes to 1 volume of distilled water, well stirred a glass or porcelain container. A thin layer is brushed on both surfaces to Joined, before pressure is applied. At room temperature from 4 to 12 hours i • required for full hardening. This time can be reduced to about a half hour if can be heated to 1500 F. 38 . Emulsified plastic consists of a thin, white suspension of plastic in water and is slower setting and subject to more shrinkage than the fullstrength liquid. Clamps. Good glued joints cannot be achieved unless subjected to sufficient pressure while the glue is setting. Woods of ordinary densities require from 100 to 200 lb of pressure per square inch or, roughly, i bar clamp per foot for edgeglued stock i in. thick. Closegrained hardwoods require greater pressure. The pressure, however, must not be great enough to distort the wood. Although weights, ropes, chains, or wedging in frames can be employed, the old standbys are the hand screws, С clamps, and bar clamps. The hand screw is the oldest form of clamp and, when thoroughly mastered, is quite versatile. To open its jaws evenly, the handle of the middle spindle (nearest the jaws) is grasped with the right hand and the handle of the end spindle in the left hand, jaws facing outward. Hands rotate in a clockwise manner as the jaws are swung down and toward the operator until the desired opening is obtained. When being applied to the work, the middle spindle adjusts to the work size, then the end spindle applies the pressure until the jaws are parallel.