[Platinum] Solder becomes very brittle

I’m having a problem that I’m hoping some of the platinum
workers out there can help me out with. I’m attempting to make a
bunch of jump rings for making a loop-in-loop chain necklace.
I’m using 20ga, 950 platinum alloy (Hoover & Strong Plat/S+)
wire. So far I’ve tried using 1400 and 1500 solders to close the
loops. The solder becomes very brittle, and the loops snap open
when I start to bend them. Could someone please give me some
basic platinum soldering tips. I’m using and oxygen/propane
torch, if that helps.

Thanks in advance,
Alan

P.S. If I could only make it down to New York this weekend…

Alan Derr
Westford, MA USA
@Alan_Derr

Make sure you are soldering on a non-carbon surface. Ceramic of
some sort, able to take that heat. The bottom of a wesco fused
silica melting crucible is very good.

Also, don’t use flux to hold the solder. Some fluxes can
contaminate platinum, causing exactly what you describe.

And be sure that your flame is a sharp oxidizing one. A soft
flame will allow carbon contamination to take place.

If you need to use a solder poker or tweezers, don’t use steel.
tweezers are commonly tungston carbide tipped, or of plain
tungstem metal. You can get tungston wire/rod at any welding
shop, where it’s sold in about 6 inch lengths as tig welding
electrode wire. This wire is safe to use as a soldering poker
for platinum if you need, or can be made into tweezer tips.
Carbide is a bit better, but is more of a heat sink too.

Also, I wonder why you’re using the plat SK alloy? This is an
alloy specifically made for heat treating for increased hardness.
Almost by definition, it will be more difficult to work into a
proper chain, as it is likely to be a bit less forgiving of
temperature variations. When you solder, for example. Are you
sure you’re not slightly hardening a bit of the link? It’s a nice
alloy for things where you NEED the hardness and strength. I’d
sorta not think a loop in loop chain to be the best place for
that alloy. Among other things, it’s lower melting point means
you MUST use these lower melting solders. Remember that these
platinum solders don’t even contain platinum, but are mostly
silver and palladium alloys. Already sometimes not the
strongest joint. you’d be better off with 10% iridium platinum.
THOSE links you’d not even need to solder. You could easily just
fuse them…

Hope this helps.

Peter Rowe

Hi Alan,

If you are using flux or boric acid either will make your seam
brittle. Just put your solder in the seam and solder. Also using
1700 will be invisible, better yet weld with a very thin piece of
the wire you are working with.

Mark P.

Hi Alan, My guess is that you are using boric acid/alcohol on
the platinum and possibly flux as well. All of these are
verbotin in the soldering of platinum as they infiltrate the
grains of the metal causing brittleness. Good luck, Mike.

I would fuse the jump ring together, if this does not work I
would use 1700 solder. I use a mini torch for jump rings. Also
be sure to use dark enough eye protection.

Good luck
Bill Wismar
http://web.wt.net/~bill (temporary url untill domain remapped

its taking to long to reach temp also it seems you are using a
oxidizing flame, this will cause the platinum that flowed to be
foam like instead of solid…I rairly use solder when I’m
connecting pieces most of the time I allow for fusing which
creates no solder joint.Again this must be done with a hot tight
flame.Hope this helps … The Ringman

Hi Alan,

Although I’m a chain maker, I’ve never tried to make a platinum
chain: but it’s close to the top of the ‘to do’ list.

Just a thought, have you tried fusing the links? If they can be
fused the resulting link would be the same metal all the way
around. Any link forming operations would affect all sections of
the link equally.

Let us know how you make out.

Dave

 The solder becomes very brittle, and the loops snap open
when I start to bend them. Could someone please give me some
basic platinum soldering tips.

Alan,

Your problem is probably from some sort of contaminate. Be sure
your work and work area are clean. Use platinum specific holding
tweezers,soldering block, solder pick etc. Don NOT use flux or
boric acid as these will embrittle the joint. My guess is that
one of these is the problem.

Good luck
Wayne Lenkeit

Alan, There is no need to use any solder on the joints. Welding
the rings used for a loop in loop chain is the best option. The
joints need only be aligned properly and welded with an oxidizing
flame. If your torch control needs some work, placing a small
pallion of the same platinum you are welding together between the
joint may be easier. The pallion should be hammered very thin
and extend only slightly beyond the edges of the joint. Note:
that using different alloys of platinum when welding will cause
pitting and brittleness. Also platinum will not oxidize when
heated (except cobalt alloys),so be sure to not use any flux when
welding, it will cause contamination of the joint.

	Good luck,  Mark

Hi Alan, Since you are having troubles with two different DWT’s
of solder, I doubt its the solder. Are you using flux to hold
the solder snippet to the jump ring, If so this may be your
problem. The borates in flux will cause brittleness. If you are
using a solder pick other than tungsten this could be the
culprit. Both steel and titanium are contaminates, only tungsten
or ceramic tweezers are safe for platinum. When I first started
to work with platinum I made the mistake of soldering on top of a
charcoal block and got similar results. Carbon contaminates
platinum at high soldering temperatures. If you are going to
place work on a soldering block, make sure it is a Wesco style
board.

I hope this helps,

Blaine

   If you are using flux or boric acid either will make your
seam brittle. Just put your solder in the seam and solder. Also
using 1700 will be invisible, better yet weld with a very thin
piece of the wire you are working with. 

Do keep in mind, folks, that Alan says he’s working with the
alloy Steve Kretchmer developed and released through Hoover, plat
SK. That alloy melts significantly lower than iridium/platinum.
You can’t use solders higher than 1500 with it, I believe.

   I would fuse the jump ring together, if this does not work
I would use 1700 solder.  I use a mini torch for jump rings. 
Also be sure to use dark enough eye protection. 

Normally, I’d agree with you. But he’s using the new SK
platinum alloy from Hoover and Strong. This is a Steven
Kretchmer heat treatable alloy, dirived from the alloys he
developed for his tension set rings. It can be heat treated to
almost a springlike hardness (not as hard as his own, original
alloys for the tension rings, but enough to give quite
respectable hardening) A key point to this alloy is that it
melts several hundred degrees cooler than iridium platinum, from
the PGI press release I first saw it mentioned in. That release
suggested that you cannot use a solder higher than about 1500
with the SK platinums. Further, I’m not sure how well this alloy
will fuse…

Hope this helps.

Peter Rowe

I have found the surplus tile for heat sheild on the shuttles
work excellent for high temp work. try boeing surplus on the
web…Ringman

Many thanks to everyone who has helped me with the “brittle
solder on Plat/SK” question. I think that the bottom line is
that I need to use a 900 plat/irid alloy for this work and fuse
the links. A couple of interesting points:

- I wasn't using flux (and was actually wondering if that was a

problem). It’s good to know that at least I was doing THAT
right!

- I determined that Plat/SK CAN be fused, but with great

difficulty. I was able to fuse enough links to make a couple of
inches of the chain. I found that, due to the alloy’s hardness,
the chain may have resulted in a very attractive, slightly
flexible ROD, but as a necklace, I don’t think it would have
worked.

- never buy two ounces of a platinum alloy you've never worked

with before, unless you really know what you’re doing. (It will
make quite a few very nice earrings, though.)

Thanks again for all the help. This really is an incredible
place!

-Alan

Alan Derr
Senior Applications Consultant
Summa Four, Enhanced Services Migration Business Unit (ESMBU)

Cisco Systems, Inc.
25 Sundial Avenue
Manchester, NH 03103 USA

Direct: 603-665-3138
Fax: 603-695-1243
Pager: 888-712-5430
@Alan_Derr