PATTERN MAKING 



glue, else the latter may be chilled and fail to set. The time re- 

 quired for well-made joints to dry so that the hand-screws can be 

 removed is from four to six hours. 



Sometimes a difficulty will arise in the case of large surfaces 

 011 thin material. When the glue is applied it moistens and expands 

 the surface upon which it is placed, causing the edges to curl up 

 and pull away from the adjoining piece which has a tendency to 

 move in the opposite direction. In such cases //err/' moisten the 

 back of the thin pieces with water from the outside kettle, as is 

 sometimes directed, but work quickly, spreading the glue rapidly 

 and then place between two thick, stiff pieces of board, previously 

 dressed true, prepared and heated for the purpose. Use as many 

 hand-screws as can be conveniently placed 011 the work, and allow 

 it to remain in these clamps until all moisture from the glue is 

 absorbed by the two outside, heated boards. Twenty-four, or better 

 forty-eight, hours should be given to this process if possible. 



All such gluing of thin pieces should in every case be done 

 first and allowed to dry while the other parts of the pattern are 

 being constructed. Under no circumstances use water on any sur- 

 face of seasoned wood. The reseasoning or drying out of such 

 water will invariably distort, curl, and warp the pieces so treated 

 after being glued together. Even the water contained in the glue 

 is objectionable, while unavoidable, and can be most satisfactorily 

 removed only as directed above. 



In all cases where end wood is to be glued, or where the grain 

 of the wood runs diagonally to the plane of the joint so as to pre- 

 sent the open end wood pores for the glue, this end wood, or parti a 1 1 y 

 end wood joints, should be first "sized' 1 ' 1 with thin glue, (glue; about 

 half the thickness of that used for gluing,) and allowed to dry. 

 This will raise the grain and roughen the surface of the joint, 

 which, when dry. must be lightly and carefully scraped off with a 

 sharp chisel, when it will be found that the open pores of the wood 

 are filled with dried glue. The joint may now be glued, and the 

 glue will hold as in ordinary jointing. 



HAND SCREWS. 



The hand screws, illustrated in Fig. 81, enter so largely into 

 all gluing for pattern work, that some description of their con- 



