White wash paint has covered the surfaces of fences and walls for decades if not centuries to protect surfaces from the elements as well as to improve their look. The mixture was usually a combination of lime and water, which would coat the surface with a thin chalky layer of plaster. Homeowners would add ingredients that were cheap and easy to get, like white glue, flour, sugar, or milk to improve the coatings. You can make your own white wash for wood surfaces still today with common ingredients.
Mix 4.54 Kilogram of hydrated lime with 1 gallon of water in a 5-gallon bucket, adding a little more water if necessary to make a thick paste, using a stick or large spoon.
Mix another gallon of water with 1.36 Kilogram of salt and stir until dissolved, in another bucket.
Combine the two mixtures in the bucket of lime and stir well, adding more fresh water to thin if necessary.
Cover the bucket until ready to use. Paint the white wash over rough wood surfaces for the best adhesion. Store the white wash for several days in a cool dry place.
Add 1/2 pound of Portland cement to the mixture for plaster surfaces.