Published July 27th 2023

How To Work A Cavetto In Stone

A segmental cavetto mould
A basic segmental cavetto mould

A basic segmental cavetto stone moulding is formed out of a quarter circle, radius a-b.


Steps For Working A Cavetto Mould In Stone

Applying The Template

A cavetto mould applied to the stone
A cavetto mould applied to the stone

The process of working a cavetto begins by marking the template onto the parallel joints of the stone using a scriber. Templates for stone are traditionally made from zinc sheeting.


Working Initial Chamfers

Initial chamfers worked on the stone
Initial chamfers worked on the stone

With the template marked on, chamfers are worked in the stone from each side of the moulding towards the middle. This stage defines the deepest part of the mould, and like all stonework, using a straight edge ensures the mould remains true through the length of the stone with no high or low spots.


Working Further Chamfers

Further chamfers worked on the mould
Further chamfers worked on the mould

Following on from the previous stage the process is repeated to define two more points of the mould. Again, checking the trueness of the worked stone with a straight edge.


Finishing The Cavetto Mould

The finished cavetto mould worked on the stone
The finished cavetto mould worked on the stone

The final process of defining the curve is done with a bullnose using the points at which the previous chamfers meet as guides. Using the bullnose chisel, the curve is worked along its length of the stone and checked with a straight edge for trueness. With the curve now worked it is tooled over with a dummy and bolster following the curve of the mould to remove any flat spots.


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