3M Radial Bristle Discs: Stack, Divide and Conquer
Radial bristle discs have made a big impact on the jewelry world. 3M took its inspiration for these tiny bristle discs from larger discs of similar design used in the automotive industry.
Sheets of special plastic impregnated with alumina oxide of various grits are made to fit a standard mandrel. 3M discs are color-coded by abrasive concentration, and can reach into crevices around prong settings, undercuts, and areas otherwise inaccessible.
To achieve maximum performance, Radial Bristle Discs MUST be operated at high speeds, meaning put the pedal to the metal. You can reach the suggested by pushing your flex-shaft pedal 3/4 of the way down. Lower speeds will give poor performance.
Important note on Radial Bristle Discs: Discs must be stacked in the same direction. If not, they will fly off and can cause minor damage to a surface. If you look downward at a flat disc, the bristles curve to the right. Alternatively, you may look at the disc itself and find the 3M logo. The logo should face downward.
You must stack these discs using a minimum of 3 to 6 discs. Do not use a single bristle disc as one disc offers too little stability and deteriorate under pressure. Like using a file or saw blade, let the abrasive do the work.This is a burnishing process, not an aggressive metal removal process. Heavier grit wheels are good for slowly removing metal, but they are not as aggressive as a file or coarse sandpaper.
Replace when your bristles are worn down to the hub. Discoloration on the bristles does change the effectiveness of the product.