236 SHEET-METALWORK 



before the soldering operation begins, by means of a stick or 

 brush. This flux may be used on almost any metal except 

 aluminum, zinc or galvanized iron. 



FIG. 261. Equipment for soldering. 



The Soldering Process. Certain metals require special 

 solders and fluxes. For most purposes, however, the solder 

 and fluxes described are serviceable. 



The best of tools and materials, however, will not secure 

 good results unless used in the hands of a good workman. 

 To solder successfully the metals to be joined must be fitted 

 accurately and cleaned thoroly, either by some means of 

 mechanical cleaning, such as scraping or grinding, or by re- 

 moval of dirt and grease with acid. 



It is dangerous to use the latter, however, as it may injure 

 the metal surfaces, besides its possible injurious effects upon 

 the workman. 



