Soldering Aluminium to Copper or Brass.
—Aluminium can be readily soldered to copper or brass with fine solder (2 parts of tin and 1 part of lead): tin the metals, using stearin as flux previous to making the required joint. It is essential that both the “tinning” and soldering should be thoroughly done. Do not expect the solder to pull the joint together, but see that the joint is kept under slight pressure until the solder is hard, otherwise the joint will not be perfect. Many workmen refuse to place any reliance in such joints.
Finally, it seems very likely that, at any rate as regards factory work, the use of solder on aluminium objects will be wholly discarded in the future in favour of fusion welding or autogenous soldering, in which process no alloy is interposed between the surfaces to be joined. Information on the subject is given towards the end of this book.
CHAPTER VII
Wiping Joints on Lead Pipes
Plumbers make joints in lead pipes with soft solder which, by means of cloths, they “wipe” to the shape shown by [Fig. 47].
[Figs. 46] and [47] show the difference between a copper-bit or blowpipe joint and a wiped joint.
Fig. 46.—Copper-bit Joint on Lead Pipe
Fig. 47.—Wiped Joint on Lead Pipe
