[TheForge] soldering v brazing v welding (fyi)

[Hochewa at aol.com]

To All,
Soldering and brazing blur as the temperature increases.  One way of  looking 
at it is to evaluate the amount of alloying that takes place between the  
lower melting point material (solder or braze) and the base metal.  In  soldering 
there is usually only a wetting of the base metal with the  solder.  In 
brazing there is substantial alloying between the braze and the  base metals.  For 
those of us who work in Silver, the alloying effect  becomes quite apparent.  
If you are not too generous with the braze, i.e.,  silver solder, upon 
subsequent heating of a joint, the solder used will  melt less and less due to the 
fact that you are diluting the solder with the  base and raising its melting 
point.
Now if you solder lead pipe, is it brazing or soldering?
 
Hochewa
 
 
In a message dated 3/17/2006 12:34:52 P.M. Eastern Standard Time,  
sunironworks at yahoo.com writes:

Soldering - The AWS defines soldering as a group of joining  processes
that produce coalescence of materials by heating them to the  soldering
temperature and by using a filler metal (solder) having a  liquidus not
exceeding 840ºF (450ºC), and below the solidus of the base  metals.

Brazing - Brazing joins materials by heating them in the  presence of a
filler metal having a liquidus above 840ºF (450ºC) but  below the
solidus of the base metal.

Welding - In welding, fusion  takes place with melting of both the base
metal and usually a filler  metal.