Tumbling is the process of placing rocks (these may
be preformed beforehand or not) into a machine, that you will take
through different grades of course sanding material and eventually
polishing material. A tumbler may be a cylinder that rolls the rocks
over and over within it, or it may be what is known as a vibrating
tumbler, which just vibrates the rocks. When done in a vibrating
tumbler, you are more likely to end up with flat sided rocks.
Tumbling is a good way to use up those small pieces
and chips that are too small for cabbing or are already chipped
1. Select stones of a similar hardness or type. Stones should be
clean and may be of varying sizes.
2. The tumbler should be at least 75% full of stones, but no more
than 90% full.
3. Add enough water to just cover the rocks.
4. Add one laundry scoop of the 80 grit to the tumbler barrel and
5. Put the barrel on to the tumbler rollers and switch on. Check
to make sure that your barrel is not leaking, tighten barrel seals
if needed. Let the tumbler run for approx. 48 hours and then open
to release any pressure that may have built up. Check to see if
stones are grinding and if necessary add a little more grit. Return
barrel to rollers and let run continuously for a week before checking
again. If you are happy with the stones at this point proceed to
next step, if stones are not smoothed off enough return the barrel
to the rollers for a further week. This first step in the tumbling
process can take up to three weeks.
1. Wash all the stones and the barrel thoroughly to remove all of
the 80 grit, discard the used grit. If this is not done you will
not get a good finish on your stones.
2. Return the clean stones to the barrel and proceed as in step
one using the 400 grit. Tumble until you are satisfied with the
finish on your stones.
1. Wash and thoroughly clean stones and the barrel before proceeding
with this final stage.
2. Return the clean stones to the barrel and continue as before
using a polishing powder in place of the grit. Check after a week
to see if the stones are polishing and continue until you are satisfied
with the finish. Wash and clean the stones and the barrel thoroughly.
Enjoy your finished stones.
If your tumbler has two barrels it is recommended that you use
one for polishing only and one for the grinding process. After your
initial tumble you will be able to have some tumbling while others