Rick,
As someone already implied, different manufacturers use particles of different hardnesses. So, different types of abrasives are more appropriate for sanding or re-syrfacing different balls. Those particles balls made by Columbia have in the past been of the softer variety. When they were sanded by regular wet/dry (silicon carbide) sandpaper, they were made into the same surface as the resin base in which they were imbedded; in practical terms this virtually made the particle ball into a resin ball and its reaction was altered to a large degree, if not entirely.
Over time, manufacturers seem to have changed the nature of their partcles so that many of them (Columbia, Brunswick and Storm) recommend that you can use anythign now to change the surface (sanding or complete resurfacing). Ebonite has a special procedure of sanding, polishing, then sanding again in order to resurrect their particle balls PLUS the use of Hook Again.
So, the safest method is always the one recommended by the manufacturer, and to follow their advice.
Like many procedures in bowling, there seems to be no one set method to their madness.
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"Just because you can do something does not mean you should do it."
"No good deed goes unpunished."