This wonderful tool from Stewart MacDonal Guitar Shop Supply not only saves hours of work and reduces the potential for errors but it is fun to use and actually helps to protect vintage guitars which need to have binding replaced. This patient is a 1940’s Epiphone archtop
It is essentially a mini shaper-table of sorts. As you can see in the 1st photo there is a router mounted beneath it with its bit protruding up into the fixture to provide a cutting tool. The fixture itself is made to adjust with incredible accuracy; a dial indicator gives measurements in thousandths of inches. As the binding is drawn through the fixture, it is trimmed to a precise size, held in place by spring loaded fences and clamps. On many old guitar the outer body binding crumbles away leaving areas of exposed wood binding ledge around the guitar’s perimeter. Unlike a brand-new guitar whose binding can be scraped down such a technique on a vintage instrument can damage the precious original lacquer as the binding is shaved down level with the surface. It is painstaking work and one little slip can damage the vintage finish.
This fixture allows for accurate measurements to be made and the binding can be trimmed to the perfect size to fit the channel with no scraping needed! It simply glues in with a perfect fit. Once glued the binding can be tinted and finished by hand, preserving all the original finish on the guitar which of course is always the goal. In the last two photos you can see the untrimmed binding is about 27 1/1000 higher than the top surface of the guitar. After it is trimmed, it fits perfectly.
All the best, Scott