What is the best way to polish small brass parts mechanically?

No no no! Not for clock gears!

Every bearing and mating surface, every gear tooth, every pinion - ruined beyong repair.

No choice but hand polishing. A "Dremel"-type handpiece with a tiny polishing mop will do the job if you're very careful to avoid the "works" (which, BTW, you should just leave alone).

All the above assumes you want the cleaned-up clock to actually work.

If not, just dump the lot in thiourea to soften it up, then a vibratory or ultrasonic cleaner.

-- Jeff R.

Thanks, I was hoping there was a way to do this. They all need much work to get running & would look alot better shiny as well.

MikeB

Use with I use this system for used rifle and handgun brass. It produces a mirror finish in a couple of hours. Heavy tarnish might take a bit longer, or maybe a pre-soak in Brasso.