As the name implies, tile saw blades were designed to cut tile. However, the term "blade" is somewhat of a misnomer -- rather than cutting through tile, tile saw blades use grits of diamond to grind through the ceramic at high speeds. The diamond grits on the edge of the blade have a tendency to wear down and glaze over when you're cutting harder ceramic materials. Sharpening a tile saw blade requires making a slurry out of an abrasive material and the saw's coolant or water.
Reduce the coolant or water flow. Adjust the valve until the flow is half open.
Select an abrasive item to dress the tile saw's diamond blade. Any suitably abrasive material can be used to sharpen the diamond blade on a tile saw, including a dressing stick, a grinding stone, a breeze block, a soft clay brick or a chunk of concrete or asphalt.
Cut into the abrasive material four or five times, then turn off both the saw and the coolant flow. Wait for the blade to stop spinning.
Remove the machine's power source. Unplug the saw or switch it off at the appropriate circuit breaker.
Examine the entire edge of the tile saw blade for freed diamond grit. Use an eye loupe to look for little glistening black dots. Drag your thumbnail over the edge of the blade; if the blade is sharpened, the edge will feel rough, whereas a worn blade will feel dull in spots.
Repeat the process until the entire outer edge of the tile saw blade is dressed and sharpened.