Resharpen a Glazed Diamond Blade by Dressing It Against Another Blade

The Problem

A diamond blade that's cutting slower than it used to isn't necessarily dull or worn out. The diamond segments can get "glazed" — coated with a smooth layer of ground material, especially from cutting tile — which keeps fresh diamond grit from ever reaching what you're cutting. Buying a replacement blade skips right past a much cheaper fix.

The Technique

1. Get a dressing stone — an abrasive block made for exactly this — or, in a pinch, another old abrasive blade.
2. Run the glazed blade against the dressing stone (or the other blade) for about 10 seconds, the same way you'd run it through a normal cut.
3. The abrasive action grinds away the glazed surface layer and exposes fresh diamond underneath.
4. Test the blade on a scrap piece — it should bite and cut like new.