Reconditioning old finishes

[Stéphane Collin]

Hello David.

If the old finish is shellac and still in good condition, but a bit dull,  I 
use a traditional product which is called here "popote" and which is tripoli 
powder in sour (acid ?) water (at 10°).
First make sure there is no more dust on the finish.
Put some popote on your left hand, and apply the product on a small surface 
of the finish.  Not too large a surface at a time.
With coton waste, or preferably with a rubbing pad formed of a piece of wool 
with a nice piece of finely woven coton fabric around it, rub the surface in 
large circles, with not too much pressure in the beginning (the tripoli is a 
fine abrasive).  After a short time, the acid water transforms in a very 
thin rubbing paste which does the work.  You can add progressively a bit 
more pressure.  Insist until the paste is gone and leaves a very clean well 
polished surface.  This takes about 3 minutes per surface unit.

I found this traditional method to leave the surface much less greasy than 
other modern finishing products.  In fact, not greasy at all, and remarkably 
stable.

After this, I can, or not following the situation, add one operation that 
makes the finish even more beautiful.  I use denatured alcohol (at 97°) with 
a little benzoene dissolved in it.  Make a rubbing pad out of wool and a 
piece of fine coton around it.  Put no more than a drop of benzoene alcohol 
on the wool.  Press the wool so to distribute the alcohol in the whole wool 
piece.  Put the coton fabric around the wool to form a pad in the shape of 
an egg.  The coton should preferably be absolutely white and smoothed by 
many washings, so to avoid that a too new coton would scratch the surface. 
It should not even feel wet when you put it against your lips, just nicely 
smelling the benzoene.  With a very light and quick movement, rub this pad 
on the finish making circles or large 8 figures, the meaning of this is to 
never stop the pad on the finish (it would burn it and leave a hole). 
Again, after the first contact which must be very light, you can 
progressively add some pressure, and make first smaller circles and 8 
figures, but finish with long strokes in the direction of the grain of the 
wood.  The benzoene adds some mysterious bluish shades and makes the surface 
look more supple to the eye, achieving the best looking finish I know.  This 
operation is tricky and needs a few catastrophees before you can handle it, 
but is worth the hassle.

Hope this helps.
Best regards.

Stéphane Collin.