Electroforming sterling

I’ve just discovered this wonderful resource and am thrilled. I’ve a
background in sculpture, and am also a certified jeweller [years of
selling antique pieces]–but have only recently melded my passions.
Now I can’t imagine what took me so long; I’m happily obsessed.
Having looked at the calibre of work in the orchid gallery, I know
that sentiment will resonnate…

I have a technical problem: I am one tiny step away from completing
a complex fabricated piece in sterling. Unfortunately, I’ve been
unable to place the superfine antennae; can’t build up enough heat in
the [solid] little bee heads to draw the solder down into the seating
holes–not without melting wings, legs, [hollow] beebodies, etc…
Made a couple of Dali-bees before accepting that yellow ochre/heat
shield paper were not going to save me. So, after 2 months of
patience and perfectionism, I had to resort to epoxy–and am
miserable with the results. I have read that one can bezel a stone
in place by electroforming–so couldn’t the technique be used to
build up a bond (and strength) for my antennae?? I’m not eager to
invest in a system for myself [toxic materials]–but would love to do
the ‘set up’ myself and have someone do the forming for me. Does
this sound possible? Reasonable? Although I live and study in San
Miguel, Mexico, I am in Victoria, B.C. (Canada) for the month of
July–so any help ‘close to home’ would be ideal. Though I’d be
delighted with ANY help or suggestions from anyone, anywhere.

[an aside: any opinions on the Daniel Brush book? I’ve just ordered
it–anticipate being blown away.]

Many thanks.
Andy (c/o @Gordon_Green)

Have you though about drilling and tapping holes, then using the
appropriate die, cutting threads on the antennae? A little
"lock-tite" and screw them in place. If you like, nick the base of
the antennae, right where the threaded pieces come together with a
graver, and they’ll never come out.

David L. Huffman

You might want to look into a small resistance welder.

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Silverfoot-

Andy,

I had a similar problem (different insect!) and thought about a great
deal… I came up with drilling holes for the “antenae” wires that
needed to be soldered onto the head. I thought I would “tin” the ends
of the wires, plug them into the holes, and put the whole job into
the oven to solder it…

Then while I was preparing to do this (and naturally it was Christmas
rush!), I came up with a faster way. I simply drilled the holes and
tapped them! Threaded the “antenae” wires, and screwed them in…

I’m sure the first method would work for finer wires - but I was
using 22 gauge, and the taps & dies were handy on the bench from
making a special set of platinum screw backs for earrings…

Now, making moveable wing joints is a bit more complicated…

Brian P. Marshall
Stockton Jewelry Arts School
704 W. Swain Rd.
Stockton, CA 95207
209-477-6731 Office/Fax
209-477-6535 Workshop/Classrooms

Andy–It would help to know what gauge wire you are using for the
antennae. I’ve made a lot of insects with rather thick, cast bodies,
and usually have been able to drill a hole and insert the wire. I
use a wire longer than I will need, so it goes through the hole and
can be soldered from the bottom. Melt the solder on the insect
itself first, then just heat it enough to run onto the wire. Then
trim the wire flat. Sometimes I isolate the more delicate parts
(wings, legs, etc.) by placing each end of the bug on a separate
piece of charcoal with a space in-between and/or putting a clamp or
tweezer on to act as a heat sink. I also at times have used Ochre
AND something like Kool Jool, or another heat retardant on the rest
of the piece. I have found the soldering somewhat easier to do since
I started using a Little Torch. I have also found at times that I
simply cannot use as fine gauge wire as I would like, and will either
adapt the design to a slightly thicker wire, or twist two fine wires
into a very tight twist. If the antennae are fairly long, they need
to have some strength so they do not bend or break too easily.

I hope this is helpful. If you would like to talk more about making
insects (my favorite thing) please contact me off line. Best Wishes
Sandra (Elegantbee@aol.com)

   I have read that one can bezel a stone in place by
electroforming--so couldn't the technique be used to build up a bond
(and strength) for my antennae?? 

Sounds good, but in practice, this may not be the best way for you to
do it. electroforming in silver, first off, is not as easy as, say,
doing it with an acid copper bath. You’ll be mucking around and
spending cash quite a bit to get the process just to give you a nice
deposit before you can even address your specific need.

Plus, remember that electroforming, like electroplating, acts most
strongly on the most exposed areas of a piece. Getting good
deposition in a crevice is quite difficult, as the metal wants to
deposit on the ridges. What will tend to happen is you’ll build up
lots of silver on the antenae themselves, especially the ends, with
little if any deposition down near the joint, since the extending
wires will draw the current away from those areas. So then you stop
it all off with resist, leaving only those little areas exposed…
But even this isn’t as simple as it seems, since cyanide silver
solutions are rather good cleaners, and getting a resist to stay long
enough to electroform a substantial amount of metal isn’t so simple
either. Even then, you’ll got no deposition down within a seam such
as solder might do, but will build up only on exposed surfaces. This
might be made to work, but is it what you want?

It seems to me that a simple solution would be to use a different
technology to perform the soldering operation, which is still
basically what you wish to do, after all. Since getting around the
heat sinking ability of your bee’s body without melting the find parts
is difficult to do with a torch, try using a kiln. Paste solder is
probably the easiest to use, in a grade easier than those used to
solder the rest of the item. You’ll need some sort of fixture that
can hold parts in position, perhaps made from soldering or casting
investment. Then place the piece, properly fluxed or with the right
paste solders applied where needed, in the kiln, and fire it only to
slightly above the flow temp of the solder. This way, the whole piece
is heating evenly, nothing can melt but the solder, and when it’s
cool, you should then have a good and well soldered joint. and a kiln
capable of doing this will be cheaper than setting up an
electroforming tank by far, as well as safer to use. Then when
you’re done, if you like you can use it for enamelling too.

Kiln soldering, while less used by individual craftsmen, is the way
many jewelry parts, especially gold ones, are assembled in industry.
And it’s also remeniscent of the way things were often soldered back
before the development of torches in the first place. If you can
modify your kiln to give you consistant reducing atmospheres as well
as controllable temps, you could even assemble a thing such as your
bee entirely without actual solder, using granulation techniques.
Consider all the fine ancient granulated jewelry in gold, mostly, that
attached superfine constructions of wire and filligree, often to
heavier suppoert structures of one sort or another, with sufficient
strength to hold up just fine over the centuries, yet without actual
solder, or sometimes, even visible joints. Those things were fired
just over charcoal hearths of one sort or another. Even slow heating
gets around the fact that fine parts heat faster than thick ones…

Peter Rowe

Hi,

I have experimented with electroforming bezels around stones and
plating flowers/leaves etc. with success (copper though). I also
happen to live in Victoria B.C. If you would like to contact me off
line I can loan you a book on electroforming using the Dalmar method.
I t also explains the equipment and other items required to get
started.

The main thing with electroforming is that the method is limited in
how far it can “throw” material across a non-conductive void. If your
joint between the antennae and the head is tight you might be able to
build up material to secure it.

Cheers,
Cameron Speedie
Island Gem and Rock
@Islndgem

     If you can modify your kiln to give you consistant reducing
atmospheres as well as controllable temps, you could even assemble a
thing such as your bee entirely without actual solder, using
granulation techniques.  

Peter,You have always been so helpful in so many ways to all of us
that I would like to express my gratitude for all the and
tips you have given. I know how much time it takes to detail all the
stuff you share with us. So a great big thanks.

I would like to modify a kiln I have to enable kiln granulation, so
if you have that I would sincerely appreciate your
guidance in how to accomplish it. Thank you Joe Dule

 I would like to modify a kiln I have to enable kiln granulation,
so if you have that I would sincerely appreciate your
guidance in how to accomplish it. Thank you Joe Dule  

Joe, I’ve not actually modified a kiln to do this, myself. But what
you’d need to do is somehow feed in a sufficient quantity of reducing
or inert gas of some sort, to force oxygen/normal atmostphere out.
This is much the same as the gas shielding that is done in many types
of welding, for example, or with some of the higher priced vacuum
casting machines, which feed inert gas into the crucible where it then
covers and protects the melting metal.

Industrial soldering furnaces include a device to (electrolytically,
I think) “crack” ammonia into a nitrogen and hydrogen mix. The
hydrogen therein is a powerful scavenger of oxygen. But an ammonia
cracking unit is overkill for your use. You can obtain, from any
welding gas supplier, so-called forming gas, which is a similar mix, I
think. Or there are various mixes available of argon and carbon
dioxide, or other such shield gases with similar uses: that is, to
protect hot metal from oxidation. The gas supplier can discuss with
you the pros and cons of each type of gas. A regulator/valve
arrangement of some sort to adjust/control the rate of gas flow would
be needed, and then you’d simply run an external line from that tank
into the cavity of the kiln. gas flowing in should then expell the
existing atmosphere, if the kiln is otherwise reasonably well closed.
You might have to play with changing the venting arrangements of the
kiln to keep a uniform atmosphere in the kiln. The placement of the
infeed tube might have to take into account whether the gas mix used
would tend to sink or rise in the kiln. Again, depends on how high a
gas flow is needed to keep the interior of the kiln free of oxygen.

All in all, this should not be especially hard to rig up. The
systems used to shield melting crucibles in the casting machines that
do so, are quite simple. No reason to do more than that here. And in
use, you’d simply then test it and work out the needed gas flows by
experimentation to see how much is needed to get the job done.

However, do take the time to ask yourself whether you need to do
this. Other soldering technologies exist which also deal with the
problems of oxidation. We call them fluxes… You can solder in a
plain old kiln, oxidizing atmosphere and all, if the seams are
properly fluxed to protect them from oxygen… With golds, plain old
boric acid and alcohol is likely all you need apply. And part of the
key to granulation, as it’s normally practiced, is that the chemicals
used to adhere the grains will also supply the needed protection in
the form of carbon, which creates the needed reducing atmosphere at
the contact points, allowing fusion of the grains regardless of the
atmoshphere around them. Alternate recipies could simply include a
trace of flux. Not enough to float the grains, but enough to protect
the grains enough to allow fusion…

Try it. I suspect that you should be able to granulate in a kiln
without needing to go to the bother of modifying a kiln with a shield
gas. I mentioned the possibility simply because it’s there, and might
make higher production rates possible, since with a good shield gas,
one might not need the chemicals at all, aside from something just to
hold the grains in position after they’d been copper plated. And it
then saves the surface finish of the work from oxidation and sometimes
the need for subsequent pickling.

Hope this helps.

Peter Rowe