Get more life from abrasives
Pick the 'true grit'
Sometimes smoothing out a workpiece takes an abrasive rougher than Rooster Cogburn. If you try to hog away lots of material with a fine grit, you'll waste three things: your time, energy, and money. To remove lots of material quickly, turn to a coarse grit, such as 40 or 60. Save grits 150 or higher for finer sanding applications, such as sanding veneered plywood.
Slow things down
High disc speeds create loads of friction, and the resulting heat draws resin from the wood, rapidly clogging the abrasive. A combination of a gummed-up disc and high RPMs can cause black marks or burnishing on the wood -- where wood fibers compress until the surface becomes glossy and won't accept finish. Burn marks on your workpiece and black residue on your disc can also be signs of too-high speeds.
Apply a cleaning solution
If your abrasives have lost their bite, try cleaning them before sending them to the trash. Abrasive cleaning sticks work great for removing light pitch and sawdust buildup, as shown. But for cutting through heavily built-up pitch and burns, soak cloth-backed belts or discs in a commercial blade and bit cleaning solution (such as CMT's Formula 2050 or Trend's Tool & Bit Cleaner).
Heat, cold, and humidity can negatively impact the longevity of your abrasives. In the case of abrasive belts, environmental extremes can cause the belt splice to fail. Optimum storage conditions are between 35% and 50% relative humidity at 60-80° F.