I'm searching for a source of whitewash, or a recipe for making whitewash. Can you help? -- Barbara
By Kendall HolmesAt its simplest, whitewash is nothing more than a thin liquid plaster made from slaked lime and water.
But according to some of the books on my shelf here in the office (I've no first-hand experience with the stuff!) other materials were often added, including sugar, glue, alum and oyster shells. And for color, you could throw in yellow ochre, charcoal dust or brick dust.
Whitewash was popular in the 17th and 18th centuries in America, but by the mid 19th century, it was used mostly on fences and the exteriors of cottages, barns and other outbuildings.
As for specific mixing instructions, one of our bulletin board visitors at Old House Web with plenty of experience with the stuff offers the following tips. He notes that exact amounts are not critical -- but the methodology is.
Calcium Hydroxide is an agricultural product used to modify soil properties and should be available quite cheaply (about $6 Canadian for 20kg) in a farm or agricultural supply depot.
Solution 1: Soak 3 kg Hydrated Lime (Calcium Hydroxide) in 8 litres water overnight to make a thick, creamy paste. This allows the calcium into the water and is referered to as 'slaked lime,' which is the basis for house plaster.
Solution 2: Totally dissolve 2 kg table salt in 10 litres water. The salt adds 'body' so that the whitewash will wear well.
When ready to apply, drain excess water from Solution 1 and thoroughly mix enough of Solution 2 into all of Solution 1 to achieve the desired consistency. Thicker is better than thin as you cannot thicken the end product by adding more calcium.
Thin with water if required, but do not thicken by adding more calcium as the added calcium must soak (slake) properly before using.
1 kg powdered animal glue may be added to improve adhesion and wearability. May be tinted with a water-based media if desired.
