I had to replace a head gasket and needed to do a better job of preparing surfaces that contact the gaskets. I could have taken the cylinder head to a shop where they could put it on their machine that essentially sands the surface but I came across a way to do the same in my garage. The block is a thick glass shelf (8" x 24") with two sheets of 80 grit sand paper attached with spray adhesive. I laid the block on the garage floor with a piece of old yoga mat in between to keep the glass from sliding and then moved the cylinder head back and forth on the block. It only took about one minute of sanding and the surface looked perfect. The sanding block can also be used on the deck of the cylinder bank but you have to make sure no debris gets into the bores and lifter valley.
