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Help with gold electroforming




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Gold electroforming baths which can operate at room temperature

Q. My best regards to Mr. Ted mooney and all plating colleagues.I am used wax as mandrel material to produce different products from silver electroforming bath which work at room temperature and I am succeeded. Now I want to prepare a gold electroforming bath which operate at room temperature or less than melting point of wax mandrel [60 °C]. I would like to be able to electroform to 800-1000 microns. Bright finish is not necessary because I am use a negative mandrel in my process and it is simple to finishing. Can anyone help me? what formulas, what the operating conditions, pH value, and type of anodes?. No problem if the formulas for application of alloy or pure gold plating.

Thanks,

Aide Mohhy Enad
plating shop employee - Baghdad, Iraq
2007



"Gold Plating Technology"
by Reid & Goldie

on AbeBooks

or eBay or

Amazon

(affil links)

A. Dear Enad,
I feel it would be better for you depend on supply houses for this process. I know that suppliers have this process which gives as much as 106 mg/amp/minute.
Regards,

t k mohan
T.K. Mohan
plating process supplier - Mumbai, India
2007



2007

thumbs up signDear Mohan,
Thank you for participating but you must know that most of these chemical compounds I need prepared myself from individual chemicals to lower cost, and for the difficulty of importation to Iraq.

Best regards,

Aide Mohhy Enad [returning]
- Baghdad, Iraq


A. Cyanide gold chemistries are common for electroforming gold alloys and are operated at 55-65 °C but lower temperatures can be used adjusting the amperage down correspondingly.

Guillermo Marrufo
Monterrey, NL, Mexico
2007



sidebar notes

Q. My best regards to all plating colleagues... [Ed. note: same question as in 2007]
Thanks.

Aide Mohhy Enad [returning]
Plating shop employee - Baghdad, Iraq
January 24, 2009



A. I know very little about gold electroforming and am not going into details and formulas, but I must inform you the melting temperature of wax is not limited to 35 °C. There are several waxes that go up to 50 °C and more. So, don't worry much about operating temperature.

Guillermo Marrufo
Monterrey, NL, Mexico
January 28, 2009


A. Conventional waxes used in electroplating have a melting point of 75-80 °C so electroforming solution does not need to operate at room temperature.

dayton dailey Dayton Dailey
supplier
- Lake Zurich, Illinois USA

January 30, 2009




Q. My best regards to all plating colleagues... [Ed. note: same question as in 2009]
Thanks,

Aide Mohhy Enad [returning]
Plating shop employee - Baghdad, Iraq
May 23, 2013


A. Hi, cousin Aide. The Metal Finishing Guidebook has a very good chapter about gold plating, which will answer many of your questions; see if you can find an old hard copy, the older the better, because the older the version, the more generic all of the the articles.

It's not that people don't want to help you, cousin, but in most of the world today, gold electroforming baths have been almost exclusively proprietary for decades. That means that: 1). most of us don't know how to formulate one from scratch, or 2) for those who do know, it is either their company's trade secret or they are afraid to reveal it for fear of blowing someone else's trade secrets. Even the current literature for the most part doesn't tell us how to formulate plating baths anymore :-(

Your question is welcome, but you have posted it 3 times now, and several people have offered solutions even if not precisely on target for you :-)

Good luck and Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
May 26, 2013




Q. Hello,I hope one day to find some company that does service of gold and silver electroforming for hobbyists (preferably in Italy) but before I would like to know if anyone knows the melting points of 18Kt gold electroforms (solidus and liquidus), is it more than 900 °C so granulation can be later applied? Thank You

Miroslav Tadej
- Zagreb, Croatia
August 2, 2008




Neutral make up bath formula for 24K gold electroforming?

May 30, 2008

Q. We are the manufacturer who produces 99.99% gold statues by electroforming process.
I would like to study the 24K gold neutral electroforming bath. The current electroforming bath we use is supplied by importers, so we have no ideas about what are the basic ingredients of the conductive salts. It is a great problem since we do not have trouble-shootings from our supplier, every solution we had towards the past problems is from our "experience"! So I am looking for a more scientific way to create a better trouble-shooting table for our production line by using "numbers".
The study of the contribution of each basic component/conductive salt might help me to determine the length of this neutral electroforming bath's life since its aging process is unclear to me. The gold thickness serves a crucial point for the decorative statues. The price is better when the weight of gold is lighter. But when the layer is thinner (the weight is lighter), the structure is weaker (softer). The gold salt content and the conductivity of an existing bath affect the gold electroforming deposition rate.

Would it be a citrate bath or a phosphate bath when the bath pH is 6 or 7?
What's the theory we have for the additives that make the electroformed gold have a velvet/satin surface?
I appreciate very much if you could answer my question.

Y.H. Wahlberg
employee - Xiamen, China



May 2008

thumbs up sign Hi, Y.H.

I can't answer, so all I can do is philosophize :-)

In the days before a global economy, the theory was that a supplier could invest man-years in research to develop optimum formulations for a plating bath, and then offer the process complete with hands-on technical service and convenient access to analysis to numerous shops. In this way the supplier could keep the formulation secret, and get a good return on his development investment, and the shop using the process would be able to function just fine without needing to know the details of the formulation.

If we expect that to work for you, you obviously must have technical service from the supplier and they must offer a convenient analytic facility. If you cannot find such a supplier, we all have a problem. Although you may lack the supplier's tech service and analysis, no one can share these trade secrets with you so you'd need to independently duplicate those years of development effort (not very practical).

It's a genuine problem for you, but it's an interesting thought experiment for the rest of us to try to figure out a viable business model :-)

Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey



simultaneous replies May 30, 2008

I have never done gold plating, so can not answer that question. I used proprietary material when I could, just because of startup and trouble shooting, so I agree with Ted on that.
In your case with no tech service, there are many books on electroforming and there must be at least one book that has formulations you could do a pilot plant operation on to see if it was practical.

I would not jump into it before several weeks of pilot plant trials. Lab trails are not a great indicator of problems that will pop up on the line.

James Watts
- Navarre, Florida



June 1, 2008

Dear Mr. Mooney,

Thank you for your answer.
My questions sounded stupid, I know I almost made myself sound like a person who attempted to dig out people's secrets (equivalent to committing a crime).
There are not many choices there, citrate or phosphate?
Could you or anybody just pick one?

Best Regards,

Y.H. Wahlberg
- Xiamen, China



June 4, 2008

thumbs up sign I saw nothing wrong with your question at all, Y.H. You find yourself having understandable problems trying to do electroplating with a proprietary plating solution, and wondering how to fix it, and nobody is there to help you and you don't know what is in the solution or how to adjust it. I am just saying that the traditional answer and the better answer if possible is for the supplier's tech service team to come on-site and get it fixed for you.
Sorry, I don't know much about gold electroforming and really can't offer formulation advice, but hopefully another reader will be able to suggest whether citrate or other formulations are most promising. Good luck.

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey




Q. What is the complete mechanism of electroforming of gold? Please with video and pictures. Thanks.

Farzad Farahad
- Tokyo, Japan
March 19, 2013



"Gold Plating Technology"
by Reid & Goldie

on AbeBooks

or eBay or

Amazon

(affil links)

A. Hi Farzad. Please try contacting companies like DeGussa and Technic. They are quite involved in supplying equipment and processes for gold electroforming, and may be able to send a brochure, and maybe even a video.

There are videos on youtube and elsewhere; I think this is one of the better ones for an overall introduction, although it's directed at individual jewelry artists and hobbyists rather than high production factories:

She makes some good points that I had never spent much time thinking about. Good luck.

Regards,

Ted Mooney, finishing.com
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 23, 2013




How to replace cadmium in alkaline cyanide baths ternary alloys (Au-Cu-Cd)?

Q. Hello
I'm from Brazil and here we still use thick coatings of gold for decoration. For more than 15 years we successfully used a formulation, sold here, derived from a German industry (DEGUSSA) to cyanide alkaline baths for hard and thick layers in alloys 18k (Au-Cu-Cd). This alloy has 75% Au, 19% Cu and 6% in Cd. Thinking to meet the most demanding markets such as the US and the European bustamos a new formulation without cadmium. Because with the current formulation we cannot meet the laws of those countries.
So everything that ever expose above, I would ask if anyone knows any alkaline process, efficiency of quick deposit, which can be a bright layer, uniform, with gold alloy alloy (18k) for use in jewelry?
I know that ninety percent of companies use the lowest possible layer and protect cataphoretically with varnish. That is not our market. We want to find some way to continue with thick deposits, but without cadmium.

If someone can help, I thank you.

Paula Bardini
- Sao Paulo, Brazil
February 23, 2015




Q. Hello,
Could you please help me to solve my problem? I made electroforming of gold by using mandrel alloy and gold electroplating bath. Everything went well but when I emptied the mandrel alloy by using furnace, the gold piece was brittle and broke very easy ?
Thank you so much

Mansour Abdelkader
Employee - Cairo- Egypt
January 10, 2019



April 12, 2019

Hi Mansour,

Is your gold plating bath contaminated with metallic impurities to cause gold alloy deposit with poorer ductility than pure gold?

Are you applying too high current density?

You may add arsenic trioxide as grain refiner and do annealing after gold plating to overcome brittleness.


Regards,
David

David Shiu
David Shiu
- Singapore




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