French polishing, also known as French varnishing or simply polishing, is a traditional method of applying a high-gloss finish to musical instruments, particularly violins. This technique involves applying multiple thin layers of shellac or spirit varnish and then buffing them to a mirror-like shine. The process is labor-intensive and requires both skill and patience, but the resulting finish can significantly enhance the appearance and, to some degree, the sound of the instrument.
Understanding the Basics
Before diving into the steps of French polishing, it’s crucial to understand the materials and tools involved:
Shellac or Spirit Varnish: These are the primary materials used in French polishing. Shellac is derived from the secretions of the lac beetle and is available in flakes or liquid form. Spirit varnish is a type of synthetic resin dissolved in alcohol.
Pads and Brushes: Soft cotton pads and brushes are used to apply the shellac or varnish evenly.
Polishing Compounds: These include abrasives like pumice or rottenstone, which are used to smooth the surface and create a high gloss.
Buffing Cloths: These are typically made of cotton or wool and are used to buff the surface to a shine.
Preparation
Cleaning the Instrument: Before starting the polishing process, the violin must be thoroughly cleaned to remove any dirt, grease, or old finish. Use a mild cleaner and soft cloth to avoid damaging the wood.
Sanding: Lightly sand the surface with fine-grit sandpaper to remove any imperfections and create a smooth surface for the polish to adhere to.
Sealing: Some violin makers prefer to seal the wood with a thin coat of primer or sealer before starting the polishing process. This helps to prevent the wood from absorbing too much shellac and ensures a more uniform finish.
Applying the Polish
Mixing the Shellac: If using flakes, dissolve them in alcohol until you have a thin, milky solution. Follow the manufacturer’s instructions for mixing spirit varnish.
Applying the First Coat: Use a soft cotton pad or brush to apply a thin, even coat of shellac or varnish to the violin. Work in small sections, overlapping slightly as you go to avoid missed spots.
Drying: Allow the coat to dry completely. This can take several hours or even overnight, depending on the humidity and temperature.
Leveling and Sanding: Once dry, inspect the surface for any unevenness or runs. Use a fine-grit sandpaper or scraping tool to level the surface and remove any imperfections.
Applying Additional Coats: Repeat the process of applying, drying, and leveling until you have built up a sufficient number of coats. Typically, several coats are required to achieve a high-gloss finish.
Buffing and Polishing
Initial Buffing: Once you have applied all the necessary coats and the surface is smooth and even, use a buffing cloth to begin polishing the violin. Start with a coarse cloth to remove any remaining imperfections.
Applying Polishing Compound: Apply a polishing compound like pumice or rottenstone to the cloth and work it into the surface in circular motions. The compound will help to smooth the surface and create a high gloss.
Final Polishing: Once the surface is smooth and shiny, switch to a finer buffing cloth and continue polishing until the desired level of gloss is achieved. You may need to apply additional coats of polish and repeat the buffing process to achieve a mirror-like finish.
Tips and Tricks
Work in a Well-Ventilated Area: Shellac and spirit varnish can produce strong odors and fumes. Work in a well-ventilated area to avoid inhaling these fumes.
Use a Dust Mask: When sanding or scraping, wear a dust mask to protect your lungs from inhaling fine particles.
Be Patient: French polishing is a slow process that requires patience and attention to detail. Don’t rush through the steps; take your time to ensure a high-quality finish.
Practice on Scrap Wood: Before starting on your violin, practice the technique on a piece of scrap wood to get a feel for the process and the materials involved.
The Impact on Sound
While French polishing primarily affects the appearance of the violin, it can also have a subtle impact on the sound. The hardness and density of the finish can affect the vibration of the wood, which in turn can influence the tone and responsiveness of the instrument. Thinner finishes tend to allow the wood to vibrate more freely, potentially resulting in a richer, more resonant sound. However, the impact of the finish on sound is relatively minor compared to other factors such as the quality of the wood, the construction of the instrument, and the strings used.
Conclusion
French polishing is a time-consuming and labor-intensive process, but the resulting finish can significantly enhance the appearance and, to some degree, the sound of a violin. By following the steps outlined in this guide and practicing patience and attention to detail, you can achieve a high-gloss finish that will make your violin look and sound its best. Remember to work in a well-ventilated area, wear a dust mask when sanding, and practice on scrap wood before starting on your instrument. With the right tools and techniques, French polishing can be a rewarding and satisfying process that brings out the beauty and potential of your violin.
