The edges of slate are generally rugged and roughly square, hewn straight from the quarry and shipped by the manufacturer. In the case of backsplashes it becomes necessary to bullnose the outside edges of the slate tiles where they are exposed, allowing for a perfectly rounded edge that will enhance any kitchen backsplash and transform your kitchen into the most aesthetically pleasing room in the house.
Adjust the speed of the grinder to a low setting and apply gentle pressure against the edge of the slate. Use the roughest pad in the polishing kit in conjunction with the 4-inch hand-held grinder to begin smoothing the edge of the stone as you move the pad along the edge of the stone. The reason you begin with the roughest pad is due to the fact that the finer pads are reserved for polishing, not contouring. In addition, if you start off with the finer, softer pads the rough contours of the stone will shred the pads.
Avoid applying heavy pressure due to the softness of the stone--you may create a dip or too much of an angle along the edge, which can happen if you apply too much pressure. Create a slightly rounded edge by applying gentle pressure and pushing the grinder pad along the entire edge of the tile at roughly a 45-degree angle. Create a more rounded edge by rocking the pad of the grinder from side to side in a gentle arc as you work your way along the edge, varying from a 25- to 45-degree angle, depending on how much of a curve you are looking for. The more pressure you apply and the more passes you make, the more rounded and deeper the edge will be. Start with gentle pressure at first and make only one or two passes. Increase the number of passes if you think you want a more rounded edge.
Pay attention to the angle if you are polishing slate tile that is already installed, as too much could push the pad into the wall or surrounding cabinets, damaging those surfaces. If in doubt, simply put a piece of cardboard between the surface and your grinder for protection.
Use the softer pads in the kit if you want a polished sheen to the edge. The softer the surface of the pad, the greater the sheen you can create. If you want a rugged, natural look you should only use the roughest pads in the kit and simply smooth out the roughest sections of the edge. If you want a polished look, work your way down through the pads from rough to soft. It will take multiple passes with different pads to achieve a polished sheen.
All materials and tools can be purchased or rented from your local home improvement store, such as Home Depot or Lowe’s Home Improvement. If your exposed edges are a small enough area, you can use a simple handstone and sandpaper to achieve the same results as the polishing kit and grinder. The best course of action is to polish the edges of the slate tile prior to installation, but you can also polish tiles once they are in place.
Always be sure to wear safety glasses and a dust mask when working with a polishing kit.