Plaster, p5
"Daubing Out"
"Daubing out" is the process whereby any unwanted recesses or depressions in the wall plane are filled in. Although smoothing the wall to some degree may be desirable, removing all of the natural undulations common in a straw bale wall was not our objective.
To prepare to daub the low spots, wet the walls where the plaster will be applied until the plaster is saturated. 4 or 5 passes with the hose may be required. Remember, the scratch coat should be thoroughly wet, but not dripping. For the daubing plaster, the ratio of lime to sand should be the same as for the scratch coat - 1:2 (1 part lime to 2 parts coarse, sharp, well graded sand). The plaster should be applied up to a thickness no greater than 1/2 inch in one pass. If subsequent passes are required, wait at least 48 hours, then reapply. Scarify the wet plaster soon after applying it, as it has a tendency to firm up quickly.
A recess that has been daubed out. Note the discoloration in the scratch coat due to wetting.
Don't worry if the fresh plaster isn't perfectly feathered into the scratch coat, as the brown coat will cover both. Allow these built-up portions of the wall to dry prior to the application of the brown coat.