Tuesday, 13 November 2012
We have used clay finish plaster on both the clay plaster on the straw walls and on the magnesium board. This clay is made and sold by Womersleys. When applied it tends to roll off the trowel, it can be applied thicker than the lime plasterers we tried and so on the magnesium board went over the beads better. It was better when mixed slightly drier on the magnesium board, but the magnesium board still tended to make the plaster dry very unevenly.
It took longer to get a good finish, and it was critical to catch it just right otherwise the surface tended to become dusty and not be bound properly. It did produce a nice finish which did not crack or shrink back. Clay plaster does not have a 'set' like lime, it is either wet or dry and it can forever be changed from one state to the other. This does make it more difficult to decorate, as when you work in the lime wash or paint it tends to absorb into the plaster and make it live again, rucking up the surface. One suggestion we are going to give a go is applying the limewash with a trowel - could be interesting!