After covering the exterior with with our cob/cow dung plaster, the final step is two coats of lime wash also known as white wash. A neighbor had made lime putty from bagged, hydrated lime a year before. We mixed one part putty with two parts water using a paint mixer on a drill. When first applied, the lime wash is translucent. On cob or earthen plaster it looks muddy and uneven as you can see on the left side of the picture. However, in less than a day it becomes bright white as it turns into calcium carbonate.