Finishing raw castings

I’m curious as to how others finish raw (gold and platinum) What’s
your typical procedure/sequence? Are the “new” abrasives time-savers?
Does magnetic finishing satisfy the necessary burnishing of platinum?

Thanks,
D R

We use a otec maxi. Starat with very small steel pins then over
cermic cones them course walnuts then the final stage of fine
walnuts. We sent some raw castings over and they did all this free of
charge to show us what they could offer us. Great company to deal
with.