Dry Shine III (3) Tumbling Media for Aluminum · Feb 26, 17:30
Tumbling aluminum can be a somewhat daunting task when first attempted. After machining your part, you want to keep it nice and shiny but also want to debur the part evenly.
We have tried a few types of tumbling media that claim to polish and debur but have found these (the ceramic and composite style triangles, cylinders, and the combination of those) to be really good at deburring but not very good at polishing. Typically (even when a burnishing fluid is used and the media strictly contains no abrasives) the finish gets dulled, after which point, getting that polish back is near impossible without human intervention.
While we do not claim to be experts in this area of finishing, we’d like to claim that there’s been sufficient empirical experimentation to warrant a few conclusions:
1. If you need to remove machine marks in a hurry, there’s no better way than to use a composite/ceramic tumbling media with cleaning/burnishing/polishing fluid. While the part will be nicely deburred, you’ll lose that shiny, post-machined shine.
2. If you’d like to maintain that post-machined shine, have little to debur and don’t expect your major machine marks to be removed, using a softer, natural tumbling media such as walnut shell (no, don’t go to the supermarket and buy bags of walnuts) WITH “red rouge” integrated into it is the way to go. We’ve tried going to Petco and local stores to buy walnut shell, but it didn’t have enough “oomph” to do much even after 24 hours of tumbling.
We tried media and 5 gallon tubs of cleaning and burnishing fluid purchased through McMaster and both tests returned results that led to conclusion #1. Finally, after some research, we tried to be frugal and go to Petco and purchase two 20# bags of walnut shell for just around $20. After an evening of tumbling in the Ultra-Vibe 45 from Thumler’s Tumblers, we found no appreciable difference in deburring. As for polishing, again, not much appreciable difference.
The following day, we received, from MSC Direct, a standard 30# bucket of Dry Shine III (3) Tumbling Media from Raytech (distributors?) which are a more even-consistencied walnut shell-based media with “red rouge”, which in essence is fine abrasive coated on the shell fragments. After 6 hours, we noticed the results that led us to conclude #2. Looks similar to post-machined polish with some deburring. Not bad.
On the left is the Dry Shine (coated) and on the right is the Petco walnut shell (uncoated). It’s not easy to see (and we’ll post better pictures later), but the Dry-Shine 3 is more evenly shaped and coated, while the “standard” walnut shell is more varied in consistency. More than likely, it’s the coating that makes all the difference.
What we really were expecting was a simpler 2-part process that has the deburring capabilities of the angle cut cylinder, cone, polyhedron, triangle, v-cut, cylinder shaped ceramic and ceramilite media, and the polishing capabilities to bring the shine back. Perhaps we’re missing something integral to the tumbling process… More on this later…
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