THE GYPSUM [GESSO] GROUND FOR PREPARING WOOD PANELS
The Gypsum Gessoed wood panels are thought of as the most highly prized surfaces to paint on. I agree. They possess extaordinary luminosity and cause oil paint to stick to the surface like a wet fresco even in a light mist along the coast. This is my own personal formula that will help you to make your own.
Step 1: I begin with an solid oak board that is at least 80% kiln dried, 8 inches by 10 inches or larger by 1/4 inch thick. Score/scratch the wood surface with course sand paper to take off the smooth finish that the plainer left. I score the wood in a cross grain circular motion and scratch all sides of the board.
Step 2: Next I make a mixture of glue water, made of rabbit skin glue 70 grams to 1 Liter of water or a little stronger with 100 grams to 1 liter of water. In a double boiler, heat up the mixture until the powdered glue completely dissolves into the water, It should he hot to the touch but not brought to a boil. This will ruin the glue water and make it unsuitable for use. Rabbit glue comes in a powder form and you can get it through Daniel Smith Art Supplies.
Step 3: Then I allow the glue water to cool so that it is warm to the touch and apply one coat of glue water to all sides. Apply the glue by stippling the brush and apply thin. Since I usually prepare up to 25 panels each time I do this process, I place all of boards on two 1-inch by ¼ inch pine slats to keep the panel off the table to air dry. I paint all 25 boards on one side first plus the edges and allow to dry for about an hour. Then afer about an hour I flip them and do the other side. This seals the panel giving it a perfect moisture barrier. Then let them dry overnight.
Step 4: The next day I mix up the gesso using a measure of glue water, an equal measure of Zinc White, and an equal measure of Gypsum (or Terra Alba). You can get these powered pigments and chalks through Daniel Smith Art Supplies. Heat the mixture up in a double boiler until the powder is all dissolved into the hot glue water ( again do not bring to a boil or you will render the mixture useless).
Step 5: The first glue-gypsum white ground must be exceptionally thin, not wet, and must not be put on with a full brush, but stippled in such a way that it lies over the board like a veil. This is the most important step to avoid the paint curling off the board. Also never put a heat source to the panels to quicken the drying time. I paint about 25 panels at a time and by the time I finished with the last one I can flip the first one and keep going down the line. I usually begin by applying the gesso vertically.
Step 6: At about half an hour, after the first coat has dried on the surface, a second layer may be stippled on at right angles to the first in a horizontal manner.
Step 7: After allowing to dry at least a half hour for each surface, continue to apply up to 5 to 6 more coats of gesso in right vertical an d horizontal coats with a full brush now until the board is smooth, bright white and without veins of the wood showing through. These coats are essential in giving your boards a high degree of luminosity. They will also have a high degree of absorbency improving your adhesion of paint to the surface., considered by many to be the reasons why this board is the most highly prized surface of them all.
"Stormy Surf at Christmas Cove, Monhegan" an oil 8 x 10 in. by Michael E. Vermette
For information on a class Michael might be teaching about this process e-mail me at [email protected] or call (207)-827-7573.
