The media you are using probably has a softer or less abrasive
cutting agent. Because a disc finisher is very effective, you are
probably rounding the cutting agent. Or the carrier for the cutting
agent is too hard and does not wear down to expose more cutting
The Otec disc finisher that I used came with some appropriate
cutting media, both cones and pyramids. At the time, that media
worked well for many sessions. If you are using the suggested
media, I'd contact the company that makes your disc system and have
a discussion. It's hard to imagine a cutting agent that would become
rounded unless you are finishing some very unusual metal.
Judy Hoch, G.G.