Historic Whitewash Formula

  1. Salt: Common Sodium Chloride
  2. Alum: Powdered, Common Potash Aluminum
  3. Molasses: Unsulfured, Light Brown/Clear
  4. Water: Potable
  5. Quick Lime if you want to "slack" it, or Non Caustic, Hydrated Lime if you don't want to "slack" it
  6. Optional: Type I or Type II Portland Cement

A. 12 pounds salt, 6 ounces alum, and 1 quart molasses dissolved in 1.5 gallons water.

B. 50 pounds (1 sack) quick lime, mix with 5 gallons hot water. Allow to stand for 24 hours. Mix Parts "A" & "B" for a brushable consistency.

NOTES: Use this formula at your own risk. White, non-staining, Type I or Type II Portland Cement can be substituted for up to ten percent of the lime material to produce a more durable coating. Ordinary lime, or quick lime, is caustic. To get the lime you want for whitewash you have to "slack" the quick lime with hot water at least overnight. The result of slacking is hydrated lime, or Ca(OH2). But if the slacking is not complete or thorough it can burn your skin. If you are worried about incomplete slacking, buy hydrated lime instead of quick lime. Regular garden lime, which is really ground limestone, is of no use.

Crisp Point Light Historical Society Webmaster: Cameron Lovett
Last Modified July 24, 2004