Lately, much of my workshop time has been spent building left handed autoharps and most of that has involved designs and techniques that I have already posted about. So finally, here is something new.
Today I installed a laser cut rosette in my newest instrument’s 1/4″ thick spruce top. The soundhole was cut to match the outside diameter of the rosette. Under the hole I glued a “donut”, a thin circle of wood that created a little shelf for the rosette to rest on. I wanted the thinner rosette to sit more or less flush with the top so it was necessary to shim it above the donut. To do this, I applied little beads of “Bondic”, a unique sort of plastic adhesive that I’ve been playing with.
“Bondic” is much like superglue but instead of waiting for it to set up or misting it with a liquid accelerator, it hardens almost instantly with exposure to ultraviolet light. It can then be sanded, shaped, and even painted. Apparently it is nearly the same as the product dentists use to fill and build up teeth. So far, I have used it to repair chips in guitar nuts and piano keys, cracks in my old garden sprayer, and now to shim a rosette.
This was very “squeezy” and fun to do. First, I squeezed small beads of the adhesive onto the underside of the rosette where it will rest on the donut. Then I squeezed the little UV LED light to shine it for a few seconds on each bead. It hardened instantly so I could go around again to build each bead to the thickness I wanted. Lightly sanding the beads on a flat surface flatened them to a uniform thickness for a flush fit in the soundhole.