Here we go into the new year and what a day with the shooting in arizona, what a tragedy.
I would like to talk a bit about historical wall surfaces and help explain to those that need help and instruction-the proceedures to attain the unmistaken look of old surfaces from times gone by.
Old surfaces can be attained on modern constructed walls of dimension lumber, but for me the real look only comes when you are able to apply the surfaces to wooden lath or split lath applied over a timberframe structure covered with an interior smoothing surface of 1" square edged lumber
This smoothing surface is then smoothed further by applying vertical strips of lath that can be further straightened by using an 8 or 10 foot straight edge horizontally as one works along the wall surface to test and correct the relation of one vertical strip to another.
These vertical strips also allow an internal space for the plaster to squeeze through between the lath and form what is referred to as keys on the inside
It is these keys that need hair in the mixture to give the keys strength especially on ceiling surfaces to hold tight the weight of the plaster until the plaster cures and afterwards.
The true plaster wall surfaces contain 3 layers with the first layer containing hair or another suitable substitute such as hemp it is known as the smoothing coat and is scratched using a board with nails slightly protruding. The scratching will enable the next coat to bond with the first smoothing coat. A wood float is all that is used for smoothing the plastered surface
This coat is applied vertically from floor to the ceiling in stages of about eight feet or less and using the straight edge is levelled from edge to edge horizontally as well as vertically. A level is employed to make sure that the wall is plumb and true before moving on to the next stage. It is also scratched before moving on
One can work with smaller vertical strips if so desired but a truer wall will result from wider vertical strips being formed and used.
The historic mixture for this is 3 (shovels) of good sharp sand mixed with 1 (shovel) of slacked lime adding the hair or substitute to the mixture. The amount of hair or substitute will vary from one plasterer to another but the book says about one shovel of hair to a mixture of "20 shovels full". The book also refered to the use of "animal hair mostly from cattle but other types can be used". It also states that "ceiling mixtures should contain more for strength"