Often when manufacturing acrylic parts, the goal is to have a part that is as clear as glass. Whether cast or ground to the necessary shape and size, the acrylic surface will obtain a matte or lightly etched finish – similar to a frosted finish.
This finish can be improved in a few different ways. Most commonly, the part is tumbled in a two-step process. The first step utilizes Plastic Media in a wet step to result in a uniform, matte finish. This step is generally needed if there are machining marks (like this part) or other deeper surface imperfections.
The second step which can sometimes be the only step needed involves dry tumbling with a Hardwood Media and the Hi-Glos Final Finishing Cream. This Cream has very fine abrasives that slowly polish the surface finish to an optically clear state. That clarity is seen in the part at the bottom of the picture. It is not uncommon to be so clear that you can read words through the part.
Both steps are best accomplished in a barrel tumbler due to the softer tumbling action and, especially with the Hardwood Media step, trapping the heat inside the barrel ‘activates’ the Cream.