58 Laboratory Arts 



in fitting, and all the joint should be visible through the slight 

 "skin" of solder used to fix the materials finally. In addition, 

 it may be noted that a well-fitting joint takes the solder without 

 trouble, while an ill-fitting joint is exceedingly difficult even to 

 make watertight. 



IV. ADDITIONAL METAL-WORK PROCESSES. 



Riveting. Rivets are used for joining metals where 

 soldering or brazing is impracticable, or where these joints 

 would not be sufficiently strong. 



Rivets are usually made of copper or malleable iron ; wire 

 nails (French nails) make excellent rivets for many purposes, 

 though copper is to be preferred. Contrary to general opinion, 

 riveting is a simple process, and one easily accomplished, the 

 only trouble being in the drilling. 



Rivets may be made from copper wire (No. 16), or from 

 wire nails, or they may be purchased generally from saddlers 

 or ironmongers. Washers usually accompany them, but these 

 are not absolutely necessary, unless the material to be riveted 

 is soft, when a washer is, of course, indispensable. 



In making a lap joint of metal, rivets should, if possible, 

 be put in in two rows, " staggered," as shown in Fig. 54, this 



giving greater security from 

 cracking than if they were 

 all in a line. In riveting 

 strips of metal together, 

 washers are not necessary, 

 but sometimes make a more 

 satisfactory job, as they take 

 all the strain of hammering. 

 The necessary holes 

 having been drilled, a rivet 

 is slipped into place, and 

 held upon an anvil, while the 

 tail of the rivet is hammered into shape. This tail should not 

 project more than i J to 2 diameters above the hole, and the 

 rivet should fit the hole tightly, or it will bulge, and tend to 

 separate the plates. 



FIG. 54. Positions of rivets in riveted 

 lap joint. 



