Over in Italy, [Robotfactory] has a new setup called CopperFace that they claim allows you to essentially electroplate 3D printed objects with a metal coating using copper, nickel, silver, or gold.
We’ve talked about electroplating on plastic before, but that technique required mixing graphite and acetone. The CopperFace kit uses a conductive graphite spray and claims it deposits about 1 micron of plating on the object every two minutes.
We couldn’t help but wonder if the graphite spray is just the normal stuff used for lubricant. While the CopperFace’s electroplating tech seems pretty standard (copper sulfate and copper/phosphorus electrodes), we also wondered if some of the simpler copper acetate process we’ve covered before might be workable.
Although the CopperFace’s web site mentions metals other than copper, it looks like they leave the details of setting up the plating to you. The unit itself is just a glass container, a magnetic stirrer, and a constant current power supply. The only part that might be harder to work out is the graphite spray. The company also mentions that you could coat the part with silver instead of graphite, but doesn’t offer details on how you would do that, nor does it appear anything other than graphite is included. The results (see photo to right) look good.
This doesn’t look as polished as the Orbit1 Kickstarter (although Kickstarter shows it as cancelled, their web site appears active as of June). However, the CopperFace looks highly producible (or reproducible) since it looks to be just off the shelf components. You can see more about the Orbit1 in the video below.
To coat an object with silver, what about silver bromide or silver chloride, as used in photography? Dip it in the solution, and expose it to light to free the silver atoms.
You could do a similar thing with tin and electrolysis
For the silver coating of plastic, we did that in high school, it was easy and fast. We used silver nitrate, some other reactive and a bit of heating (not very hot, about 70°C). I don’t remember exactly what other reactive we used, but I think it was pretty common.
We did that inside transparent plastic test tubes, in the inside, the plating did not look great, but with some polishing, it may had.
I’ll try to remember the reaction more precisely.
it was something like that: http://www.instructables.com/id/Make-Glass-Mirrors-With-Silver-Nitrate-Sugar-Am/
but I’m not sure we used ammonia.
Great, another totally misleading title.
It’s not even related, the title has to be for a completely different article.
(see warnings in this)
For an initial, no electrolytic plate, Tollens’ reagent is a way. It is a traditional tool for plating mirrors, and I how I did my first (and only) telescope mirror back in the day. Commercial preps are also available that are a bit less of a hazard. If one goes this route, the residue can include, and even age can produce, silver nitride, which is NOT something even experienced pyrotechs want to handle.
Another option, not including silver, is tin (II) chloride. Fewer issues and cheaper than silver, but, again, NO chemical or electroplate method is without risks, and NO plating method is clean. All produce residues that are toxic and environmentally bad. Proper postchemistry must be done, either by the user or by the appropriate waste handler, even at hobbiest quantities.
It’s a bucket
Hm… it says that it is deposition:
“6. Start the magnetic stirrer to begin the cycle of ‘electrodeposition’, by adjusting the supply current according to the surface of the object (about 1A – 1.5A for dm2).”
… rather than plating, which creates a much weaker and lower quality surface:
https://en.wikipedia.org/wiki/Copper_plating
“The plating seen in chemistry classes, often obtained with a coin and copper-sulphate bath, is in fact deposition, as opposed to plating. Subjecting the surface to any wear causes the deposit – which is not bonded – to spalt. Running such a bath for longer periods, one can readily observe the grainy texture left by deposition, whereas plating results in a smooth surface.”
How is this different from this, which has been around a while now:
“RePliForm was incorporated in 2000 in Baltimore, Maryland. Initially the electroformed tooling process was the main focus. With the help of customers seeking more robust models, Research and Development was conducted to formulate our RePliKote process in late 2001.”
“RePliKote – our coating process- enhances the capabilities of RP models allowing them to be used in demanding environments. This new technology creates an “armor coating” over your RP models.”
If you start with conductive filament (which is PLA or ABS mixed with carbon conductors) can you do good electroplating?
I wondered that too. Not an electroplating guru, so I don’t know.
“Conductive” filament really isn’t.
It’s more like “resistive filament” which is not conductive enough to act as a plating electrode
True, although I’m not sure graphite coating is all that conductive either.
Throw enough amps / volts at it and it will most likely become less relevant what the conductivity is as long as it actually is conductive to begin with. Unless of course it melts or destroys it first.
You can even “plate” (technically anodize) over electrically fairly non conductive aluminum oxide if you throw several hundred volts at it to continue the process.
https://en.wikipedia.org/wiki/Plasma_electrolytic_oxidation
“Throw enough amps / volts at it and it will most likely become less relevant what the conductivity is”
The idea here is that each charge carrier (IE the electron) that reacts with a metal cation on the substrate surface will produce a molecule of elemental metal on the surface of the substrate…..
As this process begins with a highly resistive substrate, the current flow will begin to rise due to the more conductive metal plating layer that is forming being more suited to carry higher current.
For some general rules of thumb with these processes, in order to wind up with a nice, well adhered, durable, dense, and shiny coating, you want to keep the plating bath at lower process voltages, lower temperatures, and lower concentration of cationic reagents……..
all things being equal, often times raising any of these parameters can decrease the quality of the coating.
Yea I’d imagine that raising the voltage to get past a certain point to get past the highly resistive filament you’d end up with an uneven coating. Since the metal would eventually make a lower resistance path. I’d guess you’d end up with something kind of ripple like or like a lightning bolt with a bit of branching?
“For some general rules of thumb with these processes, in order to wind up with a nice, well adhered, durable, dense, and shiny coating, you want to keep the plating bath at lower process voltages, lower temperatures, and lower concentration of cationic reagents……..”
If you are talking plating, I would generally agree. When you are doing plasma electrolytic oxidation, and instead of laying down a nice conductive material like copper or silver, you are laying down aluminum oxide, then you have to be blasting the surface with high voltage DC or in some cases AC power or the process literally stops due to resistance issues.
A lower voltage/amperage to start will deposit slower, but I’d expect it to get a more even coating. High current through a poorly conductive substrate would suffer voltage drop, leading to more deposition near the contact point.
Print in mercury or some other low melting point metal and have a really cold bed. :D
“We couldn’t help but wonder if the graphite spray is just the normal stuff used for lubricant.”
Could be. But I have a feeling it’s more likely that conductive graphite paint applied to the outside of CRTs. It’s been around for longer than I have, and has been used successfully to electroplate plastic objects. It’s called Aquadag.
By the can it looked more like GRAPHIT 33, often used to for the same application as Aquadag, but easier to find is spray cans. For their purpose, Id imagine anything with a high enough graphite content would work just fine, as long as the binding agent survives immersion.
This is not Metal 3D Printing…it is only the Electroplating (https://en.wikipedia.org/wiki/Electroplating). This kickstarter is untruth.