Oil paint is suitable for exterior surfaces, and you can clean oil-painted surfaces regularly without damaging the paint. (You’ll need to use a solvent to clean brushes and equipment.) Oil paints can take a long time to dry — some will never completely harden — but this property gives the paint the advantage of remaining elastic as surfaces naturally swell and shrink.
Natural oil paints typically are made with linseed oil and a natural solvent, such as pure turpentine or citrus thinner. Choose raw linseed oil or linseed stand oil, which has been heated to a high temperature, making it more durable. (Avoid boiled linseed oil, which can contain a variety of ingredients that speed drying time, but may be hazardous to your health.)
When painting bare wood, the finished surface will look much better if you wet the wood with warm water and sand it before painting. Priming helps seal wood against moisture and creates a better bond with the finish. This is especially important if the paint is intended to cover the wood’s grain.
Basic Oil Primer
Combine equal parts linseed oil and natural solvent. Then apply a thin coat, in the direction of the grain, and wipe off any excess. When the first coat is dry (about 48 hours), apply a second coat.
Basic Oil Paint
Your surface will be ready for paint about 48 hours after the primer has dried. It is difficult to provide precise recipes for oil paints, because pigments absorb oil to varying degrees. Pour several tablespoons of linseed oil in a bowl and add pigment, a little at a time, until a doughy paste forms. Then you can add more oil just until the mixture flows. Next, add solvent until the paint reaches your desired consistency. Pour the finished mixture through a strainer to remove lumps.
Basic Oil Glaze
An oil glaze can serve many purposes. Sometimes you will want to put a glaze over flour or milk paints to increase water resistance. Oil glazes also make nice wood stains, with or without added color.
Yields approximately 2 cups.
- Dissolve 1 teaspoon each pigment and whiting (powdered chalk) in approximately 1/2 cup linseed oil.
- Stir in an additional 1/2 cup linseed oil.
- Add 2/3 cup natural solvent and 2 tablespoons whiting, whisking to remove lumps.
For more paint mixes see Make Safe, Natural Paint