3rd of January 2019
The soundboard is made of spruce. Over the years the wood slightly expands and shrinks due to differences in temperature and humidity which can cause crackling. One thin crack all along the middle section had to be fixed (see picture below).
I first had to slightly open the crack in order to insert and glue a shim.
I could then apply some glue and insert the shim in the grove.
Once the glue set, I shaped the shim.
The old varnish was discoloured and started to come off. I first removed the old varnish, slighly sanded the soundboard and varnished it again. After a few layers of varnish and sanding between coats, here is a "100 years old brand new soundboard"!