Mirror Finishing

Edge And Surface Finishing

The extent of finishing needed to produce a smooth, transparent edge is based upon the quality of the cutting tool used to machine the edge.  A properly designed cutting tool with a sharp cutter will reduce the amount of finishing needed.  Finishing is also reduced when a spray coolant is used along with the cutting tool to reduce excess heat build-up.

Polishing: A polished edge is the best possible finished edge, but requires the most preparation. Prior sanding is necessary if the edge is shaped from a saw-cut, sanding is not necessary when there is a well milled edge.  A jointer, shaper, or hand-scraped edge can be used in place of sanding.  A stationary polishing head produces the best polished surface.  Bleached muslin wheels with a diameter of 8" to 14" with bias strips is recommended.  This gives the buffing wheel a pleated appearance, and runs cooler than a stitched buffing wheel design and will also do a fast job.

Polishing Compounds: The finished quality of the polished edge is determined by the polishing compound used.  To produce a high luster finish, the use of a fast cutting compound fist will remove all sanding marks, followed by a high luster compound for the final buffing.  To achieve a fairly good finish in one operation, a medium cutting compound would be best.

Polishing Surface: Prior sanding is not necessary when the scratches or machining marks are not too deep.  A surface polishing wheel should be from 6" to 12" in diameter, built to a width for 1 1/2" to 2".  For the initial polish, use a soft, bleached muslin wheel, followed by a soft flannel wheel for the finishing.

Depending on the depth of the scratches, use a medium-coarse polishing compound or a fine compound.

Be sure to keep the Plaskolite mirror in motion at all times during the polishing procedure.