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Hello Scott:

You might want to try not using solder at all. I am assuming you
are sizing a ring. Take a thin piece of Pt stock (.25mm) and
wedge it into the cut seam of the ring. Let it be about 1/2mm
bigger all the way around. With a very hot oxydizing flame , fuse
the thin piece into the shank all the way around. That will make
a complete metallurgical bond as it becomes part of the ring. Now
file, sand and finish as usual and there will not be a seam to be
polished out and the color is a match as you are using the same
material the ring is made of. You see , only the very high
temperature solder such as "1700seamless "or "Pt weld "contain
platinum. All other solder does not. It is softer than the
Platinum and therefore will either polish out or discolor in
time. The welding procedure outlined above will fix that. Hope
that has been of help. For more help call our hotline at 714
760-8882 Sincerely PLATINUM GUILD INTERNATIONAL Jurgen J. Maerz
Manager of Technical Information

Scott Hepner wrote:

I spend alot of time working with platinum. As such, I was glad
to get your message.My question is:Do you know of any platinum
solder that does not drag out of solder seams and matches the
color of platinum well?

Scott - I’d recommend fusing your parts, especially in sizing.
This can best be achieved by rolling out a very thin strip of
platinum to wedge in between your two pieces. Once this is done,
heat the platinum evenly on the joint until your stip curls into
the metal. Then clean up as normal. As always, remove all
stones from the mounting (or utilize a heat sink) before
soldering platinum with a platinum material. When this is not
possible, I’d recommend 19K White Weld solder. The fusing will
definitely cure your solder line problems - if you stick with
plat solder (hard for sizing), try sanding to a fine finish -
vertically to the joint, then buffing with platinum tripoli
(again against your joint), then moving to yellow and green
rouge. This works pretty well too. Polish on, Mike

I usually work with silver (occasionally gold) and have been asked by
a friend to fix a platinum ring which cracked at what appears to be a
spot where it was previously sized using solder.

How is this repair done? How different is platinum from silver and
yellow gold? I have both a torch using just acetylene and a smaller
torch using both oxygen and acetylene. Which is better for this job?

thanks in advance - Lori

Lori, if you’re a bench jeweler, you would be well advised to invest
in a single station water welder. You can generate intense localized
heat far in excess of what is required to melt platinum. The reason I
say well advised is because I have learned through experience. You can
still do it with oxy-acetylene but it’s more of a pain in the —.

If you suspect there is garbage solder, the first thing to check is
to see if the ring was sized down and not up. If it is sized up,
you’re better off taking the insert off all together. Whatever is
there, file it all away including back from the joint to ensure you
only have platinum left.

Order an 1100c platinum solder which is a good solder for general
repairs. Don’t prep the joint in any way (no fluxes, etc.). Just put
the solder where you want it and hold it down with a pick. When it
balls up, it will begin to adhere to the shank surface so it won’t
want to fly away. Apply the heat again until it flows. As soon as it
flows, it will migrate throughout the joint which is why platinum
soldering (welding) is so easy.

If you want a stronger joint, then go up to a 1300c solder. Water
welders can be gotten used pretty cheaply either through Gold
Machinery in Pawtucket, RI (Cliff Davis) or A&A Machinery in
Providence, RI (Tony Santoro). Because I’m lazy, I don’t use solder
sheets and hold the piece down with a pick. I use solder paste and
squeeze the amount I want onto the joint. These pastes or the sheets
of solder, can be gotten through any supplier. grab a dwt of at least
three different heats.

Hope it helps


I do not claim to be some “expert”, but I do know what I have learned
over the past 30 years, and I feel some clarification is needed here.

First, a soldered joint is NOT a welded joint. For platinum sizing,
a welded joint is preferable to a soldered joint. Learn the

1100 plat. solder is the lowest melting point (1832 degrees F) plat.
solder available. Also called “Extra Easy” solder. A low melting
temp. solder used to repair near other soldered areas. Not suitable
for a proper sizing joint. Easily buffs out of the joints and has a
noticeable color difference.

1300 plat. solder (2372 degrees F), “Hard” solder, is a good solder
to use for assembly work where no other plat. solder is present. I
have used this solder for sizing when necessary, but this solder also
polishes out of the sizing joints.

1700 plat. solder(3092 degrees F), “Seamless” solder, is the
preferred solder for sizing. Melting temp. is close to the melting
temp. of platinum (1774C, 3225F), so temperature control is necessary
or you will be welding instead of soldering. If that’s too close,
1600 (2912F) solder works.

Plat sizing is much like white gold sizing. The highest karat
(fineness) solder must be used or the sizing seam will show after
polishing. Actually, welding the sizing joint is the preferred
method of sizing platinum, but a high fineness solder is acceptable
if done properly. Using the higher grade plat. solders take a bit of
practice and protective glasses must be used. Protective glasses are
highly recommended when soldering, especially welding, platinum
throughout the temperature ranges.

As to which torch is needed for platinum working, I have used a Hoke
torch, LP gas (Barbecue grill) and oxygen, for 30 years with great
success. The Hoke is capable of generating enough heat to melt
platinum while still allowing control of the process, which is
necessary when either soldering or welding, especially in the
presence of other grades of solder.

Flux and Boric Acid dipping is not advised when soldering or melting
platinum. Has to do with the high heat involved and the gasses of
the chemicals being absorbed into the metal leaving pits.

Using platinum solder around stones is not advised. Diamonds can be
damaged by the heat necessary to melt the platinum solder. If
in-place diamond tipping is necessary, use plat. stock with 18K W
solder. And be careful with the temperature.

If you are not familiar with working platinum, it can get to be an
expensive learning experience. Practice with a piece of scrap first,
and above all, use the welding glasses. The temperatures generated
produce a bright white light capable of damaging (permanently) the

<< If you suspect there is garbage solder, the first thing to check
is to see if the ring was sized down and not up. If it is sized up,
you’re better off taking the insert off all together. Whatever is
there, file it all away including back from the joint to ensure you
only have platinum left. >>

Excellent advice.