My first coat needs to be very wet, so the alcohol will melt a little into the old finish, so I'll saturate my pad and wipe on a coat with bold strokes.
I'll let that dry a few minutes and repeat the process two or three more times.
Now I have a lumpy, unsightly, rather sticky finish over the whole surface:
But, because it's so sticky, I feel that it will adhere and blend with the old finish.
Now I'll put on one or two drops of oil. (I've had good results with a variety of oils including synthetic lemon oil, linseed oil and walnut oil.)
I'll smear the tiny amount of oil over the surface with my fingers, and get ready to do the actual French polishing.
French polishing is exactly the same as spit-shining a shoe. Spit shining works because the water doesn't mix with the shoe wax, but allows more wax to be deposited from the rag as it passes over the freshly waxed leather surface.
In French polishing, the oil acts as a lubricant while pad spreads shellac repeatedly over the surface which is already sticky with fresh shellac. The real trick in French polishing is to learn to sense when you are depositing finish from your pad to the surface, and when you are dragging finish off the surface because your pad is too dry, or you're using too much pressure.
As with many handcraft techniques, it's a matter of practice and experience. French polishing takes a lot more practice that a lot of other techniques!
As I rub the pad lightly across the surface, I can see the rapidly evaporating trail behind:
The alcohol evaporates so quickly, that the surface haze of my wipe is gone in an instant:
At the end of this article, I have a series of photos that better illustrate the evaporating trail.
The point is that the trail of new finish loses so much of its solvent so quickly that I can wipe in a continuous circular motion over and over, each time depositing a micro layer of new sticky shellac. Every so often I "recharge" my pad with new shellac, and drop on a tiny bit more oil.
I want to use as little oil as possible because some of the oil becomes incorporated into the finish. Too much oil and the finish will tend to become sticky when warm, even years later.
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