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topic 4530

How to do Electroforming to make gold jewelry




An ongoing discussion from 2000 through 2014 . . .

2000

Q. I am looking for information about gold electroforming for coping with my senior project. I am so interested in this approach, please help me.

I hope to receive good news from you. Thank you.

SOIWISA SOIKUM
student - Thailand


2000

A. Hello, Soiwisa.

Electroforming is essentially the same thing as electroplating. It is called electroforming rather than electroplating when an object is actually made by the electroplating process. For example, hollow gold jewelry may be made by electroplating gold onto a core of wax and then dissolving away the wax, leaving just the hollow gold object. Because the electroplated layer comprises essentially the whole object that has been formed, rather than just a plating on the object, it is called electroforming.

As in the rest of life, there are gray areas: some would call gold covered flowers and leaves "electroformed" whereas other people might call them "electroplated", depending perhaps on whether they feel the gold coating on the flower shape, or the flower itself is the principal object.

Nor should we imply that electroforming is exactly the same as electroplating because certain practical problems begin to arise as the coating get very thick, that may require adjustments in chemistry, operational parameters, and methodology.

Ted Mooney, finishing.com Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



(2002)

Q. I would like to know in detail regarding the principle, process, technique, machinery required (with detailed specifications and budgetary requirements) of GOLD ELECTRO FORMING for Jewelry. Kindly provide me the details.

Thanking you,

P.S. Robi
Indian Institute of Technology - Guwahati - Guwahati, Assam, India


(2003)

Q. I am 17 years old and have been cutting Australian Opal for the past 4 years. Currently I can put opals into jewelry that has been pre-fabricated however I have been unable to set freeform stones. I have been really interested in the electroforming process and I have been desperately searching for more information regarding the process.

David Dawson
Downunder Gems - Perth, Australia


"Electroplating and Electroforming for Artists and Craftsmen"
by Jay H. Newman

from Abe Books
or
info on Amazon

A. Hi P.S., hello David. Technic offers the entire process and equipment for electroforming of hollow gold jewelry. Beyond that, a search of the plating literature will reveal dozens of technical articles on electroforming. There are a number of books on electroforming =>

Good luck.

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey



To minimize your searching efforts and to offer multiple viewpoints, we've combined some threads into the dialog you're viewing. Please forgive any resultant repetition or failures of chronological order.



Electroforming of gold jewelry

2004

Q. WE WANT TO DO ELECTROPLATING ON NONCONDUCTIVE SUBSTANCE. IT IS REGARDING WAX PLATING. KINDLY GUIDE ABOUT CHEMICALS REQUIRED , NAMES & AVAILABLE FROM . THANKING YOU.

NIREN MADHUBHAI SONI.
GOLD JEWELRY - RAJKOT, GUJARAT, INDIA


A. Hi, Niren. For a general introduction,please see our FAQ on plating of non-conductors. But electroforming of hollow gold jewelry is a well developed technology, and Technic is a principal manufacturer of systems and chemistry for this. I have seen published articles on the subject by them and I'm confident that they can both supply and guide you. Good luck!

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


Jewelry artist wants to electroform on opals

2004

Q. Greetings,

I have been cutting opal for years and was thinking about trying to electroform some of my freeform shapes.Can you give me information on a good system to buy and how do you attach a bail if you wanted to make a pendant.Any help on this would be great.

Thanks,

Seth Griffin
Opal Cutter - Copperas Cove, Texas, United States


2006

Q. Dear sir,
I would like to know in detail regarding the principle, process, technique, machinery required (with detailed specifications and budgetary requirements) of GOLD ELECTROFORMING for Jewelry.

Kindly provide me the details.

Thanking you,

Peter P. Rebeiro
- Mumbai, Maharastra, India



Electroform gold jewelry products around the stones in place

2007

Q. I am a product developer in the field of fine jewelry. We have been using 14K cold bath process in which semiprecious stones are set in wax mandrils, masked and then electroformed to set stones in place. Do you know whether a USA patent for stone setting in electroform skin is already published?

Reuven Azachi
product designer - New York


2007

A. If any reader knows that this to be covered by an extant patent and wants to point you to it, or alternately if they can point to early literature to help you make a case that it is public domain, they're welcome to respond, Reuven. But this is a situation where you probably should retain a patent attorney rather than proceeding based on an informal survey. Good luck.

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


2007

A. I remember a similar process in use at Engelhard (UK) about 25 years ago and I have seen jewellery made by this method on sale here.

geoff smith
Geoff Smith
Hampshire, England


Electroforming classes/instructions in 18K for jewelry business?

July 20, 2011

RFQ: We are an established jewelry business in NYC interested in electroforming due to the increased price of gold. Could you recommend someone in the NYC area that can be of service to us in this area of expertise.

Kind regards,

Christina Hunt
jewelry - New York, New York, USA
^- Sorry, this RFQ is outdated
     View Current RFQs




Electroforming the edges of gems, stones

October 12, 2011

Q. I'm interested in 24 kt gold electroforming just the edges of semiprecious stones, shells, rocks. Is there a guide that tells me which of these might react to the acid solution? Or a source that tells me what to coat the areas I don't want electroformed so they don't get acid etched?
I have a small electroforming kit that I know I can electroform the whole organic item with but I just want the edges w/ an attached jump ring for my jewelry.
thanks

Jeanne Millman
hobbyist jewelry designer - Palos Verdes, California, USA


"Jewelry: Concepts and Technology"
by Oppi Untracht

from Abe Books
or
info on Amazon

October 21, 2011

A. You can use bronze powder mixed with diluted nitro lacquer,that is simple DIY conductive paint. Paint it on parts that you want to cover, but you must know that porous precious and semi-precious stones (opal, turquoise, jade, lapis, etc.) are very sensitive, so you must protect them with some protective coating. You can find detailed description of process in any better modern jewelry making handbook (Oppi Untrachts is the best) =>

Hope it helps and good luck!

Goran Budija
metals conservator - Zagreb, Croatia



October 18, 2013

Q. What kind of anode is used for 18k gold electroforming Process.

T Ranjith Kumar
diamonds & jewels - Coimbatore, TN, India


October 18, 2013

A. Hi, T Ranjith. If you are buying a gold plating process, the technical data sheet will tell you. If you are homebrewing, you can probably use stainless steel anodes if it's a cyanide process, but platinized titanium is the safe bet because they work with any gold plating process. Gold anodes would probably work, but are obviously unaffordable. Good luck.

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


October 25, 2013

Q. Thanks Ted for your helpful information. Can you tell me pH value for the electroforming solution I use? 15 gm of GPC and 2 liter of electroforming solution. And how to calculate the gold that coated on the mandrel, using ammeter and amp-hour meter?

Expecting your help and reply

Thank you

Best Regards,

T Ranjith Kumar
diamonds & jewels - Coimbatore, TN, India


45300
October 28, 2013

A. Hi again. If you are home-brewing rather than purchasing a gold plating process, I am reluctant to offer snippets such as "ideal pH" because there are many different baths operating at different pHs, and you should have access to authoritative references like Reid & Goldie's "Gold Plating Technology" , which has a 15-page chapter just on the extra issues involved in electroforming gold compared to electroplating it =>

I'm not really following, though. How are you getting 18K, and what are the 6 missing karats comprised of? What else is in your solution besides GPC? Forgive me if I am misreading, but it sounds like you are doing or expecting to do gold electroforming from a bath with nothing but GPC and water in it?

Can we please restart this discussion with you answering the implied questions of whether you are purchasing an 18 kt gold electroforming process or trying to design a gold plating solution, and how much success you've previously enjoyed in gold plating and electroforming so we can appreciate the context behind the questions? Thanks!

Regards,

Ted Mooney, finishing.com
Teds signature
Ted Mooney, P.E.
finishing.com
Pine Beach, New Jersey


November 11, 2013

A. Ranjith, Firstly, gold deposition follows Faraday's Laws of electrolysis, so 7.35 grams of gold are deposited every ampere-hour (3,600 coulombs). Secondly, before you start electrodepositing gold from a cyanide bath, please get some professional training -- cyanide is extremely poisonous and you run the risk of killing either yourself or other people. You must use the correct safety equipment as well as have a process tank that is safe to use with cyanide.

I also suggest you buy a commercial electrolyte and precisely follow the operating instructions, otherwise you will be spending a lot of money on expensive gold solutions and not get anything to show for your investments

trevor crichton
Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK


November 12, 2013

A. Sorry to disagree, Trevor, but there are other important issues.
Few gold plating solutions are 100% Faradic efficiency. Pure cyanide golds run at about 90-95% while acid hard golds are 75-80%. A home brew could be even less. This is not the solution failing to comply with Faraday but other reactions account for the missing current.
There is a further issue in calculating thickness from the weight. The density of pure gold is given as 19.3g/cc
Electrodeposited gold has a modified crystal structure and includes co-deposited organics - typically cyanide polymers.
The actual density is about 17g/cc but again will vary with the solution type.
I have electroformed gold to well over a mm and these considerations make a big difference.

I do however agree completely that home brewed gold solutions are a complete waste of time and money.
It is also true that we should be doing all we can to discourage amateur use of cyanides. Accidents give the entire industry a bad name.

geoff smith
Geoff Smith
Hampshire,
      England



November 13, 2013

A. Hello,
Just a few notes that may help with Rajith's question in late October. There are problems that arise when using a 2 liter gold bath, especially for electroforming. This is especially true if the bath will be used repeated times. When you weigh out 15 grams of PGC there are only a little over 10 grams of gold metal in the bath. Also to be able to give an exact amount of gold deposition is very difficult because there are many factors that control the deposition rate. Some of these factors are; metal concentration, temperature, ph, solution agitation, other bath additives such as conducting salts, whether they be citrate or cyanide based. The trouble with plating with very small solutions is that the bath is taxed rather quickly and frequent additions must be made to maintain proper gold deposition rates. There are plating charts that will give you deposit rates that are close. This is why the charts have footnotes such as "at 1 troy oz metal per gallon, @ 5 ASF, and 45 or 50% current efficiency. Conditions of the bath have to be ideal to match the numbers on electroplating charts, or data thrown out there without proper "applied conditions" attached. I strongly agree with Geoff and Trevor's advice regarding cyanide.

Mark Baker
Process Engineer - Mesa, Arizona, USA



November 15, 2014

Q. Hello
I want to do gold electroforming. Please tell me about all of materials that are used in solution of electroforming.
I am not a professional so please tell me step by step about solution and temperature and conditions of gold electroforming.
Thanks alot

Maryam Bastanirad
- Tehran-The Republic-IRAN


December 27, 2014 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread

RFQ: Hello, I came across electroforming technique but it seems very difficult to get into workshops or courses on the topic, I would like to know if anybody could suggest or recommend either a service or professional in or around NYC.
Thank you ,
Anna Sterlikova

Anna Sterlikova
Jewelry designer - New York, NY USA



March 27, 2018

Q. Sir, please tell me what is the value of surface area for electroforming and how we get it per piece surface area -- what is the best trick?

shubham maurya
- ambedkernagar,up,INDIA


March 2018

Hi Shubham. I don't actually know of truly worthwhile "tricks" ...

rochester_book
I've heard of people measuring the dragout from unknown surface areas, then comparing it to the dragout from known surface areas, but there are enough complicating and upset factors, as described in Chapter 5 of Kushner's "Water and Waste Control" that I don't think this method is robust at all. You can also compare the current drawn at a given voltage to the current drawn by a known surface area, but again this brings complications, and would probably be useful only to someone with broad experience in that art. Employing Faraday's Law is another probably weak approach. Plating parts with electroless nickel, and weighing the deposit is still another such surface area estimation method.

Tom Rochester offers a book, "Surface Area Formulas and Tables" with a lot of helpful tabulated data and mathematical formulas, which also addresses the strengths & weaknesses of such "tricks". Good luck.

Regards,

pic of Ted Mooney
Ted Mooney, P.E. RET
finishing.com
Pine Beach, New Jersey
Striving to live "Aloha"


March 28, 2018

A. Hi Shubham

Two thoughts.

Make a guess and plate a sample. Note the time and current.

Weigh the electroform and measure the thickness. Make any correction for Faradic efficiency (acid copper needs no correction). You can then make a reasonable estimate of the surface area.

The simplest case is where the part is made to a computer designed drawing. Most CAD programs will calculate the surface area for you and any designer should print this on the drawing.

geoff smith
Geoff Smith
Hampshire,
      England




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