Has anyone heard of using sand as a cleaning/polishing component for tumblers?

Never heard of doing this. I believe sand is too abrasive and rather than polish brass, you would remove material. If you were looking to deburr steel parts sand might work.

Walnut or corn cobb laced with a brass cleaner.

Bad idea. You do not want to use anything that removes brass,just the crud.

In addition to the comments above, sand is heavy compared to corn cob or walnut hulls, I would think your tumbler would take a real beating.

A friend tried sand in his tumbler some years ago. The tumbled cases had the texture of those stick-ons you put on the floor of your shower to keep from slipping.
Sure cured any problem of too much bolt thrust!

Now I have heard it all, about time I'm 80 years old...

Not for polishing brass, for sure, but I use my tumbler (vibratory) with ceramic pellets for polishing and cleaning steel. Not brass.

I wonder if I wouldn't lose sleep at the thought of some sand grains sticking in tumbled cases and finally finding their way into my barrel

quote:

Originally posted by hivelosity:
Walnut or corn cobb laced with a brass cleaner.

Be careful with this. You do not want anything with ammonia in there, and most brass polishes/cleaners have ammonia.

Andre, how right you are. Sand [ SiO2 ] is extremely abrasive And when used you also get fine sand particles.
I solved an industrial problem when I heard parts were quickly wearing out carbide tooling .Sent out my technician to sample every step of production . The soft Al and zinc pieces had sand imbedded in them from a deburring tumbler .The carbide tooling was wearing very fast !
NO sand on guns please ! BTW sand + oil makes wonderful lapping compound !!

I tried it once and even when left in for a few days,did nothing.
I did use some junk brass to try it out.
Now i use crushed walnut/lizard bedding and/or corn cobb.

The bedding was cheaper and cleaned faster.