Metal Working Tools 37 



The work being metal, and thus of high conductivity, speed 

 in soldering is of first importance. 



The bit of the soldering iron should first be filed clean, at 

 the point or along the working edge. Then it should be 

 heated, in a gas flame, if possible, but the flame should never 

 play directly upon the working part. When the bit is fairly 

 hot sufficiently hot to cause an appreciable glow immediately 

 when placed i" from the face, but short of red hot (at which 

 temperature copper oxidizes readily) it should be dipped for 

 an instant to a depth of f" into a saturated solution of zinc 

 chloride, and immediately pressed upon a piece of tin plate 

 (an old tin lid answers admirably) upon which lies a piece of 

 solder. Solder and soldering iron are pressed together, in the 

 presence of zinc chloride, when the solder melts, and flows 

 (" runs ") along the portion of the copper that has come under 

 the influence of the zinc chloride, leaving the iron ready for 

 use. This " tinning " of the iron should be freshly carried out 

 whenever the bit becomes corroded, or ceases to permit the 

 solder to flow readily. 



Pliers. So many patterns of pliers are now on the market 

 that it is difficult to recommend any one in preference to 



FIG. 25." London" pattern, taper-nose cutting pliers. 



another. Each pattern has its own advantage, and performs 

 one particular duty with more pronounced success than others. 

 So long as the cutting jaws actually close, the design of the 

 other portions of the tool is unimportant Many forms of 

 cutting pliers, however, only cut thick wire, the cutting edges, 

 when the jaws are closed, being still some distance apart. 

 Pliers with cutting edges and rounded noses are, on the 

 whole, more serviceable than the heavier square-nosed tools, 

 as they are more easily used in a corner. These are 

 known as " London pattern " pliers and are the most generally 



