Tuesday, January 23, 2007


Lime Plaster is based on Lime Putty. This pudding like product is made by Hydrating Quicklime by soaking it in water for a extended period of time. Now Lime Putties are only hydrated for several months, but in Vitruvius's time they were left it to aged for several years.

After searching Ottawa, I was unable to find Lime Putty, but found Factory Hydrated Lime in the powder form, sold in bulk (50lb). This powder is mixed with water to form Lime Putty. It is not as good a product as Traditional Lime Putty, but improves with age.

With great care I mixed this highly caustic brew!

By the time I am making my final model it will be close to a month old and hopefully in good condition.

Initial Tests have proved somewhat successful.

The Left Side includes a trawled on 1/4" layer of my 'Lime putty' mixed with sand (3:2)and second 1/8" layer mixed with less sand(3:1).
The first layer dried within one day and is very durable.
The second layer also dried quickly, but has some cracking and is not as strong.

The Right Side is a trawled on 1/4" layer of lime putty, sand and concrete (3:2:1)
The addition of concrete caused cracking and is not as hard as the first test.

Further additives to test for increased strength:
Skim Milk
Blood (from my next home cooked Hamburger meal)

Makes lime very runny.
Waiting to see final results...........
Result not good. Plaster applied with a trowel flaked and cracked, but the thicker layers left in mixing pot have formed a hard crust, so maybe it is best used for thicker base layers.

Lime on Lath wall,

Lime plaster cracked very badly and fell off lath test.
Perhaps because of new heating in Plaster lab, but it is too risky for the final built element so I will move to a gypsum product.

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