For centuries, there has been a secret used by cabinet makers and furniture makers to reduce the amount sanding needed in the final stages of of a project. This simple yet powerful technique has now been adapted to the specialized needs of today's wood-turners. With the development of shear scraping techniques the pleasures of cutting a fine surface rather than sanding it has become a much preferred practice.
Until now a myth has developed that implies that a burr raised by a rotating grinding wheel is a suitable edge for a shear scraper. If this pretext truly made a good edge, then why does it seem to work well with one sharpening but not work so well with the next? The answer is because a grinder burr is still a dull edge that needs to be refined. This is accomplished by honing off the inconsistent grinder burr and replacing it with a work hardened, burnished hook that can be two to three times more aggressive and will last five times longer than the best burr you can imagine.
There are dedicated turning tool burnishers on the market and all will work to roll an edge on a scraper. But the Derry burnisher does this task and a special one the others do not. It will also put an aggressive hook on the edge of the small tool bits we use on our hollow form boring bars. The small 3/16 and 1/4 inch cutters can seem very aggressive even a poor wire edge. But imagine having its edge last five times longer and cut with more control when you ever thought possible.
The differences in the two, side-by-side, burnishing pins. Simply point the tool tip directly at one of the pins, add pressure and swing the boring bar in a 90 degree arc until the the tip points directly at the other pin. The tool tip now has a work hardened hook that will work very much like a microscopic gouge. Once you have given over to the technique of burnishing you will never consider a wire edge grinder burr to be a sharp tool again.