[Illustration: The belt pin]
Eighteen-gauge copper is required for this problem. The operations are
like those for the hat pin except that hard soldering is necessary. The
slight bending of the copper, required in this case, is done by means
of a horn mallet and a sand pad. For hard soldering, the surface must
be scraped as before and covered with a little borax ground in water
and applied with a small brush. The belt plate should then be placed
on the asbestos pad, with its convex face down, and blocked up so that
the end where the soldering is to be done is horizontal. The catch
should then be placed in position with a small piece of silver solder
at the base. The solder should be melted as before by means of a mouth
blowpipe and gas or alcohol flame. The hinge is soldered on in the same
way, and finally the pin is cleaned and polished for use.