Traditional shellac may provide the ideal finish you are looking for when deciding whether or not to finish that newly acquired antique clock.
A modern polyurethane finish is not a substitute for traditional shellac. Polyurethane is tough and easy to work with but not reversible. Unfortunately, many people resort to using modern finishes on antique and vintage clocks because they are easily available, simple to apply, and cost-effective. However, in order to preserve the authenticity of a clock when the finish must be addressed, traditional methods are the best course of action.
Modern vintage clocks will often have a lacquer finish but for much older clocks shellac is the finish that would have been used at the time it was made. It is the best finish for most antique clocks. Shellac has been around for ages, began to be used extensively in the early 19th century, and remains a preferred wood finish to this day.
What is traditional shellac and how is it made?
What is it, exactly? Shellac is a resin secreted by the female lac bug on trees in the forests of India and Thailand. It is processed and sold as dry flakes and dissolved in alcohol to make liquid shellac, which is used as a wood finish.
Traditional shellac is preferred over canned shellac. Canned Shellac does not produce the same results and has a limited shelf life. Traditional shellac also has a limited shelf life but you need only prepare a little at a time. If you have no access to shellac flakes, check the expiry date on the liquid shellac can before using it.
Shellac is non-toxic with no fumes, and it’s safe for surfaces children and pets will be exposed to. It is easy to work with because it dries very quickly and can be applied by spraying or brushing. Intervals between coats can be a little as 15 minutes or less depending on the cut. Shellac also provides a hard finish and doesn’t yellow like varnish. If you must make repairs on shellac, you can simply apply a new topcoat of shellac over the old finish to get rid of scratches or blemishes. It comes in a variety of colors and can be stripped off wood surfaces with alcohol. Shellac does start to deteriorate after it sits in the alcohol mixture for a period of time.
Heat softens the shellac, so it is best if you avoid putting anything hot on or near the surface. If someone sets a glass down, the condensation may leave a white ring especially if the finish has a higher wax content. Having said that I don’t think many would put anything hot on a clock case although it is best to avoid heat sources, radiators, space heaters, etc.
Preparation and application
I use a 1 lb cut which is an 8 to 1 mixture, that is, 1 oz of flakes to 8 oz of denatured alcohol or commercially sold Shellac/Lacquer thinner. The instructions on the photo above describe the different cuts. The shellac dries very quickly and many coats can be applied in a relatively short period of time. I generally allow about an hour between coats, again depending on the cut.
Shellac comes in a number of shades but amber shellac, which I prefer, employs a warm glow to the finish. I will use either a broad artist’s brush or a French polish to apply the shellac. Each has its advantages. A ball fashioned out of terry cloth is the most effective method of applying shellac. French polishing consists of building up layers of shellac. Moisten the pad in shellac, wipe off the excess and apply in long strokes. A brush, on the other hand, is better when getting into tight spaces and wood cases with a lot of detail. Either way results in a glossy surface, with a deep colour.
400 grit sandpaper is used for rougher sections prior to the first application of shellac. A damp cloth is then used to clean off the residue from sanding. Allow drying. After the first and subsequent application of shellac, 0000 steel wool is all that is required to rub out any imperfections. Repeat the process two times and allow for drying time between coats.
Three coats are more than enough. More coats will produce a darker finish if that is your objective. If the finished result is too glossy and unnatural, dull it down with 0000 steel wool until you have the effect you want. However, there may be some situations where one coat is sufficient.
How long does it last?
Shellac in its liquid form has a limited shelf life of about 6 months much like canned shellac. In flake form, and stored properly in a cool dark place, shellac has a shelf life of about 3 to 5 years. I store leftover liquid shellac in a sealed glass container. I would advise against a metal container as the alcohol will react to the metal.
Let’s use my ogee clock as an example
This ogee clock is a fairly recent acquisition. The veneer is in remarkably good shape although the finish was dirty, dull, and lifeless. Many 150+-year-old clocks have missing veneer usually on four corners of the case and the door frame as a result of years of wear and tear but this clock is a rare exception. Veneer repairs must be completed before the finish coat is applied.
Once the movement is out of the case I lay the case on its back to begin the process of cleaning.
Murphy’s Soap is an excellent cleaner. Some may react to Murphy’s soap and a suitable alternative is Dawn or similar dish detergent. I use a light coloured cloth so that I can visualize how much dirt is being removed. Quite often the old shellac finish has worn off but if there is old shellac left there is a good chance it will be removed during the cleaning process. This is unavoidable particularly if the objective is deep cleaning.
Following the cleaning, 400 grit sandpaper is used for rougher sections. Clean off any residue with a damp cloth and wait for the finish to dry. Sandpaper is optional as I find it unnecessary in some situations.
Shellac is applied to the clock case while on its back using long broad strokes from an artist’s brush or a French polish pad. To avoid an overly glossy finish and maintain the light tone of the case one coat is all that is required as in the case of this ogee. Finally, 0000 steel wool is used to lightly “sand” out any imperfections.
To complete the effect Minwax Finishing Paste Wax is applied. It is a quality furniture paste wax that will protect the finish.