In the process called tumbling, the components are placed in a tumbling barrel. They are tossed around (tumbled) to achieve smooth and polished surfaces. During the process, the parts rub against not each other but what is called a tumbling media. This is necessary whether the barrel consists of open or closed work chambers.
The Role of Tumbling Media
Tumbling is a form of barrel finishing. It is often the least expensive mode of removing such things as rust or scales. The container that holds the media and the parts to be finished is called a barrel or tube. It may be open or closed. It may be divided or not.
The tumbling media is named after the action of the barrel. The media tumbles in the barrel with the added parts. The parts and media interact crating a rubbing action. At the same time, the tumbling media separates the parts from each other – preventing them from rubbing together. At the end of the cycle, the components have removed the rust, descaled and “finished” the parts.
Materials Used as Tumbling Media
The primary concern for selecting the tumbling media is based on part size, configuration, material, the size of the cut and equipment. The preference for and availability of either dry or wet barrel finishing will also have an impact on what media is selected or used. The actual media available ad utilized consist of a wide spectrum of materials. They include but are not limited to, the following:
* Carbon steel
* Ceramics – used with great frequency in the shape of a circle, star or triangle
* Corn cobs
* Dry ice
* Leather
* Nut shells
* Plastics two major categories are resin bonded and urea methanol
* River rocks
* Stainless steel
* Wood
Another factor affecting the choice of tumbling media is the desired result. The choice depends on the preferred result.
The Trouble with Tumbling Media
While tumbling is a desirable and relatively inexpensive way of finishing off the various components efficiently, it is extremely important to choose the right equipment as well as the proper tumbling media. This is not an exact science ad can prove tricky at a time.
It is essential to get both the equipment and media right. This will ensure that all the sections, angles, corners and edges of the part are reached. The part must be finished without sustaining any damage. No parts must adhere to the media nor should the media become stuck in various awkward and hidden holes in the component or the machinery. By finding the right tumbling media and ensuring it does the job correctly, you can be certain that the emerging component is ready and able to do its job.
