• View of french polish on top of custom built Rantz mandolin.
  • French polish on top of mandolin custom built by Craig Rantz. Contact Craig to inquire about custom built instruments.

This is the first time I’ve attempted a French polish on an instrument. French polish is simply a term for shellac. The shellac is purchased in a dry, crystal form and Everclear grain alcohol (190 proof) is added to a set weight of the shellac as a catalyst to dissolve the crystals. Under normal conditions the rate of dissolution is about 24 hours.

The challenge with shellac is adding additional “layers” over existing coats without imprinting the previous coat with the irregularities of the application cloth (known as a “fad” or “rubber”). The lubricant used to solve this issue is mineral oil.

Still, even with mineral oil, one needs a quick hand and much practice to have good results. Typically, pumice stone is used in between coats to “polish” each layer – however, the layers are only .003” thick, so one has to be cautious not to take too much shellac off of the surface lest bare wood is exposed (then you must start all over again)!

These pictures show my first attempt … the luster is a bit matte, but still acceptable. I have about .006” of finish on the wood, which is about right.

Also, shellac must be applied from dark to light to get a “sunburst” finish. Don’t ask me how I figured that out!

Anyway, the finish shown in these pictures has yet to be buffed out with Johnson’s Paste Wax – this is applied for water resistance. The crazy thing with shellac, it is impervious to everything except water (or perspiration from the fretting hand), which is why violins and their family of instruments have the finish stripped from the backs of their necks.

I’ll take another run at this on another mandolin. It is a quick finish to apply and is easy to repair which is a real advantage compared to lacquer of polyurethane.

(Next: Fret Board Inlay)