I was just polishing Ti a few hours ago. It's a bit like aluminum in that at high speeds the surface can "tear" and give a really nasty finish as if the metal were being pushed around in tiny clumps. This is the "orange peel" finish that folks are calling acceptable or even desirable these days. Basically, that's only a problem on large, flattish areas when using a tool of certain grits and high speed. As you move from coarse cutting into the beginings of a "finished: surface (say, 220 grit) the "tearing" starts. It can be avoided by lowering the speed, and is less of a problem the finer the grit gets from there. So try to go slow starting around 220 grit and you can speed up as you move to finer grits and polishing compounds. I wouldn't expect much trouble on a Dremel-sized job, anyhow.
That's been my experience.
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-Corduroy
(Why else would a bear want a pocket?)