French Polishing
French polishing is one of the classic finishes for
wood. Although French polishing came to the fore in the
late 19th century, the underlying premise of using shellac
has been used for nearly 4000 years. In this article we
offer advice on one particular French polishing technique,
although there are certainly many variations.
Shellac is sold as a ready to use coating in most paint
and home improvement stores and is usually sold as either
a clear (blond) or amber (orange) colour. These ready to
use variations come pre-mixed with Denatured Alcohol. It
is also possible to purchase "pure" shellac
flakes that you can mix yourself. The advantage of this
latter approach is that it has a longer shelf life than
the premixed variations as once the alcohol and flakes are
mixed together the wax has life-span of about 12 months
(depending on the temperature).
Where
it comes from...
Shellac resins come from
the Coccus Lacca bug, indigenous to Thailand and
India, and are actually the insect's resinous
secretions. Ironically, for a finish that has such
as dubious start in life, Shellac has many
applications in today's world. The resin provides
a non-toxic, thermoplastic coating that is
approved by the food and drug industries as a
coating on fruits (where the resin prevents moulds
and spores) and drugs (where it acts as a slow
release enteric coating on many of today's
medicines. The Shellac has excellent adhesive
properties and can be polished to a high gloss or
rubbed out to a satin or flat sheen as desired.
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The "pure" Shellac flakes come in various
types of flake and, as standard contains a natural wax.
However, while the inclusion of this wax can make sanding
easier, in some cases the shellac does not adhere to the
wood surface too well. To address this issue, you can also
buy a de-waxed version of some Shellacs.
When mixing - or buying - shellac you should look for
the number of "cuts." Each pound of Shellac
flakes that is added to one gallon of Denatured Alcohol
equates to one pound cut. So, for example, if you were to
dissolve three pounds of flakes into one gallon of
Denatured Alcohol, the result would be a three-pound cut.
Normally Shellac is not used over a three pound cut, but
some manufacturers sell "ready to use" four or
five pound cuts. These should be reduced to a three pound
cut (or less) before application. Note: if you are
spraying the Shellac you should typically use a two pound
cut, but do so at your own discretion having consulted the
instructions proved with your spray equipment.
Applying the base coat
When first learning the art of French polishing, we
recommend that you use a ready for use Shellac. You will
also need to buy a bottle of Denatured Alcohol and a good
paintbrush, as it will be necessary to brush on three thin
coats of Shellac. Most ready to use Shellacs are
three-pound cuts and you should reduce this down to two
lots of 1 1/2 pound cut by doubling the amount of
Denatured Alcohol.
To begin the process, use the brush to apply the
Shellac to the wood ensuring that you apply a good even
coat to the entire surface. This first thin coat (the
"spit" coat) will dry very quickly under most
conditions. [Note: If it does not dry within an hour then
the Shellac is probably bad and should be replaced. In
this situation, remove the sticky Shellac surface by
applying more Denatured Alcohol.]
Once the first coat of Shellac is dry, apply a second
coat. Then, once this is dry apply the third coat. Once
you have added all three coats, leave the Shellac to dry
overnight. The next day, use a 600 wet and dry sandpaper
to smooth out the Shellac and then wipe off the sanding
dust with a tack cloth. You now have your base coat for
the French polishing.
Preparing the polishing pad
Mixing the French polish used within the pad comes down
to an individual's choice. When first learning we
recommend that you continue to use the 1 1/2-pound cut
that we used to created the base coat above. However, as
you become more proficient at this technique you may wish
to experiment with lesser and greater cuts.
Take a soft, lint free cloth - such as cheesecloth -
and fold it into a ball (called the "pad" or
"rubber." Now apply the Shellac to the pad so
that it is moist, but not dripping, with Shellac. Tap the
pad in the palm of your hand in order to disperse the
Shellac; the aim is to make sure that the entire front of
the pad is damp. We recommend that you consider wearing
surgical-type rubber gloves before beginning this process
as it can be quite messy.
French Polishing
The best way to comprehend the act of French polishing
is to imagine that the wood's surface (with the base coat
on it) is an airport landing field and that the pad is a
plane. What you are going to do is to practice allowing
the plane (the pad) to touch down on the field and then
immediately take off again, without stopping or even
slowing down (if you were to stop you would damage the
base coat). As you "land" slide the pad across
the wood's surface and then take off again, working from
left to right and then from right to left, overlapping
each stroke as you apply it. Slowly work up from the
bottom to the top and then start at the bottom again,
ensuring that you have enough Shellac on the pad so that
the strokes are uniform. You can add a little lemon oil or
cream polish to the pad to help make it slide easier
(although you should be very sparing with the oil).
Once you are satisfied with the wood's finish place the
pad in a jar and close the lid tightly. Allow the Shellac
to dry for at least a couple of hours and then take out
the pad again. Add Denatured Alcohol to the pad and tap it
in the palm of your hand to disperse the alcohol to the
front of the pad. Then lightly pad over the wood's surface
again. This process is known as "spiriting out"
and serves to remove the oil as well as further evening
out the Shellac finish. The result will be a far glossier,
smoother finish.
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