Trepanning circles the size required for my sandwich mirror experiment did not seem practical so I decided to try using my small diamond bladed tile saw.  A circle the size of the proposed mirror was marked out on the glass and straight cuts made to rough out the blank.  A wooden extension was added to the edge of the saw table and a lazy susan bearing loosely attached to it with one screw at the back so that the center of the bearing was on a line at right angles to the side of the saw blade where the glass would be in contact.  A wooden circle that fit loosely inside the bearing was siliconed to the center of the mirror circle, and a strip of wood the thickness of the bearing placed beside the blade to support the glass. The blank is spun on the bearing to knock off the high spots, then the bearing is nudged a little closer to the blade and spun again.  Repeat a few times and low and behold, a very nice circle! The usual precautions apply, outside if possible, lots of water, face mask, mitts (I didn't but the blood letting was surprisingly minimal}

  If the tile saw can cut circles, why not ellipses?  Here's how.  Make up a jig on the edge of a 2 X 4 by cutting out a V groove along it's edge and a  slot at 45°.   Cut a dowel  in two at 45º and hot glue the diagonal blank between the sections of the dowell.  Make up a spit that rests against the fence, {tilt the table to allow a bigger ellipse to be cut} and slide the skewer back and forth while rotating and out comes a diagonal.


Return to home page

Last revised - 19 Mar 09