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Let’s hear about the failures (Note: I used a modern junker movement in my
experiment, having first stripped off the lacquer.) Yup, there have been some. When I first got my tumbler, I used only
crushed walnut shells. That wasn’t enough. It took nearly three days to achieve a
finish, and then, the residue on the parts had to be cleaned off. Next I thought I’d add some common
liquid soap and water. Wrong! This became watery slurry of the crushed
shells and left the brass a very deep brown.
Only Scotchbrite would take off the brown finish. Then I spoke with Jim Moss about
the situation. He advised against
anything with water because of the battery reaction (leading to corrosion)
between brass and steel. Eliminating
the water was a “no brainer”. Next I tried walnut shells and
chalk. I remembered that Jim Moss
advised that he made a paste of chalk and Stoddard’s solution to hand polish
clock parts. This change in media produced
a rather pleasing effect, but the tumbling time was still in “days”, not
“hours”. The crud residue was minimal,
but there was still finish work to be done. Then I introduced stainless steel
Jeweler’s mix to the crushed walnut shells, and omitted the chalk. The stainless steel mix accelerated the
process a bit, but I still had to clean off the parts by hand. The crushed walnut shells would still leave
an undesirable crud on the parts. Finally I took a chunk of common
canning wax compound, grated a quarter teaspoon into the media of 20%
stainless steel Jeweler’s mix and 80% walnut shells. The pictures below in Step 3 show the
results after 8 hours. True, this isn’t the fastest way
to polish and clean, but it works all by itself overnight with beautiful
results. There are no “stretched”
holes from buffing, the edges of the movement remain sharp, and the parts are
clean. And a sad discovery, don’t put
distillates in a rubber lined tumbler drum.
The rubber gets soft and changes shape. I ruined the two tumbler drums in my Thumler A-R2 tumbler. Once I had liquid tight lids; now I have
leakers. They work fine for dry media,
however. (Note: since my last revision, the containers have
nearly returned to original shape and size.
I wouldn’t, however, suggest using spirits of any sort with these
rubber barrels.) I also have the new Model B
Thumler, which has a single 15-pound tumbling drum Large steel hexagon barrel
with removable rubber lining for long, efficient and quiet operation. Thumler and Grobet sell the tumbler; the
unit is marked “Grobet”, so I’ve no clue who makes it.
Sources of machines and tumbling
media are indicated below. And now for some feedback: Hi Ern, Noise can be a problem.
Being deaf helps. However, I
minimize the noise by putting the entire machine inside a large Rubbermaid
storage container (22 gallon size).
The tumbler unit rests upon a piece of carpet remnant, and the bin
rests upon a piece of carpet remnant.
In addition, the unit runs out on my back deck. Now, I generally run the tumbler at night
after I shut down the shop, so that’s also a possibility for you.
After the overnight soak and ultrasonic rinse, there is
virtually no dirt or oil present on the job.
However, the walnut shells will absorb any residue. The tumbling action will remove the patina,
fingerprints, rust and leave behind a very thin, protective layer of wax from
the grated buffing agent you introduce when charging the media mix.
Yes, although, there is so very little residue that comes
out. I always do it “just in
case”. Besides, I don’t want the oil
and wax residue to mix and cause a sludge. 4.
How fragile of a movement can you do (French)? Since my last writing, I’ve done several movements among which
were a Smith Westminster tall case movement, several American common time and
strike movements, a French crystal regulator, two anniversary clocks. I haven’t put gears and plates together
yet, though I might try. Since I
charge the tumbler drum to about 95% media mix, there is very little
opportunity for the parts to “free-fall”, moreover, when it’s running, it
sounds like a small avalanche. The
parts slide through the media rather than falling. Thus, it will take longer to tumble using
so much mix. I do not, however, run
the risk of possible fracture of count racks (the index tail) or very long
and hardened strike levers.
Yes, it’s very aromatic.
Think of gasoline. Also very
flammable. It does the job nicely. Caution around rubber and plastic. I’ve always removed hammer heads, for
example, when they have plastic tip inserts.
Leather is unaffected by the tumbling action.
It looks like anything can be tumbled. I don’t tumble clock parts except with the
request of the customer. Tumbling is
not a necessary repair step. It is
certainly not CONSERVATION. Leaving
the patina (oxide) on each piece means that oxidation is stopped. The piece is stable. If we buff off, tumble off, chemically
clean off the patina each time, eventually there will be no movement to
clean. Any removal of oxide is
actually thinning the plates and components, however miniscule. Next I plan to tumble a bezel in the tumbler, by itself. First it will be without glass, then I’ll
try one with glass.
Nope, rust, corrosion, fingerprints, blotches… they all
disappear in the ONE media mix. I
should note that stainless steel Jeweler’s Mix is rather expensive, on the
order of around $12 a pound, however, ordinary and cheaper steel mix can be
substituted if you’re not using a water based cleaner in your process. You’re welcome, Greg. 8.
Here’s a tip from Dean Sarnelle of
Once Upon A Time of Staunton, VA. Dean
introduced me to tumbling. Put the wheels on a wire through any holes that media might get
stuck in. It is also easy to pull out
of the tumbler with all the wheels at one time. I have used the same carbon steel for 17
years now. Dean Addendum: Since my last writing, I purchased a
Lortone two drum tumbler at a local tag sale.
Though I had to clean it up, oil the motor and rollers, it works like
a champ. It will be great for small
parts. Up to this point I hadn’t tried
plastic media. With this purchase
($6.00), I also got about 10 pounds of plastic pellets. So I dumped these pellets in with the
stainless steel Jeweler’s Mix, crushed walnut shells and buffing compound,
and I love the results. Most notably,
the noise level dropped. I think,
moreover, the plastic pellets acted positively as a sound dampener as well as
a good polishing media. Awesome. Commercial Sources: The
Rock Shed good source for tumblers and parts for tumblers. If you’re into rocks, he’s got the
stuff. Honest seller; he even refunded
a postal overcharge. Findingking.com (ß click link) is a first class supplier. His goods are offered on Ebay, which is
where I got a fantastic deal on the Thumler Model B large capacity machine. You can also order tumbling media, and a
multitude of shop supplies and equipment directly from his web site. His Ebay ID is findingking@fastq.com . Ebay – a great place to pick up
new tumblers Tumbling
Media (a reasonable substitute would be a few pounds of 4 penny finish
nails 1-1/4” long available by the pound --- cheap, as well as #4, #6 and #8
flat washers. They’re on Ebay, cheap) Hobby Warehouse http://www.hobby-warehouse.com/thtumobrotu.html
(current price $137.00 … a very good price) Grobet USA http://www.grobetusa.com/ (no online
catalogue) Kingsley North http://www.kingsleynorth.com/ Kramer Industries http://www.kramerindustriesonline.com/ 4 Facets http://www.4facets.com/index.html MSC Direct http://www1.mscdirect.com/eCommerce/NavigationServlet?ta=Y&N=12100017
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