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Electroforming


#1

G’day: I find it almost impossible to keep my nose out of
things: so here’ my small addition. Quite a while ago I dabbled in
the art/science of electroforming. I tried mixing copper filings
with varnish but although I got a plate, it was patchy. At that
time there used to be a graphite, water-based colloidal
lubricant for machines and cars on the market called "AquaDag"
This was fairly thick, but could be diluted with a small amount
of water and painted on the object to be formed - in my case, a
series of fresh-cut leaves from NZ trees. The leaf was cleaned,
coated with AquaDag and dried in a warm place. (the airing
cupboard, but don’t dare drip the graphite on the clean linen!) I
used a copper cyanide solution, the power source was a car
battery charger with fine control of the current via household
light dimmer on input and a 0-250 milliammeter in series in
output. The coated leaf was connected by means of a crocodile
clip to the negative pole of the charger and a piece of copper
sheet to the positive pole. I soon discovered that a low current
gave a good dense, nonporous plate which could be built up over a
period to be 0.5 mm- or more. I also found that it was necessary
to stir the bath constantly, but best results occurred when I
was able to slowly rotate the leaf. The leaf, of course was still
inside the copper when done. The same method worked for silver,
and I silverplated previously plated copper ones too. (a miserly
fellow, eh?) The thin coating of graphite worked very well, but
at first a fairly high current was needed but as soon as a very
thin plate occurred, the current could be cut right back. Sorry
I can’t tell you details of current, but you’d soon get the idea
with experiment. The cyanide strength is not at all important -
I just put ‘some’ in a vessel and dissolved it in warm water.
Experiment - and don’t be scared of cyanide; just take very
obvious precautions - and keep kids OUT! Oh copper sulphate
solution does give a sort of plate, but you won’t be happy with
it. Cheers,

    /\
   / /    John Burgess, 
  / /
 / //\    @John_Burgess2
/ / \ \

/ (___)
(_________)


#2

The cyanide strength is not at all important -
I just put ‘some’ in a vessel and dissolved it in warm water.
Experiment - and don’t be scared of cyanide; just take very
obvious precautions - and keep kids OUT! Oh copper sulphate
solution does give a sort of plate, but you won’t be happy with
it. Cheers,

Very interesting, Thanks for your input John, I was wondering
if there is diference in plateing and electroforming.
Unfortunatly the school I am going to dose not allow us to use
cyanide. The school dose not have a very strong art department
and only offers one jewelry class, so the students who take the
class potentaly have no experiance with metals or the use of
chemicals. I figure this is probably why they wond allow us to
use the Cyanide solutions. We are luckey to have a teacher who
has a fine arts degree in metal working and also works part time
duing jewelry repare.

Also are there any inexpencive solutions that do not contain
cyanide and cane be used to electroform silver? The cost of the
plating solution that Reo Grand sells is to high. I think it is
somthing like $50 an ounce.

The experiments that we have done so far using copper sulfate
have produced a granular texture as it builds up. Is this
typical, and are there any methodes for achiving diferent
textures?

Isaac


#3

TC> Very interesting, Thanks for your input John, I was wondering
TC> if there is diference in plateing and electroforming.

G’day Isaac; there is little difference in electroforming and
electroplating; in electroforming one simply continues plating
whatever metal one is using until the plate has become
sufficiently thick for what you need.

TC> Also are there any inexpencive solutions that do not contain
TC> cyanide and can be used to electroform silver? The cost of the
TC> plating solution that Reo Grand sells is to high. I think it is
TC> somthing like $50 an ounce.

The reason that Rio’s solution is expensive is partly due to the
fact that silver based chemicals aren’t cheap, though I suspect
suppliers might load up the price a bit. To electroform with
silver I use a cyanide solution bath and use a piece of pure
silver as a positive electrode, and warm the bath a little. I’m
afraid I don’t know of any good replacement for cyanide.

TC> The experiments that we have done so far using copper sulfate
TC> have produced a granular texture as it builds up. Is this
TC> typical, and are there any methodes for achiving diferent
TC> textures?

You will get a plate from silver nitrate, but it will be as
granular as when you use copper sulphate, though you could try an
extremely low electric current to see if that improves grain
size. You would do best by texturing the article after it has
been formed by other methods. I’m afraid that cyanide plating or
forming baths seem to be the best electrolytes. Sorry , but
that’s all I can offer.

        /\
       / /    John Burgess, 
      / /
     / //\    @John_Burgess2
    / / \ \
   / (___) \
  (_________)

#4

Also are there any inexpencive solutions that do not contain
cyanide and cane be used to electroform silver? The cost of the
plating solution that Reo Grand sells is to high. I think it is
somthing like $50 an ounce.

Yes, there are some available that do not contain cyanide. I
have a catalogue from Brownells’, the gun parts supplier. The
gunsmithing and repair profession has a lot of use for plating
though I seem to recall they use a lot of nickel. They were
selling a non cyanide based plating solution. Try them but be
aware they sell their catalogue.

Also try doing a search on the net. I seem to recall a company
offering solution on the web. Might have been advertised in
Lapidary Journal :slight_smile:

Regards,
Peter


#5

Hi John

Thanks for the info on electro forming. Do you think that I

could plate an 8" steel and once copper plated lap using your
system?.

The lap I have in mind is 3/8" thick and is charged with 600

diamond on one side and 1500 on the other, but the copper plating
has almost all worn off. It still works but it is time for
recharging and I would like to do that on a new copper surface.

I am posting this to the net because I think others would be

interested.

If you don't answer the Kiwi's will get you................Leo

#6

Hi,

When I was serving my apprenticeship 30 yrs ago, we would
silverplate dental impressions. The lower the current the finer
the plate. You need to build-up the metal at a very slow rate.
Just for the hell of it I once took a small maple leaf and
coated it with the silverizing solution, put it in the cyanide
solution with the silver anode and turned the current on to a
fine hair above zero. I let it in there from Monday morning
until late Thursday afternoon. The results were so nice that my
damn boss took it and had a jewler solder a pin backing on it
and he gave it to his wife for Christmas! The plater that we
used was a Hanau brand made for the dental industry.

Skip

                                  Skip Meister
                                NRA Endowment and
                                   Instructor
                                @Skip_Meister
                                05/18/9704:13:26

#7

jpp> gunsmithing and repair profession has a lot of use for plating
jpp> though I seem to recall they use a lot of nickel. They were
jpp> selling a non cyanide based plating solution.

G’day; Nickel and chromium cyanides are insoluble. For nickel
plating a thin plate of copper is laid first, then a solution of
nickel sulphate or nickel ammonium sulphate is used, which is
slightly acid, and a nickel or stainless electrode is used. For
chromium a solution of chromic acid and a stainless electrode is
used, with a very high plating current. A thin plate of copper,
followed by nickel is necessary to give a durable non-peel plate
of chromium. Cheers,

        /\
       / /    John Burgess, 
      / /
     / //\    @John_Burgess2
    / / \ \
   / (___) \
  (_________)

#8

G’day Leo, et al. Yes, you could copper plate a steel
lapidary plate, but it is absolutely necessary to strip all the
old plating off first, and the surface must be scrupulously,
chemically clean. Otherwise the plating will be pretty poor.
Incidentally, it is essential to plate steel using a cyanide
bath; if you dip steel into an acid copper bath (copper
sulphate, for instance) you will get an instant chemical plate
but it will have extremely poor adherence. I suggest there are
four options: a) take it to a professional plater and specify
the thickness of copper you need - it shouldn’t cost all that
much. b) get a new lap. c) get a solid copper lap. d) spend
hours messing about learning what you will probably only need
once, instead of making jewellery.

I’m not afraid of the Kiwis: it’s the Moas, the Dinosaur
Tuataras and the Giant Wetas that scare me. Cheers,

        /\
       / /    John Burgess, 
      / /
     / //\    @John_Burgess2
    / / \ \
   / (___) \
  (_________)