Shopsmith Ceramic Velcro backed PSA Sanding Discs 120 grit

The following describes a series of six internal tests of these 12" ceramic abrasive discs, conducted by Jim McCann, Shopsmith's resident woodworking expert. All tests were conducted in-house, using a single 100-grit 12" ceramic disc on the Shopsmith Mark V - at approximately 1,600 RPM.

• Test #1: 2" x 4" x 2' Knotty White Pine
• Test #2: 1" x 3" x 2' Cherry
• Test #3: 1" x 3" x 2' Hard Maple
• Test #4: 2" x 4" x 2' Pressure Treated Yellow Pine
• Test #5: 1" x 3" x 2' Red Oak
• Test #6: 1" x 3" x 2' White Oak

In each of the tests above, we force-fed our workpieces into the rotating 100-grit disc as quickly as possible, until the wood was sanded down to just 4" long.

The tests each required from four to eight minutes to complete... around 40 minutes for the complete series, after which our Mark V headstock was quite warm.

As we completed each of the six tests, our disc was holding (but not clogged with) sanding dust. It's interesting to note that each time we switched from wood-to-wood, the sawdust from each previous wood was actually displaced by the sawdust from the new wood. This demonstrated clearly that that sawdust was, in no case, adhering tightly to the abrasive particles. When we finished the 6-test series, we simply used an abrasive cleaning stick to remove all signs of sawdust from the disk, and return it to like-new condition and color... almost as if it had never been used at all!

It's also important to note that at no time was there any evidence whatsoever of workpiece burning during or after completion of these tests. This is truly amazing, considering the speed at which we forced the stock into the rotating disc.