My house has a poured concrete foundation which sits 4' above grade. The previous owner did some patch work on many cracks, but he did't do a very good job. I would like to sand it down so the surface is more even.
The concrete will have to be ground down with a 'rubbing stone' or a heavy duty side grinder with a concrete grinding stone. Either way, keep the stone wet at all times and it will last 10 times as long as using it dry.