Electroplating

Thread Starter

Mazaag

Joined Oct 23, 2004
255
Hi guys..

I just wanted to ask, what type of chemical would I need to be able to electroplate a metal with Copper?

And secondly, what would happen if i were to replace the DC source with an AC source?

Thanks
 

arthur92710

Joined Jun 25, 2007
307
Or you can use a diode bridge to chage 120vac to 170dc but you will surely get shocked so dont do it (does not matter how carefully you are!!)
 

SgtWookie

Joined Jul 17, 2007
22,220
No, that would be an extremely bad idea.

For the best results, you need to use very low current. High voltage = high current = very poor results.

Experiment using very low DC voltages on a few pieces of scrap. You may find that different materials plate better at different voltages, and with different strengths of electrolyte.

Oh, and if you need something gold plated - take it to a jeweler or someone who specializes in gold plating. The electrolyte for that is cyanide - very easy to kill yourself if you goof up.
 

mrmeval

Joined Jun 30, 2006
833
Copper sulfate commonly called 'root killer' at the hardware store and an acid.

http://chemmovies.unl.edu/chemistry/labs/LABS15c.html

If you skip the acid you will get a coating but it won't want to adhere to the surface evenly. It will be very granular and erratic. I was able to make thin impressions of quarters in some cases but sometimes the copper would adhere. You want a current limited supply and as this particular link states +12V.
 

bloguetronica

Joined Apr 27, 2007
1,372
Besides a copper anode, any copper salt solution will do. Copper cyanide gives the best results (because it also cleans the metal), but is very toxic. You are in certain risk of death if you use it, so my advice, don't.
A very mild solution of sulphuric acid can be used along with the salt dissolved in it, but won't be necessary if the piece is already clean. Though, DO NOT use sulphuric acid if you decide to use copper cyanide, as the acid reacts with it, even in very low concentrations, releasing very poisonous hydrogen cyanide fumes (prussic acid), causing instant death. My advice is, if you decide to take the risk, use sodium hydroxide to stabilize the copper cyanide solution to pH 9.
 

Thread Starter

Mazaag

Joined Oct 23, 2004
255
A very mild solution of sulphuric acid can be used along with the salt dissolved in it, but won't be necessary if the piece is already clean. .

is it the acid or the salt that isn't neccessary?

and wouldn't the acid dissolve the object i'm trying to plate? (its made out of stainless steel)
 

beenthere

Joined Apr 20, 2004
15,819
The idea of using a salt or acid in the solution is to make an electrolyte that will allow the material to be plated to be transported onto the anode (your stainless object). The copper ions have to be propelled by the potential field, but can move lots better if the water is conductive.

Unless the acid is very concentrated, the SS won't be attacked. Unless you're using FeCl.
 

bloguetronica

Joined Apr 27, 2007
1,372
is it the acid or the salt that isn't neccessary?

and wouldn't the acid dissolve the object i'm trying to plate? (its made out of stainless steel)
It is the acid that might not be necessary.

It depends on the grade of the stainless steel you use. But if you are unsure, you can use a low concentration of sodium hydroxide to take eventual grease out (stainless steel tolerates NaOH perfectly as it was water).

...Unless the acid is very concentrated, the SS won't be attacked. Unless you're using FeCl.
Indeed. but it is not only ferric cloride that attacks stainless steel. Other cloride based chemicals can do so, such as cloridric acid or sodium hypocloride (used in bleach).
 

thingmaker3

Joined May 16, 2005
5,084
If you want to plate SS (or other ferrous metal) with copper, I advise plating with nickel first, then copper. Results will be much more satisfactory.

SS is quite resistant to most acids. Sulfuric acid is an exception. Increasing the chromium content of steel actually increases susceptibility to sulfuric acid.
 
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