Electroplating ⚡🧪🔩

This week I took upon electroplating 3D prints. I started off with searching online on people who have done this before and I found a lot of information on there. These are some of the most helpful ones that I found:
Electroplating 1 📽️
Electroplating 2 📹
Electroplating 3 🧰
Electroplating 4 🧲
Electrolyte Recipe 🧪📜
Conductive Paint 🎨

Battery dissection

I started off by ripping apart batteries to extract the conductive material inside 🔋⚡. All safety precautions were taken to ensure any corrosive material doesn't come in contact with my skin 🧤⚠️. Also put a paper on the desk so that it doesn't stain my working area 🧻🧼. I started off with a needle-nose plier thinking that its was all I would need 🔧. But the first battery took around 25 minutes to take apart ⏱️. Aftermath of opening up one battery with the material collected 🧲 By the second battery I took out a lot more tools 🛠️. Learned a few tricks to implement, to accelerate the extraction process 🧠⚙️. For anyone trying to take apart batteries, first use pliers to krimp both the ends so that the metal casing becomes loose and exposes the zinc casing with the carbon rod exposed 🪛📏. With a sharp set of pliers make 2 cuts on the top of the zinc casing ✂️🔩. This creates a flap, hold onto this flap with a needle nose plier and start twisting it downwards like an oldschool tin can 🥫🛠️. This will expose the inside of the battery 🔍. Remove the paper inside, black powder will start crumbling everywhere at this point 🧻🖤. Make sure you have your collection bag nearby, because this powder will stain everything it lands on 👜⚠️.

5 batteries yielded around 46 grams of material altogether ⚖️. One mistake that I made was to throw away the zinc casing, this could be used for some other projects (I was informed by my mentor, I didn't know it was zinc at that time) 🧪. Also don't use Alkaline batteries ❌.

Conductive layer on 3D Prints 🖌️🧲🧤

After a nightshift of extracting conductive material from the batteries, Jesal Sir told me the carbon rods were only the thing I was after 🧠📌. The paste was not of importance. The carbon rods alone were also of no use as it is. What I needed was a fine powder suspended in a solvent, to apply on the 3D prints 💡🖤.

I took out all the battery internals and started separating the carbon rods from the paste 🧴🧽. This took about 15 mins ⏳.

Once these carbon rods were harvested and cleaned, I had to somehow make it a fine powder 🧂. With no expendable grinder in sight, it was time for a forearm workout 💪🗡️. I started scraping the carbon rods, and it was raining carbon (literally) 🌫️. I had to be very careful, not to breathe in this powder 😷. Even a strong exhale could blow the powder away 🌬️. Somewhere around 10 minutes of constant scraping I ditched the blade and brought out a metal file. This was way faster and now I had enough material to coat my 3D prints 📏⚫. It was time to mix this into a solvent and I used 90% IPA (Iso-propyl alcohol) so that it dries out faster 🧴💨. The original recipes suggested to use water 💧. I used a paint brush to make sure I could paint an even layer 🖌️. I coated 3 rings with different solute-solvent ratios. Each time adding more IPA. Painting against the grain was the most effective as the layer lines would hold the Conductive paint better 🎨🧲. My 3D prints were batman inspired rings that I had made in Fusion 360 🦇🖤.

Drying Overnight 🌙⏳

The conductive paint dried almost instantly but for safe measure I left them overnight to dry 🌙💤. They had started flaking off 🫠. I need to look for a better adhesive solvent for coating the surface 🧪🔍.

ElectrolElectrolyte 🧴⚗️🧫

The recipe that I followed calls for

150g CuSO4
30g Citric acid
20g Gelatine
10g Salt
800g Distilled water

This makes 1 litre of electrolyte.

This was my setup to make the electrolyte ⚙️🧪, I doubled the recipe and made 2 litres of electrolyte 🧂💧. I measured out the chemicals using an electronic weighing scale and kept them in waterproof bags until they had to be used ⚖️🛍️.

It's ideal to heat the water beforehand for easy mixing 🔥💧, I didn't do that which is why I had to mix for 15 minutes so that no solute was left 🌀⏳.

What else is conductive? 🧪🧲🔥

Then Jesal sir also had a few ideas of collecting carbon to make things conductive 🧠. This is him trying to collect soot from a candle from on a ceramic saucer 🕯️🍽️. The soot collected was mixed with acetone to make it easy to apply an even coat on small test prints 🎨💧.

Does it even work? 🧪🔌🧠

To test if my setup was working properly, I first used a small metal key (which is naturally conductive) 🗝️⚡. This was a test for all the factors that could affect the electroplating process. The voltage, electrolyte acidity as well as the connections made (more on this later) 📊🔋. So I attached a copper wire around the key 🧵🔗. Used the donor copper vessel as a container by first filling it up with electrolyte and connecting the cathode to vessel and the anode to the key 🔄🔌. Nearly 2–3 mins later I could see traces of copper deposited on the key, had I left it a little longer it would have been fully covered 🧲⏳.

First attempt 🧪🧤⛓️

Now it was time to electroplate my 3D printed ring 💍🧲, I used the same rig that I did for the key and submerged the ring covered with carbon from the battery into the blue liquid 🧴🟦. I saw effervescence almost immediately 💥. I knew something was happening. A few minutes in I went to check in on what was happening and noticed that the wire that I was using to suspend the ring in the electrolyte had somehow dissolved 😬. Why this happened? Because I had made the wrong connections 🔄❌. The anode was supposed to be connected to the donor (vessel) and the cathode to the receiver (ring) 🔌📌. With these learnings I knew it was time to use the big container 💪🛢️.

The copper wire was dissolved leaving behind a white powdery substance, which I speculate is some sort of sulphur salt from the copper sulphate used 🧪⚗️.

We are electroplating 🎉🧲⚡

I used a scrap piece of wood lying around and wrapped copper wire around it such that I could electroplate multiple things at the same time 🌲🔗. The tutorial that I was following suggested to use 1.5 Amps at the lowest voltage possible ⚡📉. That’s where I started off with when I used the small rig. For the big tub I adjusted the current till I saw effervescence on the node farthest from the power source. In my case it was 4.9 A 🔌💥. I had put 5 things in together all of different sizes but a good rule of thumb might be to use 0.75 A per centimetre cubed of the object you intend to electroplate 📐⚖️.

These are the items I put in to electroplate. After 30 mins of letting these prints sit in the electrified blue solution, I took them out to check how they were doing 🕒🔍. The carbon rod from the battery was completely covered in a thin layer of copper 🧲🟠. The rest of the PLA pieces had started to show signs of early copper deposits ✨. An hour in it was time for the second check ⏱️. I could see copper crystals forming on the carbon rod 💎🔬. The ring was 70% covered in copper—the rest, not so much 🧲⚠️.

Result 🏁📈🟠

This is what came out after 2 hours of electroplating ⏳⚡. The combination that worked the best was carbon collected from batteries mixed with IPA 🧪🖤. But as I mentioned earlier due to its poor adhesion, the coated copper layer had a very weak foundation and was very easy to rub off 😕🫣. The search for a better conductive paint continues 🔍🎨.

Now coming to the patchy coating 📉. My speculation is that because of the low adhesion and non-uniformly distributed carbon particles, my DIY carbon paint made discontinuous points on the surface of the prints 🧩🔬. So any part not directly connected to the copper wire did not get coated 🧲❌.

I would like to try other conductive inks available to see if I have any luck 🎯🖌️. The electrolyte made for this can be reused multiple times as long as it is filtered after every cycle ♻️🧪. This is one of the most profound things I have done at FabLab 🧠❤️. Now we race towards completing the final project 🏁🚀.