2020-01-01 Tungsten Ring Polishing
I had picked a tungsten (technically, tungsten carbide) wedding ring since I figured it would keep its shine forever. Little did I know about the effects of chlorine on tungsten. After a year or two of swimming lessons in a chlorine pool with my young child, it looked like this:
I took it off and left it sitting around gathering dust, then finally decided to do something about it. To polish something, you generally need something even harder in the polish, and there's few things harder than tungsten carbide. I bought diamond polishing lapping paste from eBay, 12 grades from 0.5 μm to 20 µm, for AUD $7.13, delivered. I have no idea about the quality, but the fact it worked counts for something.
Looking on YouTube, it seems most people place the ring in a vice, use a Dremel or similar tool to polish the exposed surface, then rotate the ring in the vice and repeat. This sounded tedious. So I 3d printed a mount which let me mount the ring in a bench drill press (could also use a lathe) and polish more lazily.
The results speak for themselves - this is only after a minutes or two of polishing:
I started with a coarser paste, 5µm, then 2µm, and finally 0.5µm, placing a small amount of paste on a cloth, and polishing the spinning ring. For a first attempt, with little time spent or research, I'm quite happy with the results.
It's still not back to "new", the ring mount means that the edges of the ring are more difficult to polish, and the inside is impossible. Thankfully, the inside is still as new, so I just need to spend a little more time polishing the edges.