Hello, I am using 18K white pallidium wire and 18K white medium
solder. I am having two problems:
-
There is a noticable color variation. (slightly important)
-
When I polish near a solder joint, the solder seems to polish
faster leaving an unattractive dip and calling extra attention to an
area I would like to be invisible. (very important)
Help! Please! Can I fix this by burnishing or something? Next time,
is there specific white-pallidium solder that I should be using?
Thanks for your help,
Anastasia
Hello, I am using 18K white pallidium wire and 18K white
medium solder.
Hi Anastasia; Stuller makes an “extra easy” platinum solder that is
possibly mostly palladium. That would probably solve the color
problem, but it melts at only 100 degree F. below the typical 14K
palladium white alloys. You’d have to be nimble with the torch. 19K
white weld gold solder would possibly give you less problems with the
seam polishing out and it would be slightly cheaper, but the high
melting temperature and bad color match would make that a bad choice.
The best way to avoid polishing out seams, in my opinion, is to
design in such a way that your seams are generally on the inside
corners. When finishing, you can minimize the polishing out problem
by going through finer and finer grades of abraisive papers mounted
on rigid backings. Then use hard felt laps for the final finish, if
the design allows. Consider also, there may be cases when casting is
a better choice than fabrication simply to avoid the seams. Such
would be the case with a wedding band, as opposed to fabricating one
from stock and having to have a butt joint. I’ll be interested in
hearing input from those who have more extensive experience with
palladium.
David L. Huffman
Help! Please! Can I fix this by burnishing or something?
Next time, is there specific white-pallidium solder that I should
be using?
You can partially avoid the hardness problems by using harder
polishing compounds. In particular, the platinum polishing compounds
sold by Gesswein, which are micrograded aluminum oxide in a hard
binder, are ideal. The fact that these compounds are a hard
abrasive, rather than things like the usual oxides and silica based
compounds, means they don’t tend to discover hardness differences as
much between different metals, but cut everything fairly uniformly.
Use harder buffs too, to help avoid the pulling out of the softer
metals, and where possible, buff across such joints, rather than
parallel to them. You may find that some of the silicone rubber
wheels designed for final polishing may be better able to keep a
smooth surface without digging out the solder. So are the 3M bristle
disk brushes, which are available all the way up to a grade that will
leave a nice polish, perhaps needing just a very light and gentle
final buffing with rouge, not enough to dig out solder, but to give
that final high gloss. The 3M bristle disks seem almost tailor made
to avoid this problem, in cases where they can successfully reach and
polish the surfaces you’re having trouble with. But you need to go
through pretty much the whole sequence of grades, as they’re not, in
the very fine grades, agressive enough to remove scratches much
deeper than the previous grade would leave.
To avoid the color differences, use as tight and well fitted a joint
as possible (also helps with polishing out the softer solders), and
if needed, rhodium plate the finishe work. You have little choice
here, since the solders are generally a lighter color than the
sometimes brownish tinted palladium white golds. And finally, (and
this applies to all white gold work), always use the hardest/highest
melting solder you can manage with white golds. White gold solders
are notorious for being softer than the golds being soldered, and
solder drag-out is a regular problem for joints being done with the
easier grades (and medium us a somewhat easy grade for white golds,
especially with palladium whites, since they melt significantly
higher than the nickle white golds) Sizing seams, for example, are
often done with virtually welding grades of solder, just to avoid
this problem.
Hope that helps.
Peter
Anastasia,
You will be able to solve the problem by using an 18K palladium
solder. It is available from Hoover and Strong of Richmond, VA.
You can slightly alleviate the dip problem by sanding the area with
the finest sandpaper you have, 4/0 if possible and then polishing as
lightly as possible. Tripoli and fast cutting compounds will
aggravate the problem so use them as little as you can. Polish and
sand diagonally to the seam, not parallel or directly against it.
Still, the color difference will mean that even if there is no "dip"
you will still be able to see the seam.
Palladium solder from Hoover only comes in hard. You will need to
plan for this when you make your work. Perhaps others know of
where, and if, it can be purchased from other companies.
Larry
You might try using 19K WW (White welding) solder. Stuller and
others have it. I’ve used it for soldering 14K palladium white
bezels with good results. It’s also good for ring sizing, producing
an invisible seam. Very high melting point, however. You have to
be careful. -BK in AK