Masons use a wide-bladed boasting chisel and a mallet to remove the rough outer layer of a quarried stone. This process shapes the block close to its final dimensions before detailed carving or smoothing begins. It leaves a distinctive pattern of parallel tool marks across the stone face.
I need you to boast those corner blocks down to size before we start laying the first course.
Keep the chisel at a consistent angle to avoid digging too deep and ruining the face of the stone.
Also heard as
- boast out
- rough out
Related terms
Workstone
A dressed block of stone prepared for laying in a masonry structure.
Ashlaring
The short vertical timber framing installed in garrets to cut off the sharp angle where the roof meets the floor.
Stereotomy
The geometric art and science of cutting solid stone into precise shapes for complex architectural structures.