Does anyone have any laser welding tips for repair on monel, base
metal, and titanium eyeglasses? Even with monel blue flux and argon
gas, I continue to have brittle fusion and breakage.
Gary L. Mills
Hi Gary
What kind of machine are you using? What settings are you using for
your weld? How did you deteremine the material construction of the
frames.
Thanks
Paul DeFruscio
Hi Gary
I too have a laser welder, and have been offering eyeglass repair as
part of my shop service. I know where you are coming from with your
statement. There seems to be many different types of alloys used to
make eyeglass frames, and there are a couple that just won’t bond no
matter what technique you use. I find with the base metal frames, I
have very good luck using just sterling silver wire. On a few
occations I have used 18K yellow wire and it bonded well. With some
of the titanium alloy frames, I have the most problem with brittle
weld. Like you said, even under argon, the weld is still very
brittle. When you get good, high purity titanium frames, they weld
beautifully. My rule of thumb is, when I watch the puddle during the
weld, if it cools to a flat grey color, I don’t waste my time
repairing the frame…it will break later. The puddle needs to shiny
and smooth, and then the welds seem to have much more integrity.
Overall though I find eyeglass repair to be a real crap shoot. What
I ended up doing was offer my customers a 15 day money back
guarantee. If the frames broke, I would not repair them again, just
refund the money. I would estimate that I get about a 10 % refund
rate, and lots that I simply return to the customer after the first
shot with the laser. There is not a million dollars in the service,
but it has produced several new and valuable customers to my main
business operation…making jewellery.
Hope that helps a bit. If you have any more questions, don’t
hesitate to contact me off list.
Regards
Dave Mereski
Gary,
I just returned from an advanced laser workshop at Rofin and part of
it dealt with eyeglass repair. It seems a lot of us have trouble with
them. One of the important points was to use argon, which you are
doing. But they also pointed out that too much argon will also create
a bad joint that’s brittle and breaks. They suggested a setting of
around 8-10 millibars on the argon and slowing down the speed of the
exhaust fan, so the argon stays in the chamber longer and the tank
therefore lasts longer. Weld a small amount, using eyeglass repair
wire, on each side of the break. Then align the pieces and weld
together. In essence, you’re welding the repair wire on each side to
itself. It wasn’t the first time I had heard this technique but the
idea that too much argon could be harmful to weld joints was an eye
opener. Now I’m far from an expert on eyeglass repair, but maybe
their advice could help you.
James S. Cantrell CMBJ
Gary
I laser weld tons of eyeglasses. I set my laser at a setting that
fuses the break in a smooth weld not a weld that blasts the metal I
beat the metal to the center of the break with an aggressive setting.
I then fill it with silver wire that I get from the company I bought
my laser welder from Zahntec. It is an alloy that they make and and
not silver solder that many laser welder companies sell. I do little
clean up on the frames. On titanium I use argon my welder haas a
nozzle and placement of the nozzle is important. If the titanium
blues or has oxide coloration on it the argon is not bathing the
weld. and the weld will be brittle a good weld will be shiney and
clean of oxide coloration. I flex the frame slightly to test the
weld. The only frames I have had problems with are the flex frames. I
have not been able to get them to weld.
Good luck.
J Morley
I have a Zahntech LWD 4V laser welder. On base metal and monel the
best luck I am having is using low reflective index sterling silver
30 guage wire. My setting are 1.8 kilowatts (power), 0.8mm spot (beam
diameter), 2 milliseconds (time), & 5 hz (frequency). The titanium
setting I have almost no luck with my setting at 2.2 kilowatts power,
0.8mm spot or beam diameter, 1.3 millisecond time, & 5 hz fequency.
Gary L. Mills
Gary:
If you don’t have argon, forget about welding titanium. Get some
silver solder wire from Stuller or form the developer David Brown in
San Diego that is made for welding titanium. Grind the break back a
little on each side and at an angle and “tin” the ends with the
silver solder. Regring the ends forming an open v between them and
weld filling v with more solder.
I learned this technique 3 or 4 years ago from David and have had
very few welds fail.
If the weld turns blue, you are screwed.
JB