22 March, 2006

Shellac Basics

The great French builders usually wrapped handlebars in cotton tape coated with shellac. Today cork tape is the norm. While cork tape does provide better cushioning, it is fragile and needs to be replaced at least once a year. Shellaced tape lasts for years, or even decades. When it gets worn you can simply brush on a fresh coat. As for appearance, well look at the photos and judge for yourself. Even well worn shellaced tape has that special beauty or patina that's only evident in natural materials.

Yes, shellac is a natural material. It is the crusty secretion of the lac beetle (Coccus lacca) that lives in the forests of Assam and Thailand. It is a natural polymer that when dissolved in alcohol makes a varnish like coating sometimes called "French polish". Though I've never eaten any, I understand it's edible, however, denatured alcohol is not. You could dissolve it instead in good natured (grain) alcohol.

Shellac may be bought pre-mixed at most hardware stores in clear and amber tint. But it is better to mix your own from dry flakes that come in clear, amber, and garnet shades. Shellac should be fresh. Old shellac may not dry, will not be as clear, and may not be as water resistant as fresh. It must also be free of contaminents such as water. It is better to mix a small quantity of flakes with denatured alcohol as needed, rather than rely on a pre-mixed can that might be old. And since pre-mixed shellac is often available locally only in quart cans, the average rider will never use up even half a can before it gets old.

Shellac will add its tint to cloth tape. I like to experiment to find the best color tape and shellac for a particular bike. By the way there are several brands of cotton handlebar tape: Velox, Cateye, Tressostar, Viva. All are suitable for shellacing.

This photo shows the three colors of cloth tape I'm considering for my new bike.

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Here they are with a coat of shellac.

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1 comment:

steve said...

Yellow Tressostar tape coated with about four coats of orange shellac produces a color very similar to the "honey brown" of a Brooks saddle, for those who like color coordinated bicycles.