A small repair such as eyeglass frames should be a job that many RCMers
could perform fairly easily.

The manufacturing process is most likely a machine that passes electrical
current through the contact area of two pieces of thin frame material.
The current generates very localized heat, and the hard silver solder/braze
material joins the two pieces. The joint cools quickly after the current is
switched off, so the brazing is done almost instantaneously.

A way to improvise an electrical resistance heating machine may be possible
with some equipment that many metalworking enthusiasts may already own.

A bandsaw welder could very likely be adapted to pinch the pieces together
and apply enough heat to the junction for brazing. It would probably require
fabricating a couple of copper contact tips to be held in the clamps for the
blade.
Many blade welders have a low-power setting for annealing the blade after
welding has been accomplished. The annealing heat level would be more than
adequate to reach the heat level required to braze the eyeglass frame parts
together.

A resistance-type spot welder may be another option for the small eyeglass
frame parts brazing.
If the spot welder has a selector switch to bypass the automatic cycle
timing circuit (manual over-ride), or if the operator can figure out how to
accomplish the bypass, the S-W machine should be capable of heating the
joint into the heat range of brazing with hard silver solder.

Since the OP's parts were previously brazed, the process may work very well
by just reflowing the existing braze material with a little flux, although
adding a small sliver of silver solder and flux may be required after a
thorough cleaning of the joint (and perhaps strengthen the joint if it was
weak).

Some MIG welders (and others) have the capability of heating steel to red
heat with a carbon rod held in the gun assembly/torch (for autobody
heating/shrinking). An older Solar/Century model that I bought several years
ago covers this procedure in the users' manual, and came equipped with the
torch adapter and carbon rod. The rod is kept in contact with the metal (no
arc) and can be moved around in an area for wider heating.

--
WB
..........


wrote in message
...
I broke a joint on a metal eyeglass frame. The local eyeglass place
that last put new lenses into the frames (they did not originally sell
me the frames) apparently does not have a repair service to direct me
to and suggested that I go to a jewelery repair. I braise and silver
solder - if I bought a "jewelers torch", would that give me a small
enough of a flame to be able to silver solder the frame? Years ago I
tried to repair a broken joint in a scrap pair of glasses and tried to
either use a TIG or oxi-acetylene (I don't remember which) but all
that I accomplished was to burn away about 1/8 inch of the frame near
the joint. That failure was no loss on the trial frames but my
current frames are in daily use and I expect to keep them in use for
another 1/2 year and then have them as back up eyeglasses after that.