I would like suggestions about plastic or steel shot media. Also the
liquid that should be used with each.
I’ve been using a small vibratory tumbler with about 7 pounds of assorted
shapes of steel shot for polishing (burnishing, really) sterling & fine
silver as well as gold items for about 10 years.
Along with the shot goes a pinch of burnishing soap (any low or no sudsing
soap (dishwasher detergent)) & about 1- 2 oz of household ammonia. Put in
the items to be burnished & turn the tumbler on. About 1/2 hour later your
items should be done. Remove the items & rinse in clear water. Replace the
cover tightly on the trumbler.
The shot shapes consist of balls, cones, rods & something that looks like
a flying saucer. The balls are about the size of BB’s. The other shapes
are relatively the same size or a little larger. The shot is available in
both carbon & stainless steel. Carbon steel is about $7.00/lb; stainless
about $12.00-15.00/ pound depending on where you get it. I’ve found
Thunderbird Supply in Gallup New Mexico to be the most economical source
for shot. The stainless is more expensive to buy, but is more maintenance
free in the long run.
What ever type of shot you use, it’ll all have to be cleaned periodically.
Cleaning is as simple as covering the shot with water, add some Draino or
lye (sodium hydroxide) & running the tumbler for an hour or until clean.
Pour the water & Draino/lye mixture off & rinse with clear water. Pour the
water off; add the burnishing soap (or substitute) & ammonia & its ready
to go. Keeping the lid on tight when not in use retards evaporation &
prevents rust if you use the caerbon steel shot.
Vibratory tumblers work faster than the barrel tumblers. Tumblers also
come in several sizes. The size selected really depends on the volume of
items you to tumbler & the speed required to maintain the volume.
There is a new magnetic tumbler on the market. It reportedly uses about 16
ga stainless steel pins about 1/4in (6mm) long immersed in a water &
burnishing soap solution. The items to be polished are put in the
container with the pins & solution & the machine is turned on. Magnets
under the container are spun around by a motor. This causes the pins in
the solution to spin in concert with the magnets. While spinning they
collide with the items to be polished giving them a shine. Several sizes
of these units are also available.
Prices I’ve seen for the magnetic tumlers start about $650.00 & go up.
Prices for the vibratory tumblers start at about $75.00 at most jeweler’s
supplies. The same item is available from gun shops, that carry reloaders
supplys, for less. Reloaders use them to polish their brass before
Items that are tumbled usually are work hardened to some degree by the
tumbling. Tumbling with steel shot will NOT remove scratches or other
surface blemishes. If scratched/blemished items are put in a tumbler,
shinny scratched/blemished items come out! Scratches/blemishes must be
removed using the traditional methods before tumbling.