Paint Can Rock Tumbler: Thumler's Model A
A Thumler's Model A rock tumbler from the late 1950s. Note the two paint cans that are used as barrels!
One of the First Hobbyist Rock Tumblers
The first small-scale rock tumblers for hobbyist use were manufactured in the 1950s. Many of these early machines used metal paint cans as barrels. The metal barrels made the machines incredibly noisy. The paint can lids often came off from gas pressure or poor seating. And, a small dent in the barrel received a lot of abrasion from the moving materials inside, wearing it thin and resulting in a leak.
The photos at right are a Thumler's "Model A" double-barrel rock tumbler manufactured in the late 1950s and its wonderful box. The early Thumler's Tumblers used metal cans, but the noise and internal abrasion problems were addressed by inserting a rubber liner in the barrel. This was a rectangular piece of rubber that was perfectly sized to line the inner circumference of the barrel.
You Need a Barrel Silencer!
The noise from rocks tumbling in the metal barrels was more than the average person was willing to tolerate. So an invention known as the "barrel silencer" was invented.
It was a strip of rubber the same width as the barrel and its length was exactly the circumference of the barrel. This strip of rubber was placed in the barrel and served as a liner. With the liner in place the rocks would not bang on the inside of the barrel and create an enormous amount of noise. The barrel silencer also solved the problem of wear on the inside of the barrel and reduced the gas accumulation problem.
Some of the early rock tumblers that used paint cans were supplied with "barrel silencers". These were thin sheets of rubber that were used to line the inside of the can, protecting it from abrasion and cutting down on the noise. We have never used them but we believe that they would be an awful mess! The paint cans often "popped a lid" and that made a terrible spill.
The Rubber Barrel Innovation
Thumler's was one of the first tumbler manufacturers to introduce a rubber barrel to reduce the noise problem. In addition, their rubber barrels were faceted inside to improve the tumbling action. At that time there were dozens of tumbler manufacturers in the United States. Thumler's and Lortone were two of just a few companies to introduce rubber barrels, and that innovation gave them a tremendous advantage in the marketplace.
Great Products Persist in the Market Place
Almost all of the other tumbler manufacturers went out of business, and Lortone and Thumler's are two of just a few manufacturers of hobbyist tumblers that are still in business today. Their machines had great designs that were built to last, and the Thumler's machines sold today look almost identical to the late 1950s machine pictured at right - but they have much quieter barrels!
Original box for the Thumler's Model A rock tumbler shown at the top of this page.
The Early Days of Rock Tumbling
If you are interested in learning more about early rock tumbling see our article titled: The History of Rock Tumbling.