system
Given the following post, respond as if you're commenting on Reddit:
human
How do you remove indium metal from a metal surface?

We got indium on a copper surface and want to remove the indium without damaging the copper surface.

Is ther anyway to do this with a solvent or anything from than mechanically peeling/scratching it off?
gpt
You can oxidize it off in a dilute acid solution. I'd use 0.1M Sulfuric acid, with include 0.1M Copper Sulfate. Volume of solution needs to be calculated based on the amount of In you need to remove. Don't let the Indium exceed 0.05M or so.

Use alegator clips to connect your In coated piece to a sheet or snarl of Cu wire that's been well cleaned and has at least twice the surface area of the one you're trying to save. The Indium should dissolve off leaving the Cu exposed below.

The Cu underneath might look a little dull but light polishing will restore the shine.