Soldering eyeglasses

How do you hold and solder broken eyeglasses? I don’t have a laser. I
use a propane/oxygen little torch with easy silver solder and handy
flux dark paste (for steel). The break is usually on the lens loop
right next to the bar that holds the two lens loops together. When I
get my solder hot enough to flow, I immediately unsolder the part
next to it (the bar connected to the circle). I don’t like to work
on them but I am the only guy in town who does in-store jewelry
repair work. All the optometrists in our county send their desperate
customers to me.

Thanks in advance.
Dale Pavatte

How do you hold and solder broken eyeglasses? I don't have a
laser. I use a propane/oxygen little torch with easy silver solder
and handy flux dark paste (for steel). 

I assume the frame is made of a nickel alloy and so the solder they
used is probably of lower temp than your easy. I would suspect they
used Easiflo as the optical parts supplier near me sells it as
optical solder. Operating temp 610C-635C (approx). Possibly all you
can do is get some easyflo siliver brazing rod from a plumbers
supplier, hamme/roll out an end of the rod and cut snips, put
heat-shield on the other joints and do the repair quickly.

I’d also add, steel black flux operates at too high a temp. Use a
flux that suits the temperature of the solder (rather than the
apparent metal being soldered). While at the plumbers get some
easiflo flux. In fact I use easiflo powder flux (as powder) on all my
gold and silver soldering jobs and find it to be just wonderful. Work
with a small fan blowing across the workbench.

... The break is usually on the lens loop right next to the bar
that holds the two lens loops together. When I get my solder hot
enough to flow, I immediately unsolder the part next to it (the bar
connected to the circle). I don't like to work on them but I am the
only guy in town who does in-store jewelry repair work. All the
optometrists in our county send their desperate customers to me. 

An unenviable job, but if you can crack it you’ll get more of such
jobs!

As for holding the frame as you work on it, first you need to
support the whole frame. I’ve learned to rig up a piece of st/steel
mesh (4 per in) in such a way as it follows the curve of the frame,
lean it on such an angle in the soldering bay that you can access the
joint well, and stick the frame on the mesh with lumps of soft clay.
two or three chunks, to hold the frame onto the mesh. The clay also
acts as a heat shield, so don’t put it close to the joint you’re
working on.

Cheers
Brian

Auckland
New Zealand
www.adam.co.nz

The one guy I know here that does these repairs commercially uses a
laser, and swears by it.

I’ve repaired my own and my partner’s frames a number of times.
Unless they are precious metal (unlikely these days), I use Tix
solder and flux; or on steel frames, black flux and either extra-easy
silver solder or Silvalloy brazing wire from the welding store. The
Silvalloy works particularly well, and the 40% version flows low
enough to avoid unsoldering other joints (usually). It also helps to
clamp a big heat sink right on the nearest sound joint, and get in
and out fast with a very small, very hot flame. A small alligator
clip or pair of cross-locking tweezers makes a decent heat sink.

Or you could try the old trick of burying everything but the joint
you want to solder in fine wet sand.

Of course, more and more frames these days are titanium, and you
can’t solder those.

Regards,
Bob Edwards
Chromis Designs
San Francisco

good morning,

Spirig manufactures those SPIRFFLAME[tm] precision flame generators,
you might have heard on our jewellers model KARAT250.

http://www.karat250.com

Repairing eye glass frames is a trickly job. Need is for tiny, but
still powerfull flames. Spirflame[tm] could be that source for you.

An old trick to somehow limit heat travel to nearby parts, by the
materials heat conductivity, is to wet a small piece of cotton web
(ear claener) and fix that to the area to be limited in heat
increase. as long as water can evaporate that piece is clamped to the
boiling temp of water at around 100C.

Give it a try.
Ernest Spirig