In a job lot of kit purchased, I've aquired a 2 foot x 3 foot granite surface table in pretty abused condition. I'm tempted to get a local monumental mason to put it through his gravestone polisher, but how flat are the results? Looking at new granite graves they 'seem' optically flat from the reflected images, but are they? I'm only intending to use it as a marking out table, not the basis for a micron accurate co-ordinate measuring system!
AWEM