Damar Varnish, RetouchHow to make your own varnish |
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Contents1. Introduction  IntroductionIn oil painting, Damar resin is used as a final picture varnish, a retouch varnish, and as an ingredient in numerous recipes for oil paint mediums and glazes. A product of Southeast Asia, damar resin is the sticky sap of varieties of damar pine. The sap is collected, distilled and separated into turpentine and the solid damar resin. It is then imported to us in the form of pale yellow chunks or crystals, usually with embedded bugs, and bits of dried leaves and bark. In this state, damar is quite inexpensive. Damar has other uses as well. For instance, damar is FDA approved for coating fruit and vegetable crates. Most damar sold is labeled as Batavia or Singapore. Although Batavia is the more expensive grade, #1 Singapore is better for artists' purposes. Making your own Damar varnish is not only easy, it's very cost effective. A pound of damar crystals yields approximately one quart of Damar Concentrate. There is no mystery to the process, no special equipment is required, and you need only two ingredients: damar crystals and pure gum spirits of turpentine. (Do NOT use odorless mineral spirits). Making Damar ConcentrateThe first step is to make a basic 1-to-1 mix, by volume, of damar and turpentine. Thinning the concentrated mix with additional turpentine makes a final picture varnish or a retouch varnish. A 1-to-1 mix is not only easy to remember, but makes it easy to prepare any quantity you like, in almost any suitable container. You can make a mere cup or an entire gallon by utilizing the same proportions. To Make 1 Quart Damar Concentrate: Simple Method: 1 1-quart container with a lid (recycled glass jars are good) 2 cups damar crystals2 cups pure gum spirits of turpentine (note : use only pure gum spirits of turpentine, NOT odorless mineral spirits) If necessary, break larger crystals into 1/2-inch pieces. Combine the damar crystals and turpentine in the jar. After a day or two, or when the damar crystals have thoroughly dissolved, carefully decant the Damar Concentrate into a clean container. You can use a wire strainer or cheesecloth to capture any debris. "Teabag" Method:For this method, you will need some twine or dental floss - a length of about twice the height of the container, a piece of muslin or cheesecloth, some plastic wrap and a few rubber bands. Loosely wrap the damar crystals in the muslin or cheesecloth, and tie it snugly with the twine or dental floss. Pour the turpentine into the 1-quart container. vPlace the bag of damar in the container, draping the other end of the twine outside the container. Move the bag up and down in a dunking motion, thereby throughly wetting the bag and damar crystals.If the container lid will not fit because of the string, cover the container top with a double thickness of plastic wrap, and secure it with rubber bands. Thin string or dental floss will minimize a wick effect. If you observe wicking (turpentine will drip from the end of the string), just put the string into the container, on top of the bag, and close it up again. A couple of times a day, stir the contents of the container. As the damar dissolves, the thicker syrup settles at the bottom, and the bag of crystals can stick to the bottom, so be sure to loosen the bag when you stir the contents. After a day or two, when you see that there are no more crystals in the bag, remove the bag and put the lid on the container. If any debris has settled to the bottom, you can carefully decant the Damar Concentrate into another container. Keeping the jar warm will help the crystals dissolve faster. You can place the jar on a warm windowsill, or put it in a pan of hot water. You now have a fairly thick honey-like concentrated varnish. Making Damar Picture VarnishFor a final picture varnish, thin Damar Concentrate with an equal amount of turpentine : 50-50. (equivalent to 1/2 of concentrate strength) Making Damar Retouch VarnishFor a retouch varnish, thin 1 part Damar Concentrate with 3 parts turpentine. - or 1 part Damar Picture Varnish with 1 part turpentine (both are equivalent to 1/4 of concentrate strength). NOTE: In humid climates, you may need to add a bit more turpentine for picture or retouch varnish. Using Damar Varnish In Painting MediumsRecipes for oil-painting mediums can vary considerably. The medium recipe here, however, is fairly universal and maintains principles of fat over lean. Damar Picture Varnish : 1 part Combine the ingredients. May be mixed with tube oils on the palette, or rubbed directly onto the canvas as a couch for glazes. Stand oil or sun-thickened oil may be substituted for the linseed oil. Safety TipsTurpentine is highly flammable, so use appropriate precautions. Make sure you have plenty of ventilation when making these varnishes. After removing the spent damar bag, put it in an empty milk carton, coffee can or similar throw-away container with no lid; place it outside in a shady area until the remaining turpentine has evaporated completely; THEN you can safely dispose of it. Visit R E Roberts' Website Tutorial is copyright of R E Roberts
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