Once at the plant I was working in, one of the electricians ordered a 4'x8' sheet of aluminum for a temporary power panel. The purchasing agent ordered a 4"x8" aheet and thats what we got. hehehe it turned out to be a pretty good sanding block when a peice of emery cloth was glued to it. I have also glued sanding belts to alum. unistrut for straight and vary rigid sanding blocks. This was used to sand my ribs all down evenly.