Recipe for Limewash or Whitewash
Common recipe


2 c salt
6-8 c slaked lime
1 gallon water
Mix salt in water.
In part of the water mix the lime until it's a stiff paste.  Add water slowly.  Think gravy.  Making it thick initially keeps lumps from forming. Add the rest of the water.


Whitewash will look very thin on application.  Multiple coats 1-3 days apart work better than single thicker coats.  This allows the carbonation of the hydroxide to proceed.  If done in warm dry weather, the use of a binding agent that slows drying is necessary, or misting the coat.  

Recipe 2:  This one is low in salt by comparison to most.


12 c lime
2 c salt
4 oz elmer's glue.


Recipe 3:


12 cups lime
4 cups salt
2 gallons water


For additional durability: ONE of


2 tablespoons powdered alum OR
1/2 cup hide glue flakes OR
1/2 gallon skim milk


I suspect the glue gives the best durability increase.

From de Gruchy's Lime Works

A Lime Whitewash / Colorwash Recipe


10 lbs St. Astier Natural Hydraulic Lime 2 (NHL 2)
2 gallons of water
¼ cup of casein powder dissolved in hot water
½ cup of Borax (Won't allow mold &amp; helps repel insects along with the lime)
3 lb common table salt (Salt is proven to only be beneficial to lime whitewash to harden it. Don't use salt
with any Portland Cement based materials.)
¼ teaspoon laundry bluing for extra whitening or approximately ¾ lb of iron oxide pigment for a color
of choice. 
Add 1 oz Alum to help make the pigment become more colorfast


I've also seen 1-2% linseed oil added as a binder, up to 1/8 raw linseed oil for the liquid.  

A whiter colour and increased mildew resistance may be added by adding copper sulfate.  This does make the paint more poisonous in quantity. 



Traditional pre-made whitewash had fine chalk. (CaCO3) Since whitewash 'hardens' by Ca(OH)2 + CO2 => CaCO3 the addition of chalk reduces the amount of hardening needed. Too much chalk however and there's not enough binding to hold everything together.  Chalk doesn't need to be roasted in its making so it's a lot cheaper.

Wikipedia https://en.wikipedia.org/wiki/Whitewash

Good article:  http://pachamamatrust.org/f2/1_K/CBu_build/Se01_whitewash_KBu.htm

This latter mentions several other binders, and is oriented somewhat to conservation applications.