I have found a need to solder five platinum heads together for a
customer’s ring and am having difficulty setting them up and using
platinum solders to join the five with the proper contour and
alignment. I am laser-less, sparkie-less and Tack II-less. I am also
apparently clueless! Can anyone out there help? Can I use the old
clay and soldering investment trick at the high temps required?
Thanks in advance.
Jim Malone
I have found a need to solder five platinum heads together for a customer's ring and am having difficulty setting them up and using platinum solders to join the five with the proper contour and alignment. I am laser-less, sparkie-less and Tack II-less. I am also apparently clueless! Can anyone out there help? Can I use the old clay and soldering investment trick at the high temps required? Thanks in advance.
Jim, What I usually did, pre-laser, is to carve a curved depression
in a platinum soldering block that would allow me to just set the
heads in line at the right curve. Other tricks that work are
soldering, with just a tiny bit of solder, a thin wire to a prong
tip, and it’s other end to another prong tip. repeat with seperate
wires (and seperate tips, till you’ve got connecting wires between
all heads. the wires can now be bent till they hold the heads in the
right positions, and since platinum conducts heat poorly, you can now
solder the bases of the heads together without the wires becoming
unsoldered, so the wire fixtures hold the position of the heads, and
are then just cut off. This method works on many more complex
assemblies, but is somewhat tedious. It’s very good, though, when you
really need to get an alignment perfect, such as getting side stones
at the exact same angle to a center head, when putting together the
top cluster of a three stone ring… I’ve never tried using
standard casting investment to fixture platinum. It won’t, itself,
take those temps as an investment, but again, platinum conducts heat
poorly, and in this case, if the investment is breaking down, so long
as it still supports the heads, it might still work. worth a test
try. I’d not reccomend standard soldering investments though, as
these are mostly plaster of paris, which has even lower temp
tolerances than casting investment. If you really need an
investment soldering fixture, there ARE some new platinum investments
which are very quick setting (couple hours, instead of 24). These
certainly would work, but they’re pricey. And a final note, again
pointing out that platinum is a poor heat conductor, you may be able
to solder, using a good hard grade of solder, pairs of heads
together, assembling these then into the final group, or just adding
one head at a time to a group, rather than needing to line them all
up and solder simultaneously. This needs a small tight flame and
good heat control, but with care, previous joints as little as a
millimeter away can be kept from remelting, especially with the new
plumb platinum solders.
HTH
Peter Rowe
Jim The clay investment trick should work just fine, keep the “weld
point” away from the investment (platinum loves silica oxide) and use
platinum investment if you have it but regular jewelry investment
should work. Polish all the parts first. Unfortunately you might need
something like hydrofluoric acid to remove the platinum investment if
you do happen to melt the investment.