Fitting Window Sash. Sash are often fitted before the house is plastered and before the sash are glazed. (1) Joint the top and sides of the top sash, chamfering the arrises very slightly by a stroke or two with the plane. (2) Cut and fit the meeting rails about the parting stops remembering to leave a little "play," that successive coats of paint on the stops may not cause binding, 1/16 " on each side is not too much. (3) Joint the edges of the lower sash. (4) Since the bottom rail has not been beveled, only the lugs sawed off, the meeting rails will appear with reference to one another as in Fig. 129. Set a pair of dividers to a distance equal to that between the tops of the meeting rails. This can be done by-placing the dividers between the meeting rails. (5) Scribe the bottom rail as indicated in Fig. 130. If the sash has been glazed so that the outer face of the bottom.rail is not accessible from the inside, the scribing is to be done on the inside of the bottom rail and a T-bevel set to the slope of the sill and this used to transfer the angle to the edges of the sash. Before scribing the bottom rail, see that the meeting rails are apart a uniform distance across the sash. (6) Saw and then plane to the scribed line.
Where sash weights are to be used, they are easiest placed before lathing. The proper tying of a sash cord so that it shall not work loose with time is a matter for careful instruction by the teacher. No good carpenter will have his sash cords coming untied. The cord can be cut the estimated length after the weight has been attached, and a knot or loop tied in the free end so that the cord shall not slip thru the pulley.
In case weights are not placed before the lath and plaster, it will be necessary to make use of a "duck" to draw the end of the sash cord up thru the removed pocket cover of the jamb. This " duck " is usually a piece of lead beaten about one end of a piece of stout short cord. This lead weight is lowered thru the pulley by means of a longer cord, the end of the sash cord is then fastened to the longer cord, after removing the duck, and then drawn up and thru the pulley.
To determine the length of sash cord, draw the sash weight to the top of the jamb and, setting a sash upon the sill, mark and cut the cord about four or five inches below the opening in the edge of the sash in which the knotted end of the cord is to rest.