Slate tiles are made of several layers of material, or sediment that have fused and hardened together. These layers give slate a cleft, fragile surface with multiple ridges, humps and valleys. While these characteristics are what help give slate its appeal, it can leave a cut edge looking raw and unfinished. It is possible to grind down the edge of a slate tile with a bullnose wet saw blade. The key to finishing the edge is at the end, where you will need to grind down the top slightly, as it meets the edge to produce a uniform look.
Use a wrench to remove the bolt on the side of a tile wet saw, holding the blade in place. Remove the cutting blade and set it aside. Place a bullnose blade on the saw, and replace the bolt, tightening it down with a wrench.
Check to make sure there is water in the basin of the wet saw. Line up the slate tile with the bullnose blade. The slate should enter the inside curve of the blade when it is pushed in.
Turn on the wet saw and push the slate tile into the blade. The curved edge of the bullnose blade will remove the edge of the slate, and grind it down into a curve. You will need to push the slate into the blade several times for best effect; experiment first on a scrape piece of slate before moving on to the actual tile.
Fit the angle grinder with a coarse pad and turn it on its lowest setting. Grind the top edge of the slate tile, where it meets the curve. Remove any large clefts in the slate by grinding them down slightly, so the tile makes a nice transition into a finished edge.