Tumblung info [Long)]

I don't get a good polish even when I go with a long fine grit and
then a cerium polish. What I would like to get is some first hand
and ideas from experience. Since I am looking at the
rolling barrels I would like this for comparison. 

First, I need to say this is what works for me-ask 10 people-get 10
different answers. No single method works for everyone

 How loud is it when running? 

You need to remember you are rolling rocks around in a barrel. It’s
going to be noisy. Rubber liners help with this some, and also help
protect the stones.

     How long does it take for a good rough grind? (Does it usually
take  two times with rough (36-90) grit to get the rounding
done)? 

I run my round barrel between 100-150 hours on my rough grind, my hex
barrel around 200. When I clean and dry the stones and at least 2/3 of
the stones look good I go to my next grind. No, I do not run my rough
mix twice. If there are stones that don’t look as good as the others,
I put them aside and put them in with my next run of new rough.

  How long does each other grit runs take to get the batch ready
for the next grit? 

I already covered the coarse run, then I run them in a 400 grit for
about another 100 hours, some more, some less, depending on the type
of rough. Then I take a few of the stones and polish them on the
buffing wheel. If they polish up, I go on. If they don’t they go back
in and I do this every 24 hours starting after three days. If you are
having trouble getting a polish on your stones, this may be where you
are having your problem. You could try going to a 600 and run for at
least 48 hours. I do this about half the time, depending on how well
the stones look at this point. Then the polish-run them until they
look the same-wet or dry. At least 48 hours. Then when I am happy with
the batch, I run them for 12 hours in a soap solution.

 What proportion of "fist size" rocks can be put in each load and
have the load all come out in good polish? 

That’s a judgment call. Experience will get you thru that one. Just
experiment but you can damage the smaller rough if you put to big of
rough in the barrel.

 Does the hex barrels work better than the round barrels? (From
your view.) 

Not better, but longer. And until you have the hang of it, you can
end up with more “flats” in the round. Those are stones that don’t
tumble, they just ride the inside of the barrel causing a flat side.

 How much 36-90 grit is used per load (50 pound load or what ever
your tumbler holds).  And for each grit size after this. 

I use (approx.) one pound coarse, one pound medium (400-600), and
half pound of polish for every 7 to 9 pounds of rough. If I had one
thing to say to really help you is you can never get the rough clean
enough between grits. You can screw up a batch of rough with just a
little contamination from the coarser grit. Clean them well. If I can
be of any more help, just ask. Larry Durnings Rings &
Things