French polish

[John Delacour]

At 03:37 +0100 3/1/08, StŽphane Collin wrote:

>Hi John.
>
>I'd be interested in hearing your detailed process of French polishing.
>Everybody I asked seems to have his own method which can vary wildely from
>another, even if inherited from a branch of tradition.  I find it most
>interesting.

Thank you for your explanation of your methods.  I know that the 
French use pumice for filling the pores, and last year I experimented 
a little with this on small pieces.  I began my career as a 
pianomaker as a French polisher.  A friend of mine doing deliveries 
discovered two men working from garages who were polishing pianos and 
told me about them.  I went there and offered my services for nothing 
if he would teach me to polish pianos, and I was lucky because he 
polished in the traditional way and had always been a specialist 
piano polisher.

The English process differs considerably from the French.  I have 
reproduced my polishing "bible" here:

         <http://pianomaker.co.uk/technical/polishing/>

In most particulars I follow the procedure explained here, which is 
the way things were done at the beginning of the 20th century and 
presumably well back into the 19th.  This manual deals with high 
class polishing in general but at the end it deals specifically with 
the "glass finish", which we achieve on pianos.  I think you'll find 
it very interesting and well written.  The illustrations are terrific 
and you will also learn all the special technical terms, which are so 
important.

When I began I was taught to use filler -- in this case a patent oil 
filler.  when I became independent I experimented with various 
methods of filling but I now use no filler at all before fadding in. 
The pumice I use, when working on open-pored woods such as the Rio 
Rosewood of the mid 19th century, is used in the bodying-up rubbers, 
which my master referred to as "grinders" when used for pumice.  For 
these rubbers I use a covering of the linen that is used in the 
Italian alps for making cheese.  In Piedmontese it is called 
"reirola" and I don't know the italian name.

It is a long time since I did a chalk and vitriol finish, and I 
prefer to spirit off because it is less hard work.  Nevertheless, if 
you have the energy, the acid finish is faster.

 From reading your description of the way you do it I must say I get 
the impression that your procedures are very slow and that it would 
take a crazy amount of time to achieve a glass finish on a grand 
especially if you work on only a square foot at a time.  The bigger 
the piece, the more I like it, so that a grand top is fine.  I 
learned that in the old days they used two polishers when working on 
the rim of the big grands because otherwise the polish would 
evaporate too much before one man could get back to the beginning. 
This makes sense.

JD