How to Prime a Ground for Oil Painting

A dip box is useful in dealing with a whole batch of boards. If reasonably constructed it will not leak and the linseed oil is self sealing if your construction technique is not that hot (in that case use lots of silicon!) This one has an Aluminium lip ariound the top so as to catch any oil as you take the board out of the linseed. It is made to dip boards 47 by 62 cm and it takes about 5 litres to fill the dip box. Of course it will coat boards smaller than the above size, and you get the boards all cut and ready before putting the linseed oil in the dip box. A pair of long-nosed pliers are good for retrieving the board out from under the surface of the oil. Once the batch is coated, pour the remaining linseed back in the container, as it will skin if left exposed to air for too long.

Allow to dry one week for the boards to dry and then coat with lead white diluted in odourless turps to about the consistency of cream. Lead white is often only available in cans; Talens, (Flake White), Schmincke, (Cremnitz White) but the product in tubes, Blockx (Flake White) doesn’t go hard as in the cans and for that reason it is easier to use.

This example is of a quick sketch done at the sketching class I go to. You can see the crosshatch pattern on the board. it looks rather heavy, but you must remember there is only a whisper of paint on the board. Using the wipe-out qualities of lead priming allows me to establish the tonal values in one color  before introducing other colours. Do one thing at a time, it helps!

Brush with a wide soft brush so that the marks are as even as possible. Hold the board up to the light to make sure there are no huge furrows or ridges. Allow the board to dry horizontally for one week. Repeat the lead white coat but brushing the opposite way on the board so the brush marks go across the previous brush marks. (Once that has been achieved you can try next batch to make random brush marks in the second coat as long as they are not too noticeable.) Some artists repeat this process until three or four lead coats are achieved.

After drying horizontally for a week the boards are set aside to cure for as long as possible, usually 4-6 months. I have a space up near the roof where I can put my boards to mature, but even in that warm spot I’m never fooled into using the board too early. Unless the boards are allowed to cure thoroughly, the finished painting will crack and may even detach from the ground. Mark the back of the painting with a label so you know when it was primed, so you don’t use it too early. I have included an example of what happened to a board that was only left to mature for about three weeks after the second coat of lead primer. Cracking was only apparent about a month after the painting was finished.