So in my spare moments I have been restoring this lovely old French cello. It’s had by the look of it a very full life with extensive work done on the neck and some sound post patches. It has a highly resonant top plate that unfortunately has split in several places and many of the edges and a corner are quite badly damaged.
The top plate itself has shrunk such that gluing it back together would like cause tension in other areas of the top plate and in places has been filled with a black glue that was quite hard to remove.
Leaving the top on the cello on initially, as it was to fragile to remove it, I set about rebuilding the splits with thin slivers of spruce inserted and stabilising the other five cracks. Then the top plate was stable enough to be removed and then worked on in my cello cradle. Here more than twenty cleats were installed across the various cleats. Cleats go cross grain in an offset pattern to spread the stress unevenly to other grain lines. These days I’m using parallelogram shaped cleats and finishing them in a slight pyramid feathering to the edge to remove mass – they are not as manificent as my teachers though. I then burnish them slightly with some pigments to blend it in with the old wood.
Next up are the edge repairs and corners repairs to the cello, unfortunately many of these go beyond the purfling line and the wood next to them is quite weathered as well, so I have gone for an edge doubling technique to provide better mechanical strength. The lower layer is hidden and thus can be slightly- or a lot cross grain for strength. Normally cross grain is somewhat avoided because of shrinkage cross grain with age will be different for the old and new timbers, but in this case was needed to hold the edge together. The top layer is matched for the grain of the top plate though. One the timber is rebuilt and shaped, new purfling can be installed once some channels are carved. Colouring new wood to old wood is a challenge, whilst I have the traditional pigments, building up the layers and how the light plays through it is a whole art in itself, the main thing is the repair doesn’t draw attention to itself.
Once all back together a new bridge was needed – it seems the top sits higher now that the structure has been restored…and the sound…sublime!!!