CONSTRUCTION 



105 



material for top and bottom frames. If working in brass, the upper and 

 lower frames should each be left in one piece. By accurately bevelino 

 the two ends and preparing right-angle cuts at three points, as shown in 



Fig. 86. Cut, Preparatory to Bending Angle Brass 



above figure, the whole can be bent into a frame that will produce very 

 neat corners and make soldering easy. The right-angle cuts should be 

 finished with a square file and carried within about 1-32-inch of going 

 through. This leaves the bar very weak at these points and considerable 

 care is necessary in handling in order that some accident does not break 

 them apart before it is time to bend. If one breaks it is not a very 

 serious matter, only the corner will not have quite such a neat appearance. 

 In practice we find it best to bend each cut as soon as finished and roughly 

 fasten with solder. When all three bends have been completed, place 

 within it a wooden form, as shown below. Except for the corners being 



Fig. 87. Frame Secured on Wooden Form 

 Note Reinforcement in Upper Right Corner 



cut off (to allow for soldering), the edges of form should be perfectly 

 rectangular and fit closely. Now secure quite firmly with stout twine. 

 After all corners are trued up with the board, apply the permanent solder. 

 Melt solder from any corner that does not stand true without forcing, and 

 re-solder. In the upper-right corner of illustration will be noted a right- 

 angle flange reinforcement, cut from a flat piece of 1-16 inch brass. It is 

 advisable to use these. They add greatly to the strength and actually 



