That's actually a really good question.  I don't do much in the way of resurfacing bowling balls but I use Abralon pads alot when refinishing golf clubs.  I would assume you could get away with using them longer refinishing clubs because it's more of a cosmetic issue rather than performance.  With that said I normally pitch them after a couple clubs but I use acetone and the paint and metal from the clubs makes more of a mess than a bowling ball.  It probably comes down to experience and trial and error.  My assumption is that everytime you use the pad the grit it can take a ball down to increases (meaning it becomes less effective).  For example if you have a 600 grit pad after the first ball the second might only be able to be taken down to 650.  You can tell by just feeling the pads that they become "softer" after every use.  In a perfect world I guess using both sides of the pad once would be the ideal situation but most of us aren't that rich nor that picky.

Edited on 1/21/2008 5:51 PM