An lump of copper that looks like an alien lifeform might fit the bill

The mixtures are available online, high acid ratio solutions (also known as "high throw") tend to be around 180g of sulfuric acid and 60g of copper sulfate added to 1L of water. High copper solutions tend to be around 210g of copper sulfate and 20-30g of acid per 1L. These numbers though are not "sweet spots" and actual ratios can vary greatly. The additives you add tend to dictate the concentrations since the additives are chemicals and therefore require a certain chemical environment to function properly.

If you are using no additives then the process can be very forgiving and you can just dump in acid and copper any way you want and still get plating if you just adjust your current accordingly.

As for how long it lasts. Once again the additives play the key role, they are the ones that deplete and change the makeup of your bath as time progresses. some additives will breakdown even without usage and so your plating bath will have a limited shelf-life.

In the case of no additives, technically the bath should last forever. This is because unlike most other metals in plating, copper plates with 100% coulombic efficiency. Every atom of copper that plates into solution from the anode is equally accounted for by an atom copper plating out of solution at the cathode. So even if you pump a million pounds of copper through the solution, it should technically remain the exact same composition as when you started (acid does not get affected by plating, it just helps the movement of ions and conductivity). However, real copper is not 100% pure. There will always be tiny bits of iron or other metals that plate into solution, but will not plate out. Over time these build up and contaminate your bath. But this a minor issue if you maintain clean practices and filter your bath often. I was able to run my baths continously for several months and contamination never became an issue. Although i still recrystalized my bath after that time just because i like the mental feeling of knowing i've got pure materials.




Around these forums you will find designs for constant current power supplies, i suggest you start there.

Personally I built my own switch-mode constant current power supply.

I do know that most casual platers get away with simply getting a giant unregulated power supply (transformer, diode bridge and capacitors) and then adjust the output with a variac. They watch the current through a shunt resistor. This method has the problem that the current isn't stable and might change as the shape of your object changes during plating.

Others use giant high-wattage resistors to control the current.

yeah the concept is similar. but the practicality is different. You're working with a solution that is highly acidic and corrosive and has copper sulfate which damages even stainless steel. most pumps will dissolve and leave crap into your solution if you use them. The high-quality pumps for corrosive fluids cost hundreds to thousands of dollars.

Most platers doing just plating (no electroforming) get away with just pouring their whole solution through a coffee filter every few days. This does run the problem that the coffee filter itself will breakdown and release contaminants into your bath.

Personally, I adapted a plastic aquarium pump to do my filtering continously.


Keep in mind: the primary source of particulates is the anode itself. As the copper anode dissolves it will drop off flakes of black copper that float around the solution. Therefore most platers place their anodes in a special porous bag that traps the particles but still lets ions flow through. A good bag will greatly reduce filtering issues.

depends on what type of bath you're using and what addtives you add. A high quality mix of additives with good bath agitation, continous filtration and precision current control can easily plate a quarter inch of mirror finish copper a week, maybe more (but i've never pushed it).

you could probably make yourself a nice copper plaque in a couple of weeks or so.

Something with no additives, no stirring and no filtering will take a long time. I was able to pull about half-milimeter a week with that setup. Pushing it further with more current only caused massive treeing that gave me a red "rock" that looked nothing like metal.


Remember, safety first, if you have little ones running around or moronic siblings keep this setup out of their reach. You will make a mess of the area you do it in and this unique combination of acids and metal salts will damage things you thought couldn't be damaged (i found that out the hard way).

While i don't normally plug particular companies, here is a company that sells complete plating kits (including those wonderful chemical additives) Plating Kits Electroplating Kits Aluminum Anodizing Kits Powder Coating Systems Metal Polishing And Buffing Supplies - Caswell Inc.

they even include the bucket!


Personally i made all of my own equipment and brewed up my own additives (i'm a chemist) so i never used plating kits and can't really comment on quality. However i've heard nothing but good things from my friends online. Although plating suppliers do tend to overcharge for additives since they are so important and few people understand them. I saw one company charging $100 for enough additives for 500 amp/hours of plating. Personally I can brew the exact same additive for $23 that gives 10 amp/YEARS of plating. So beware of additive price fixing if you decide to use them.


Have fun, and don't sniff the fumes

 

Did you go off a design you found here or somplace online or did you start from scratch?

The link to the plating kit you gave me says 0.07 - 0.2 amps per square inch of part surface area. I would think 5 amps or so would be big enough for me to start off with. Maybe all I would ever need?

So I take it the acid and copper sulfate don't harm most plastic? Or did you have to search for one that would stand up to it? I see Caswell has a filter kit for 22 dollars. Maybe this would be the easiest route. Caswell Inc. -Nickel/Copy Chrome™ Filter Kit


I tried looking for these on the Caswell site. Are they refered to as bandages?

Nope no pets or kids around to get into it. Wasn't even planning on doing it at home. I have a small tool repair shop and thought it would make a good spare time project. Does it create clouds of corrosive fumes like muratic acid does though? I don't want to rust everything.

Thanks again for your very informative replys. I don't feel so in the dark now on how this all works.

I think I will try to just start simple with no additives and go from there.
I will work on getting the basic supplys and a power supply and then I am sure I will be back with more questions.

__________________

 

I started from scratch, but its not as hard as it sounds. Lookup "constant current power supply" on the all-knowing Google and you can find loads of stuff. For your purposes, you can probably get away with simply using a computer PSU and putting some high-wattage resistors to get rid of the excess voltage.

I have a 200 amp power supply... 99% of the time, its set to 1.4 amps.... 5 amps sounds very reasonable for you. For the longest time i got away with using a 300 ma wall-wort.



acid copper plating baths don't harm most types of water-proof plastic. My plating "tanks" are converted plastic shelves and tupperware containers.


As for the filter, that particular filter is for removing organic contaminants rather than dust particles. Probably wouldn't be good for what you're trying to do.


More properly called "anode bags". Once again, consult the great and powerful Google.

A perfectly still copper plating tank will not spray anything. If you stir it using air sparging then droplets of the solution will fly out. very vigorous stirring will do that too. and inevitably, when you drop in stuff or pull out dripping stuff, solution will splash out. So Its best just make sure the area is expendable.

If in the future you plane to chrome or nickel plate, or almost any other kind of plating... remember that most plating processes do produce toxic fumes.

Copper though is relatively fume free, just the droplets are the worrisome part.

Still, it never hurts to have good ventilation.


Fun thing to do: spray a non-conductive object (like a leaf or even a dead beetle) with a very thin coating of conductive spray and plate metal onto it. For $0.30 of time effort and chemicals you can make yourself one of those $300 ornaments they sell at gift shops. Just remember its still a dead bug inside and will crush into mush just as easily