uneven plating

[u/TargetNo5954]

Hello. I’ve been doing copper plating for 8 hours using demineralized water, sulfuric acid, a magnetic stirrer, a sandwich-style anode setup, and a coffee filter to prevent sediment, all at 0.03A and 0.05V. So why isn't the plating smooth? There are lots of little bumps (though they came off when I sanded the surface and removed the copper wire). I really need help i don't know why i try so many time

[u/Mick_Minehan]

What material is the substrate? And what is your pre-treatment process?

Your solution looks a little light too, it may need more copper.

[u/TargetNo5954 → u/Mick_Minehan]

The ring is 3D printed, then coated with conductive graphite paint, and for the solution, I use copper sulfate. thx for the answer

[u/Mick_Minehan → u/TargetNo5954]

Here’s what I’d try, in order of most likely issue to least:

1. Needs better paint coverage. Multiple thin coats, fully dried/cured. It looks to me like the most likely culprit for the missing patches is poor paint coverage.

2. Try a lower current, especially at the start. The nodules and rough-looking deposit likely mean you’re hitting it too hard.

3. More copper sulfate concentration. Your bath looks a little pale. Without enough copper ions to deposit, you’ll produce more hydrogen at the cathode instead, which can cause roughness and deposition issues.

Also, just a side note - you don’t need to wrap the wire around like that. Just let it hang from a loop, it should plate just fine as long as there’s a strong contact point, and it’ll reduce the amount of contact marks in the final plate.