In-furnace soldering is a technique used quite a bit by dental
techs to join bridge work after the porcelain has been applied
and glazed and it will not tolerate a direct flame. The pieces
are joined with stickey wax or Duralay (dental acrylic),
invested in soldering investment, and slowly brought up to
900-1000 degrees F. which burns the wax or plastic off
cleanly(let it heat soak for about 10 min.) Solder which is
fluxed is placed in position (the areas to be joined should have
flux applied before they are covered with the wax or Duralay).
The object is then slowly brought up to soldering temp. If the
solder is reluctant to flow, a gentle tap with a solder pick
on the investment will usually do the trick. Large flat pieces
can be set on a piece of fire brick with the fluxed solder
already stuck in position.
Duralay is a marvelous product. It is a powder(polymer)/
liquid(monomer) plastic that is dimensionally stable. It can be
carved with burrs at slow speed and can also be used to make a
single sided mold to reproduce single sided pieces. Any
mistakes in the carving can be fixed with wax. If anyone wants
more info they can E-mail me directly.
NRA Endowment and