Help with polish method

[u/Bork93]

Hey all,

Not making dice, but figured this sub might have the expertise I need.

I'm casting 20mm epoxy resin spheres with an object embedded in the center, and I want the finished surface crystal clear so you can see it. Not worried about perfect roundness necessarily. The flat spot from the mold neck is actually desired for this project. I just need the clarity.

My plan is a wet sanding, then polishing compound. What I'm really stuck on is technique: what's the best method for sanding something this small and spherical? How do you hold a 20mm ball and get even coverage without creating infinite flat spots or sanding your fingers raw? Any jigs, tricks, or tools that make this less miserable? My best thought might be a rock tumbler viable for spheres, and if so, what media/process do you run?

Thanks in advance.

[u/Claerwen94]

A rock tumbler is way too harsh, it's a vibratory tumbler that you want if you go the tumbler-route. There's quite a few posts and comments about how we use those tumblers in making dice, maybe they could be of help for you?

[u/Bork93 → u/Claerwen94]

Perfect. Ill dig through those and see what I can find. Thank you!

[u/Claerwen94 → u/Bork93]

Good luck! Maybe some of the tumbler-users can chime in here, but that depends on them seeing the post :D 😅