Just to let everyone know, I'm polishing some rocks in the shop office. If it gets too noisy, feel free to move it AND post here where you moved it to. The rubber drum is MUCH quieter than the rock tumbler I had as a kid, so I don't foresee any irritance to other members...
I'll be checking on it today and plan to run it until at least Wednesday to check on the results. Generally, tumblers are run for about a month. I've used regular Silicon Dioxide sand which I don't know how well will work. If need be, I'll purchase Silicon Carbide sand which will be available to other members with the suggestion of donating $8 to the HF. 1lb. each of 60/90, 150/220, 500F grit SiC, and 0.5lb. of Alumminum Oxide polish, all together, is about $30 and will process approximately 4 batches or 12lbs. of rocks.
If anyone is interested in doing their own rock polishing, post here and I'll share my methods.
Credit goes to Steve who diligently added an "alignment wire" for the barrel because a clip was missing from his tumbler.
Also to note, the old army-green enclosed saw that was by the shop office on cleaning day and was moved to the members' rack is Steve's and is a lapidary saw for cutting rocks.