Lewis Varnish System

My formal education is in chemistry and chemical engineering. So, naturally, I'm enchanted with the mystery of violin varnish. This is the methodology that I developed and used on my Norwegian Hardanger fiddle from 2020.

Wood Darkening

The purpose of this step is to allow the violin wood to darken via oxidation.

Option 1: Natural

After finishing and scraping the wood, leave the violin to sit in the window for several months, or in the UV cabinet for several weeks, until the wood has naturally darkened

Option 2: Nitrite

Apply a coat of dilute nitrite (NO2) to the violin. This is one product that is created when ozone interacts with the nitrogen in the air, so applying this to the violin simply speeds up the process that would happen naturally by letting the violin sit in a UV box (which creates ozone) or in the sun for a period of time. After applying the nitrite, allow to sit in the window or UV box for a few days. Nitrite is applied to the whole violin, including the neck. Following application, the wood fibers have likely been raised. For a corduroy look, you can leave this, but for a smooth finish, use a sharpened scraper and go over the violin. The nitrite usually penetrates about 1 mm, so scraping a little off the top won’t expose white wood.

Recipe for 4% nitrite:

• 100 mL distilled water

• 4 g NO2 (nitrite)

Put nitrite in water, allow to dissolve. Once dissolved, it’s ready to apply.

Sealing and Coloring

The purpose of this step is to seal the wood and provide a nice gold undertone color for the violin.

Apply what I call “scorched vernice bianca” to the violin with a brush, including the neck. Vernice bianca is advocated by Sacconni in his book “The ‘Secrets’ of Stradivari” and has been used successfully by many. I modified this recipe to scorch the sugar and honey component, which gives the nice golden undertone to the violin. I usually put 2 coats of this on.

Recipe for scorched vernice bianca:

• 25 g gum arabic

• ½ tbsp honey

• ¼ tbsp sugar

• 100 mL distilled water

• albumen from 1 egg white

Place the honey and sugar in a frying pan on heat. Stir constantly until is just starts to burn (the “scorched” part). At this point, remove immediately from heat and pour in a bit of distilled water. If the water is cold, the scorched sugars will likely solidify for a bit, but the residual heat will allow them to dissolve in the water. Bring the rest of the water to a warm temperature, but do not boil.

Slowly add the gum arabic. It’s a lot for how much water there is, so stir it in as you go. Strain the mixture through a fine cloth and let cool.

This makes enough vernice bianca for about 10 violins, but it’s likely you won’t need all of it at once. If the albumen is added, it will go bad within a month. Therefore, only add the albumen to a small amount of the mixture that you will use for the current violin, and do not add it to the entire mixture.

To get the egg white albumen, separate the egg whites and whip it into a meringue. Set the bowl on its side for about 20-30 minutes. A liquid will separate from the rest of the meringue. This is the albumen. Stir this in to the scorched vernice bianca set aside for this violin (again, do not stir into the whole mixture, otherwise it will all go bad!), and apply to the whole violin.

Ground

The purpose of this step is to provide any final sealing that the wood may need, and provide a ground for the varnish proper. At this point, don’t apply any more finish to the neck until the final neck sealer.

I use commercial Bullseye amber shellac and brush it on. I dilute the shellac with alcohol, about 2 or 3 parts alcohol to 1 part shellac. This just makes it easier for me to apply smoothly and evenly, although the downside is that it does require more coats. I usually do about 3 coats, but if some wood still looks thirsty, continue to apply only to specific spots after the first 2 or 3 coats.

I also tried a propolis-based ground on another violin, and while it was interesting, I didn’t see any particular benefit, and I feel like the recipe I used obscured the wood grain. However, it should be noted that some people really advocate for shellac, and others caution against it.

Varnish

My personal opinion is that the type of varnish used doesn’t particularly matter. This section will focus on my technique for applying. For the varnish recipe I used, see the Appendix, Michelman-based varnish recipe section.

I apply coats with a brush, but I’ve read about suggestions to only use fingers and hands. I haven’t tried that yet. On each coat, I follow this general procedure:

1. Use the tip of a knife to scrape any varnish buildup out of the corner between the ribs and plates. This will leave a little white scratch, which is accounted for at the very end.

2. After 3 coats of color (not before!), sand between each layer with 2400 grit Micro Mesh. Some makers recommend against Micro Mesh and suggest wet sanding, but I like Micro Mesh. The reason you don't want to sand between layers before adding several coats is that it could look patchy if it's sanded unevenly.

3. Apply varnish to scroll, then back plate, then ribs, then front (or whatever method works best for you). I like to apply varnish down the whole center of a plate, then start working outwards. The key is to just get lots of varnish on quickly. Also be sure to feather the transition between the varnish and no varnish section of the neck by rubbing the varnish with your finger.

4. After every other coat of varnish, I wipe the edges with a rag coated in turpentine. This keeps the edges from looking too heavy. Be sure to always check for any puddling.

Some other general process tips for the varnish coats:

• Since the violin already has a gold undertone from the scorched vernice bianca, I go straight to the reds and browns. With the varnish that I use, I control the color by using different ratios of colored powders, but the color can easily be controlled with commercial varnish as well, just using different available colors and dyes.

• Each successive coat should have slightly more oil than the previous. With commercial varnishes this isn’t as easy to carry out, but with my batch system, I mix up the first batch with about 2.5 mL of oil, then each coat I add about 0.1 mL of oil more (so 2nd coat has 2.6 mL oil, 5th coat has 3.0 mL, etc.)

• Be sure any turpentine you use isn’t oxidized. It should be clear. This was an issue with my first self-varnished violin, because I used oxidized turpentine, which resulted in tacky varnish that took several months to dry.

• If your varnish isn’t drying, try adding a siccative. Japan drier is available at hardware stores, and works well (it has cobalt driers).

• The next coat is ready to put on when you can press your finger into the varnish for a few seconds and there is no resulting fingerprint. I speed up drying also by using a UV drying cabinet (see UV Cabinet (about $150) section in the Appendix).

• If you want to "antique" the violin, study some old violins to determine where varnish tends to be thinner. After applying a full coat, wipe the varnish off of those parts. You can optionally add artificial wear to the violin by creating dents and scratches. I prefer to only do this by using items that a violin will typically see (for example, use the bow to create scratches, or rub my hand vigorously where the hand tends to rest on the violin). You can also add artists pigment to the scratches to imitate dirt buildup.

Final Touches

After the final coat, I let the violin dry a few extra days. It will usually take a few months to fully cure, but as long as it’s dry, you can set it up without damaging it.

After cleaning out the grooves between the ribs and plates with a knife one more time, I put some paint in to cover the white scratches. I do this with burnt umber pigment, and dilute it with turpentine (about 1:1). This allows for easier application of the pigment, as well as a thinner coat and faster drying. If desired, paint inside the pegbox and sound holes.

Finish the neck with neck stain, commercially available.

I do the final polish with Super Nikco polish from International Violin, but of course there are other options such as using pumice, rotten stone, or tripoli.

Appendix

Most varnish supplies I use can be bought from Wood Finishing Enterprises

UV Cabinet (about $150)

The cheapest way to do this was to get a metal trash can from Lowe’s (about $20), and put in 3 to 4 UV lights that are used in a reptile cage (about $30 each). I use 18” UVB lights. My dad helped me with wiring it up, but it was pretty straightforward. If you want more details on a cabinet, reach out to me!

The idea for this was found at https://stephenchurchill.ca/2016/08/31/a-uv-varnish-drying-cabinet/

Michelman-based varnish recipe

• This is a fairly complicated recipe, but can be made completely without heat. In addition to the raw materials, I would recommend a magnetic stir plate, scale, mortar and pestle, and pipettes.

• Raw materials are readily available from https://woodfinishingenterprises.com/product-category/products-for-violin-makers/

• The instructions for making the Michelman varnish are found here: https://www.fisle.com/bilder/hoyt/varnish.html. It is quite complicated and requires a lot of raw materials. If you want to make it, reach out to me! Otherwise, I recommend using commercial varnishes, since those will work well (if not better).