The wood treatment

It is always a bit strange to come to that point where none of the tools we used for the making are going to be used again for this instrument and a new set of tools and skills will come in.
When we were at school, the art of treating wood and varnishing and that of getting the sound out of the instrument was taught in the second year, when the wood working was the programme of the first year.
The number of techniques to treat and varnish an instrument almost equal the number of makers and restorers itself. It is a very personal skill... And the Secret of Stradivari is yet to be (re) discovered.

I accepted that UV light has a positive effect on my instruments.
Italian Masters use to hang their violins in their secadour, a construction at the top the house roof open to fresh air and day light but offering protection to direct sun light (that would have damaged the glue and distorted the wood)
Our UV cabinet with tanning tubes inside is a much less romantic but as efficient of the secadour.
Our instruments can spend as long as we can in it - the longer the better. I usually do at least 10 days.
In that special case, Douglas put the cello in the UV cabinet and waited for our son Loïc to be born.
He came a week late so by the time Douglas's paternity leave was ending, the cello had been 5 weeks in it. Wonderful.
The UV light tans the wood and gives a lovely buiscuity colour but also dries it out gently and makes the wood produce ozone that will react with other chemicals.
Then comes the Potassium Nitrite which reacts with the ozone created by the UV, darkening the wood a shade further. Next treatment is tea stain and ammonia fuming. The tea stain is only a very very strong tea with a drop of alcohol to kill mould and that applied on the wood gives more colour as the tannins contained in tea react with the ammonia. all of those treatments bring the wood to darken to a nice brown and the figure to come out without damaging the wood.