Making your own varnish is neither complicated nor time consuming. All
you need is a few materials, a little storage space and, eventually, some empty glass bottles (screw on cap).
You can order a “kit” from Utrecht Art Supplies, 1 800 223 9132 or from www.utrecht.com. The “kit” is called, “Utrecht Ready-to-Make Damar Varnish” Item # 27101. You will get 10 1/2 ounces of Damar crystals in a cloth mesh bag and an empty quart can. You can follow the instructions which come with the “kit” but there is an easier and more economical way.
Empty the bag into the quart can. Save the bag for use later. Add 16 ounces (one pint) of pure gum turpentine. No substitute. Just pour the turpentine over the crystals and close the can tightly. Tap gently on the rim of the cover all the way around to securely seal the can.
Please note that you must use real turpentine. Paint thinner or any paint thinner substitute like “Turpenoid” will not work. Only real turpentine will dissolve the crystals. You can purchase real turpentine at many hardwares and at some paint stores. You will need 3 quarts of turpentine.
Every few hours for a couple of days shake and turn the can upside down then let it set. First the can will set upright, then turn it upside down and set it on its top. Continue to shake the can and turn it on its head etc....
It is a good idea to occasionally open the can (use gloves for that job) and stir the crystals with a stick, (the handle of an old brush comes in handy) as they tend to conglomerate at the bottom.
Open the can with a screwdriver. Actually, a quarter will slip under the lid very nicely and you can pry down gently to loosen the top. A few times around the lid and it will pop open. Do this for about 3 days, it will dissolve rather rapidly.
Put a small plastic funnel in a clean, dry, empty olive oil bottle. Place the mesh bag (cut open) in the funnel to act as a filter. Pour the varnish from the can into the funnel through the mesh bag. Put a cap on the bottle and place it in a safe place out of the sunlight. The varnish will turn somewhat brownish if left in the sun.
The varnish in the bottle is about equal in density to what is called “5 lb. cut” varnish that you buy in the store. The advantage is that your varnish is pure and cheap.
This varnish is good for several other purposes but we need thinner varnish. To make “retouch varnish” just add another pint of turpentine to the bottle. This will cut the “5 lb. cut” that we have just made to “2.5 lb. cut” which is the weight of retouch. We call this solution the “prepared varnish.”
There will be a mass of undissolved varnish in the can. Pour another pint of pure gum turpentine into the can and start the process all over. If there is still some sticky mass at the bottom of the can, you can pour in a half pint of turpentine and make a third solution. You should now have three and a half pints of 2.5 lb. retouch varnish in the bottle.
MAKING THE STAIN
You need another dry, clean bottle per color you prepare. Pour a good quantity of the varnish into the new bottle. Then you will select a cool or warm mixture to prepare. Ultramarine blue with a little Payne’s grey makes a good cool stain. You can add a touch of Carbazole violet for a beautiful violet stain. Alizarin crimson with a little Payne’s grey makes a good warm stain. Some artists like the fiery transparent red oxide as a warm stain. Put a small quantity of the paint into the bottle and mix it well with the varnish by shaking the bottle. If the stain is too light, add some more paint to the bottle, if it is too dark add some varnish. You are looking for a light value, it will dry lighter than the color you get when it is wet. I always keep small boards handy to test the color.
It might be best to get the stains a little light if this is your first try at stains. It is really easy to get them too dark and this will make
the whole painting too dark.
STAINING THE SURFACE
Pick a nice, sunny day that is not too cold (above 600 F.. ). You should not use varnish when it is very cold, damp or rainy. The moisture can cause the varnish to get cloudy, so pick a dry day.
The boards or canvases should have already been gessoed and dried for several days. Make sure you have at hand a good supply of these surfaces as you don’t want to do this every couple of days. It is just as easy to do 30 of these boards as it is to do three or four.
Set up a work area outdoors. Do not do this indoors unless you have a fabulous ventilation system of industrial proportions. Flatten some cardboard boxes and lay them out flat to protect the patio floor or the garden walkway from spills. You can get a plastic drop cloth from the hardware store to put under the cardboard. Stack up your boards or canvases in a convenient position, get a wide mouth container, (plastic will do), cheap OSH Chinese brushes, medium size ( it has to dip in the container) put your container full of varnish within reach but where it won’t get knocked over, dip your brush in and start the staining.
Use a large, disposable brush such as you can get at a hardware store. You want one of the white bristle brushes about 2 1/2 inches wide that cost about $2.00. Put on some vinyl gloves and brush out the stain on the boards or canvas. Tip the board up a little and start at the top. Lay a good brush load across the raised top edge. The stroke should be the full width of the brush. Let the stain flow down the board.
Recharge the brush with varnish and make a second stroke, just overlapping the first a little. This is very much like making a flat wash with watercolor. By now, you will have some of the varnish flowing down the board or canvas. Keep stroking the brush on the board, recharging when necessary to make a nice even stain.
Lay the board or canvas flat in a protected area. You want to protect the boards from dust, bugs, pets and small children. You can keep them outdoors under a protective roof, cabinet or in a shed while they dry. Don’t leave them out overnight if the dew can settle on them. Bring them in to the garage or balcony for the night and put them out the next day.
Let them dry a day or so, until they are completely dry to the touch. You can stack them up when they are dry and put them in a safe place for longer storage. If you have a carrying case it is ideal to dry your small boards, the ones that take more space.
It is a good idea to discretely put the date of the stain on the back of the board or on the stretcher bars of the canvas. You want the stain to dry a good 6 months before using. If you paint on the stain too soon, it will wipe off should you wash out something in the layout of the painting.
Keep the varnish out of the sunlight and it will last for years. Some artists make up several pints of stain at a time so they don’t have to do it very often.
If you do a lot of painting on small boards, you will want to make up enough to last several months. That way you only have to stain twice a year and you can let the boards dry long enough before you use them, that is at least six month for the varnish to be stable under a turpenoid based layout.
Have fun, you will love painting on a variety of surfaces with stained varnish.