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Heavy Platinum Welding


#1

I have to size a gent’s plain plat wedding band two sizes up, not
stretchable. The cross section is roughly 3 x 5mm. I’ve carved a wax
for the sizing piece and will have it cast in plat (sizing wire is
not available in this chunky dimension). I’m concerned about getting
full penetration in the weld without melting the edges of the ring.
If someone has experience welding this hefty size I’d like any
insights you may have. Geez, I hope my torch is up to the task.

Thanks


#2

Hello Neil;

I have to size a gent's plain plat wedding band two sizes up... I'm
concerned about getting full penetration in the weld without
melting the edges of the ring. 

I’d recommend you solder it using one of the new plumb platinum
solders. They are pricey, but they will solder a seam in platinum at
a much lower temperature and provide a seam that has good color match
and won’t polish out. Stuller and R. Findings carry them, so does
United, I believe, and probably others. Stuller will sell half
pennyweight pieces of it. It comes in 1300, 1400, and 1500 degree
Centigrade melting temperatures. The lowest grade leaves a seam that
is barely noticible as slightly grayer than the surrounding metal.
The higher grades are progressively harder to detect. I’d shoot for
the middle grade of 1400. Use a neutral flame, not oxidizing as used
to fuse platinum, and don’t use any flux or boric acid coat.

The older platinum solder will leave a seam unless you get at least
a 1700 degree welding solder or higher, and those higher grades of
the old solders are nearly as expensive anyway. Next choice would be
to weld the seam using a laser, and, of course, the old method of
fusing the seam shut by inserting a thin shim of the same platinum
that is wider than the cross section of the ring. If it’s a plain
band, this isn’t really so risky as it sounds, but it does take a
little more experience than using solders. I use the new plumb
platinum solders for all my platinum sizing and thing they’re the
best way to go.

David L. Huffman


#3
I have to size a gent's plain plat wedding band two sizes up, 

Just fill it up with welding “platinum scrap” and smash it with a
hammer on the mandril. You can keep adding till it is all filled up.

Start with a good half size less as it will go up when hammering it.

Allan Creates
www.superringfit.com


#4

As I understand, you have plain platinum band with cross-section
5mmx3mm.

If you want to increase the size by adding a piece, one way to do it
would be to open ring to the required size and using torch and thin
wire to fill the gap by melting small amounts of metal and fusing
them
with the ring a bit at a time. In this way you do not even have to
cast a sizing section, and it would guaranty solid fusing through out
the cross-section. It would be like sculpting using the torch. If you
never did it before, practice on some scrap prior.

That said, I do not understand why the ring is not stretchable. You
should be able to increase the size of the ring by careful forging
with cross-peen hammer. Try to anneal the ring before stretching it.
Remember, to anneal platinum, one must bring it to bright orange and
keep it at that temperature for at least 30 seconds.

Leonid


#5

what type of gas or fuel are you planning to use with that torch ?
it makes a difference ! your query is right in line with the
mallability of the palladium prong thread that is being discussed
right now the issue of carbon binding. This would be about the only
time in my shop that i could tolerate one of those water torches
(hydrogen flame) that were all the rage about ten years ago now you
see them only here and there. i looked into bottled hydrogen just to
consider the feasability and came within a frog hair of being
reported to the terrorist watch list. ive had success in the past
with acetlelyne flame and my smith little torch being VERY carefull
to use AN EXTREEEEEMLY SHARP OVER OXEDIZEING (sp?) BIG FLAME feeding
a piece of plat. stock as it were a filler rod for a pipe weld

goo


#6
getting full penetration in the weld without melting the edges of
the ring. 

My, Neil, aren’t we ambitious! There are two ways to weld anything.
There’s what you might call light welding, where you put two pieces
together and just fuse them. Then there’s what you need to do -
what’s I believe called fillet welding. It is theoretically possible
to just fuse your sizing, but for a good weld the metal should be
actually fluid. If you do that with your job there’s a good chance
the weight of it will just make it slump or even drip off. What you
need to do is have a triangular shaped space in the joint - miter
one or both sides, somewhat. Then fuse it at the bottom of that
space - I’d fuse one side in place and then go to the other side, so
nothing moves - tack welding. Then fill that space with metal from
the bottom up, making sure that everything flows well as you go. In
other words, don’t expect to just melt the whole seam at once, just
make a puddle and then fill it more and more with platinum rod. When
you file it down, if there’s some pits just use a tiny bur to clean
them out and then re-fuse them. It’s going to be tricky and hot…

http://www.donivanandmaggiora.com


#7

In regards to resizing platinum.

If the band is plain and there are no large stones set into the top
of it I would and have many times fused platinum over the band
without cutting it at all. Efectively making it thicker. Then I use
this metal to hammer down onto and tap the band up. If it coming
close to size and the band is thinning out its too easy to repeat the
process with a little more platinum and rehammer to shape and size.
Viola.

Good luck.


#8
That said, I do not understand why the ring is not stretchable 

There are some ‘anomalies’ inside the ring that trouble me. namely a
good sized pit and this weird groove. If they are flaws in the
original make of the ring or subsequent repair, stretching or
forging may cause me more trouble than I care to have. The ring is so
thick I doubt a ring stretcher would work in any event.


#9
smash it with a hammer on the mandril. 

Does that work for emerald setting too?


#10
I have to size a gent's plain plat wedding band two sizes up, not
stretchable. The cross section is roughly 3 x 5mm.

Can you not order plat in this size? I size platinum rings everyday
and have always ordered the size I needed or would take 2 or 3
sections and weld together. Use seamless solder only. I have 2
torches one Large for jobs like this. The little torch will not work.
Hope this is helpful.

Eric


#11

Another tirck to aid a wide welding seam in platinum is:

As has been stated already, prepare the seam with “V” notches on
either side of the split and have some fill wire (in the case of a 5
x 3 mm band-about 20 gauge round would be appropiate) at the ready.

Now here’s the trick: Roll out very thin (about 30 gauge) a piece of
pure platinum, spread open your prepared seam and slip this piece
into the seam. The piece should be sized, in this case, to be about
1mm larger than the metal remaing after preparing the seam with the
notching. As the weld begins, the pure platinum will melt at a very
slightly lower temp than the platinum alloy of the ring allowing a
weld that easily penaetrates to the center of the seam without
notching deeply. Use a slight swirling motion of the flame’s cone to
stir the now melting metal for the weld to mix both sides of the seam
and the pure platinum together and continue the weld uising the fill
wire until the notches have been filled all the way around the shank;
I always over fill the joint slightly. If you find any voids in the
weld, fill them before finishing the surface, then use a tungsten
carbide burnisher on the weld to comress the joint and any unseen
voids prior to filing and sanding. Repeat the fill welding as
necessary to eliminate and pits, low spots, etc, then go on to the
usual finishing steps.

Credit for this trick goes to “Doc”, United PMR’s metalurgist.
Thanks Doc, I’ve been using it for the past 6 or so years since you
told me about it.

Paul D. Reilly


#12
smash it with a hammer on the mandril. 

Does that work for emerald setting too?

You said plain heavy wed. I never solder a platinum ring shank I weld
all the time, use a small hammer for finer shanks to compress your
weld, soft stones require care or removal.

Allan Creates
www.superringfit.com


#13

Neil,

I don’t think I’d even try to weld Platinum that thick any moRe:
pretty sure the ring will start to melt before you get anywhere near
that deep a weld. I’ve used PMWest’s plumb platinum solders for
several years now (usual disclaimer) and have sized some big Pt with
very good results. You can contact them @ (800) 999-PLAT.

Bruce Morrison


#14
I have to size a gent's plain plat wedding band 

A short life lesson for all.

Years ago somebody was stopped in New York City and was asked how do
I get to Carnegie Hall from here?

Reply was: practice, practice, practice.

Allan Creates
www.superringfit.com