Gesso Panel Part 3: Applying the GessoMarch 1, 2011
The batch of gesso I made last night has gelled, so I need to heat it before applying it to the board. I place my can of gesso into a small pot filled with hot water on the stovetop burner and gradually heat it up to around 130°F. My target is 8 layers, but I have added as many as 12, so I’m planning on at least 2 hours or so of work time. The process works best if the temperature in your studio is also nice and warm.
Slowly drag your gesso brush on the side of your container to discharge excess liquid and avoid adding air bubbles in the gesso. Bubbles are your enemy here. Brush the layer in one direction across the panel, and let it dry for a few minutes. Hold it up to a light to look for reflections from the water. Each layer should be applied in a perpendicular angle to the previous. You may need to carefully stir the gesso between applications if the solids settle to the bottom. When stirring I recommend doing so in a vertical motion, top to bottom, and don’t lift the brush out of the liquid while stirring.
After the final layer has dried to the touch, I’ll weigh the panel down to keep the board flat for a few hours as it completely dries. The last step is a light sanding with fine grit sandpaper to get it nice and smooth. You should notice that the surface turned out a bright white even though I used a lightly colored beige fabric underneath. Thin gesso covers well due to the amount of layers. I wound up with 10 layers on this one and used about ½ cup of gesso.
By the way, I wouldn’t recommend keeping the gesso longer than about 3 to 4 days, so use up as much as you can. Practice priming a few small pieces of sized wood panels (with or without fabric) to get the feel of the process. Before I start painting, I apply a coat of clear de-waxed shellac that cuts down the absorbency of the gesso.
About pinholes: the small ones can sometimes just be sanded out, but the larger ones will seem like moon craters. If you’re planning to use oil paint on the panel they may not eventually show up, but thinner paints like egg tempera won’t cover them up. There is a suggestion I can give you for patching them: beeswax paste. Take some bleached beeswax and warm it just enough to melt, and then add a small amount of turpentine to stir it into a paste. Take a paint knife and press a tiny amount of it in the pinhole, scraping it flat.