Thoughts From the Bench – Entry #4

June 5, 2018

In this edition of Thoughts From the Bench, I would like to explore with you the reason why I have three DEMCO Polisher/Grinders in the lab.

DEMCO Polisher/Grinder Model B-1

Each polisher/grinder is placed in different areas of the lab. In the model department, I use it to shape and bevel the model that was pulled from the impression, and ground down on the model trimmer. After pins are placed, and the base is poured, this polisher/grinder is used to refine the holes of the pins on the bottom of the base. A higher speed is used with a diamond separating disk to separate sections of the models. After sectioning, the individual dies begin the die-trimming process. I have found the DEMCO Polisher/Grinder is a wonderful tool, because no matter what part of the process I am currently involved with, I have the most control of the work piece. With the thumb and index finger of both hands, I am able to very carefully manipulate the die during the rough trim with an arbor band, followed by a secondary trim with a burr.

When using a hand-piece, one hand is holding the hand-piece; the die is held by only the thumb and possibly two fingers of the other hand. This is a not the firmest, or the most stable way of holding the work piece, and can result in an inaccurate trim. No longer do we ditch the dies in the process of trimming the margin. Especially, for those that are to be scanned.

The third phase of my die-trimming is done with a Bard-Parker scalpel with a #15 blade. During each one of these steps, I am wearing my 3.5 diopter loops.

-Kurt Culp, BFA, MA, CDT