Regretfully, I'm using a small A-R1 Thumler, so my tumbling tinkering has been limited. I suspect that most folks just use the "standard" mixes in their Model B without much variation; however, I couldn't find any information on brass tumbling in the small capacity three pound barrel I had left over from the kid's rock tumbling days.
From what I read on the net, I think I'm running a higher ratio of brass to pins, approximately 1:1, than most folks and running shorter times. I seem to recall reading that the 15 pound capacity B boys are running 8 pounds water, 5 pounds pins and 2 or 3 pounds brass at 4 to 6 hours. I'm cleaning a pound every 90 minutes.
With my small diameter drum, I haven't seen any damaged brass, even with 3-4 hours of tumbling.
One of these days, I'll start getting my government check and may be able to buy the Model B.
A lack of planning on your part does not necessarily constitute an emergency on my part.
Last edited by serf 'rett; January 24, 2013 at 05:37 PM.