I have a couple of titanium wedding bands that I want to solder
sterling silver bezel cups to.. Can it be done? What kind of solder?
You cannot directly solder to titanium in the usual methods. The
oxides on the titanium surface are too tenacious for soldering fluxes
to penetrate, so solders don’t work.
Instead, solder a fairly heavy wire to the back of the bezel cup (or
two of them is even better). Drill matching through holes in the
titanium bands, and cut a bevel on the edges of the holes on the
inside of the bands. Insert the wires, and rivet the bezel cups to
the band. Obviously, on the inside of the band, you can’t close the
rivet with just a hammer, but you can make a chasing tool, rather
like the shape of the bend “inside ring” karat stamps, and use that
with a hammer to flare the ends of the rivet. If, instead of wires,
you used tubes, then you might be able to expand the tube rivet ends
with just a burnisher you could reach into the band with. In any
case, the idea is cold joints, rather than soldered ones.
If you really want a soldered or welded joint, it IS possible, but
not with a torch. A laser welder, using argon sheilding, can do it.
So can a PUK welder, or the “Sparkie” type fusion welder. For the
last, you’d have to make your bezel cups (or buy them if you can find
a source) with the needed little dimple on the bottom that lets the
fusion welder work, and you’d need an appropriate chuck for the bezel
cups to hold on the welder (and you need the sparkie welder). if
you’ve already got bezel cups, you can produce that little dimple by
drilling into a steel block with a number 80 drill, then hold the
bezel cup over that hole, and punch down hard in the center with a
chasing tool, which drives a little of the silver on the bottom into
the hole, giving you that dimple. The only reason I mention this is
that the fusion welders are the cheapest of all these technologies,
and they weld to titanium very well. And once you work out the
tooling (chuck, making the dimples, etc), the fusion welders are the
fastest as well.