The metal tuning pin insert shims.

[Newton Hunt]

Metal tuning pin bushings do not work, I have tried them once.
Wood veneer works well if you use walnut or mahagony.  Maple, rosewood, beech
and other tryly hard woods do not squish enough to get a nice fit.

My initial reaction to using soap was no way, but it would be an interesting
experiment.  If I pulled a tuning pin to soap it, I would use a sandpaper shim,
with sand agains the wood or a wooden shim instead.  I would be concerned about
contaminating a useful block further down the road.

      Newton
      nhunt@rci.rutgers.edu