Countertop grinders are in many ways a useful tool to have for any shop—from professional factories to the home garages of do-it-yourselfers. They can be used in a variety of ways, including grinding, polishing, smoothening, straightening, sharpening and other purposes. They are great for removing a lot of material aggressively, and with a finer grinding stone or wheel, they can also be used for delicate work such as polishing. Choosing the right grinder type is crucial so that you can achieve the results you have in mind.
Pneumatic or air powered grinders are pretty handy and can be easy to handle but will require an air source such as a shop compressor. They also cost less than their bulky electrical type counterparts. For big shops, this is a plus as they can use existing equipment with this type of grinder. But for smaller work spaces with no access to a compressor, an electric motor driven grinder is often the way to go. Electric grinders are bulkier and heavier, owing to the electric motor that is needed to drive them. They are ideal for a garage space or small work shed as they mount easily on a countertop. Most grinders like this have two wheels that offer a fine and coarse option to work with. They are often okay to use with wet sanding applications.
Wet grinders have the advantage of running water across the grinding surfaces which cools and preserves the grinding wheels or disks. They can be messy, however, as wet grinding produces slurry. They also need to be used in a space where handling water will not be a problem. Dry grinders, while producing dust particles during operation, are cleaner and can be done virtually anywhere. The excess friction and heat can be detrimental to their diamond grinding wheels but is manageable with the proper technique. A vacuum system can help with minimizing dust while operating a dry grinder.