I am cutting a mouse-hole in this thick slab of Tennessee Crab Orchard for a downspout to pass through. I’m excited because this is the first time I ever busted out the compass to bring to work.

I start by very carefully scribing a line with the grinder. This traces just inside the pencil line and will be my guide, to make sure I don’t cut away more than I need.

I run the big cut-off saw just to get my knockouts started. It’s too small an area to do much else with this saw.

On to the hammer and chisels, mixed with lots of kerfing with the grinder. The opening is going to be 4 1/2″ in diameter, which is the same dimensions as the blade on my grinder. You may be able to see places where I kerfed parallel to the top of the stone, as well as the more obvious up and down cuts. The blade binds quickly when I go parallel, but even shallow cuts help me remove material close to the inside of the opening.