NHZ
Harmless
Posts: 22
Registered: 9-8-2011
Member Is Offline
Mood: No Mood
|
|
Help with gold plating?
I recently picked up a plating kit for use in some projects. I needed the thermal properties of gold and plated over freshly machined copper.
I have a couple of gold nuggets collected over the years and would like to make a relatively safe plating liquid.
There was no MSDS or list of chemicals in the solution my plating kit came with.
What are my options to get a decent electroplate from scrap
jewelry??
Thanks.
|
|
|
cyanureeves
National Hazard
Posts: 744
Registered: 29-8-2010
Location: Mars
Member Is Offline
Mood: No Mood
|
|
the wonderful compound of cyanide is the daddy of plating solutions. you will have to separate gold from the other metals in your jewelry by way of
aqua regia and dropping purer gold with sodium metabisulfite. i read that you could boil potassium carbonate with potassium ferrocyanide and auric
chloride and get a gold plating solution. i tried this method with silver chloride and it plated silver just beautifully,it actually takes longer to
tarnish than cyanide silver but of course cyanide is better. i read that you can substitude auric chloride with the red stuff that drops when you add
ammonium hydroxide to gold chloride solution.i have made this red stuff but am too chicken to boil it with the potassium carbonate/ferrocyanide
concoction because gold is just too expensive.all i have is 12 grams of pure gold in a button nugget which i sometimes toss on my bed and roll all
over it and pretend i'm rich.what i have tried was heating potassium ferrocyanide in sulfuric acid and bubbling the hydrogen cyanide gas into
potassium hydroxide/ethanol solution then dried the salt.after the salt was dried i added a little distilled water and electrolyzed pure gold into the
solution using 6volts and a pure gold anode and cathode.i have plated coins this way and s.steel but ammonia base brasso will rub the gold off if i
polish hard.potassium ferrocyanide is safe but can become deadly if you add acids to it.correction: potassiumferrocyanide and acids will produce
hydrogen cyanide but it's up to you if it will be deadly
[Edited on 23-10-2011 by cyanureeves]
[Edited on 23-10-2011 by cyanureeves]
|
|
|
NHZ
Harmless
Posts: 22
Registered: 9-8-2011
Member Is Offline
Mood: No Mood
|
|
The stuff I have works very well and can be applied to the copper
with a q-tip and 12v. The solution appears to be some form of acid / gel,
but also seems to be a very weak acid.
Any ideas what is used for consumer kits? I want to avoid any hazards
like cyanide..
On the same note, I want to make a plating bath opposed to 'painting'
it on with a brush for larger pieces..
Also, I live in Canada, and chemicals like nitric acid etc are next
to impossible for a hobbyist to obtain. Im doing this work at home
and want to keep it as safe as possible.
LOL, scratch the non-cyanide... I just found the same supplier of the kit
I have, they are under a new name.. They indicate the use of
cyanide at the bottom of their page.
Something tells me I will end up sticking with premade kits to
remain on the safe side of things. I am by no means a chemist
and only 'dabble' in certain things which relate to my electronics work..
|
|
|
watson.fawkes
International Hazard
Posts: 2793
Registered: 16-8-2008
Member Is Offline
Mood: No Mood
|
|
I think folks on a jewelers forum
might have better practical answers. Electroplating gold is an ordinary technique for them. Perhaps some of the folks make homemade printed circuit
boards have something they use for gold-plating contacts.
Other than cyanide as a counter-ion for gold, the only thing I know is my ignorance. I understand there are often other additives (including organic
ones) in a plating bath that affect surface finish, but I can't say what they are.
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
