Official Luthiers Forum!

Michael's response to an earlier inquiry of mine has me wondering , can someone explain what happens when wood oxidizes? what are the changes that occure to make this phenominon happen. is it possible to retard or increase the happening of oxidation ? thanks jody

Oxygen reacts with some of the chemicals in the wood to form other chemicals. This is a bit similar to oxygen combining with iron to make rust. Some of these chemicals are darker than the original wood, so light wood then gets darker. If you watch Antiques Road Show, you will see occaisionally that the drawers are pulled from an old dresser to show that the light wood inside is not well oxidized (not darkened) even after hundreds of years, because the cabinet, although not completely air tight, inhibits the oxygen flow and also light. Extra energy can increase oxidation. If you add ozone (a high energy form of oxygen) you get faster oxidation. If you add bright, the light adds energy that speeds up oxidation. In dark woods, light can actually bleach the wood. The ultraviolet light is more active than visible light. I am not familar with practical ways to control this in guitars. I expect that some finishes really slow it down. I have heard of people deliberately exposing guitars to bright light for a few weeks prior to finishing, to darken the spruce, but that seems cumbersome to me.

Tony Stradivari used to tan his "in the white" fiddles on the roof of his shed before sloppin varnish on them.

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"After forty-nine years of violin building, I have decided that the search for a varnish is similar to the fox hunt. The fun is in the hunt."
Jack Batts Maker and Repairer of Fine Violins