Mural Conservancy of Los Angeles

As a member of the board of the Mural Conservancy I have participated in many discussions about the maintenance and conservation of murals and the problems that can occur as a mural is exposed to the environment and society's demons over the years. Board member and art conservator Nathan Zakheim has been recommending for many years coating murals with Soluvar as a final coating. According to Zakheim, Soluvar protects artwork very well, is non-yellowing, and can be removed if necessary to make repairs or modifications to the painting underneath.

Soluvar is the Liquitex paint company's trade name for a solvent-based acrylic varnish. This varnish is used by museums, art conservators, etc., to protect valuable paintings and artwork and is used by many artists (not just muralists) as a final picture varnish.

I am currently in the middle of a very large mural project in Santa Monica which is being sponsored by the City of Santa Monica. The City initially was insisting upon some sort of anti-graffiti coating for the mural, even though almost 98% of the mural is totally inaccessible to anyone except mountain climbers and human flies, as it is high up on a large, blank wall. I was not so concerned about graffiti, but was concerned about the effects of weathering. Therefore I decided to coat the mural with Soluvar, giving it some anti-graffiti protection and excellent protection from the weather.

I became convinced of this recently when, going through my files, I came upon a sketch for a small (4 x 8') outdoor mural I had done years ago for a store here in Santa Monica. It is the only mural I have ever coated with Soluvar. I go by the store occasionally and see that the mural still looks good, and I have stopped a few times and seen that it is still in excellent condition: the colors are bright and vivid, it has not peeled, and the surface is still shiny. The sketch for this mural that I found in my file was dated 1980! I couldn't believe it. 17 years!

This convinced me that I wanted to coat this current mural with Soluvar, as it is certainly the biggest and hopefully the best piece I have ever done. The main problem with this, however, is cost: Soluvar can easily cost upwards of $100 a gallon. A small 8-ounce jar costs almost $9.00 at a discount art supply. This current project would probably require 15 to 20 gallons to cover the entire mural. There was no way I could afford that within the fixed budget for this project.

I did have an option, however. Zakheim had spoken several times about making his own "Soluvar" at a much lower cost, and had even helped the Mural Conservancy make our own "Soluvar" to coat some of the murals in our Mural Rescue Program.

I went to Zakheim to get as much information as possible about making this varnish, and can now report that I have successfully purchased raw materials, mixed the varnish, and applied it to one large section of the mural (the mural is being completed in sections).

I purchased enough materials to make 2 batches (approx. 5-6 gallons per batch), and the total cost is about $300, or $30 per gallon. Zakheim recommends applying the varnish very thin. It is strong and it doesn't take much to protect, he says.

Following is a recipe for making your own Soluvar-type varnish to use as a final picture varnish for murals.

INGREDIENTS:

• 2 gallons Xylene or Toluene solvent.
• 3 gallons V.M.&P. Naptha solvent.
• 3 lbs. Acryloid B-67 resin (powder).
• 2 qts. Acryloid F-10 resin (liquid).

Solvents are available at professional paint stores.

Acryloid resins can be ordered from businesses that supply materials to art conservators. Some of these are:

DIRECTIONS:

• In a metal 5-gallon bucket place 2 gallons (or less; less is preferable) of either XYLENE or TOLUENE (xylene is preferable; toluene is more volatile). Metal buckets are preferable to plastic because there is a slight danger of spontaneous combustion with these ingredients in a plastic bucket. Metal buckets can be difficult to find, but some industrial paints and other materials still come packaged in them. I found some outside a factory that makes wrought iron. The lacquer they use to paint the iron comes in metal buckets. I cleaned out the old paint and it worked fine.
• Using a 1/2 inch drill motor with 5-gallon mixing bit, VERY slowly mix in 3 lbs. of acryloid B-67 resin crystals, a little bit at a time. If starting with less than 2 gallons of solvent and having difficulty dissolving all the crystals, more solvent can be added, up to 2 gallons total.
• Slowly mix in 2 qts. of acryloid F-10 resin liquid. (B-67 is a hard, brittle resin; F-10 soft and flexible. This combination makes the resin hard and durable, yet somewhat flexible).
• Mix for approximately 1-1/2 to 2 hours total, or until fully mixed.

This makes a CONCENTRATED Soluvar-type varnish (about 2 to 2-1/2 gallons). This concentrate can then be stored (in tightly sealed containers, of course) until you are ready to use it. Transfer to a plastic 5-gallon bucket with tight-fitting lid for storage.

Use this concentrate to prepare an appropriate amount of dilute varnish when you are ready to apply it. Makes approximately 5-6 gallons diluted.

When I diluted the varnish for application to the mural I placed the entire 2+ gallons in a clean 5-gallon bucket and diluted with V.M.&P. naptha to the top of the bucket. This made a wonderful, thin varnish which was applied to the mural with rollers with no problems. It created a thin, shiny, hard coating with no bubbles that dries in a few minutes, will keep the mural looking bright and clean, and add years to the life of the mural.

Approximately 4-1/2 gallons covered about 1200-1300 square feet of mural with one, thin coat rolled on. The varnish can be made thinner or thicker (by adding more or less naptha) for either spraying or applying with brushes (thinner for spraying, thicker for brushing).

One note of caution: this varnish seals the mural surface completely. If the wall has a problem with moisture soaking into the wall from behind, the varnish can trap the moisture in the paint layer which can then cause areas of the mural to be obscured by whitish discoloration.

by Art Mortimer.