A 19th century shipwright's calking seat, containing a lignum vitae mallet head and 12 steel caulking irons.

A number of the irons have marks of Sheffield and Glasgow tool makers.

Width: 40 cm.

Depth: 21 cm.

Height: 24.5 cm.

Caulking (also spelled calking) on wooden vessels uses fibres of cotton and oakum (hemp fibre soaked in pine tar). These fibres are driven into the wedge-shaped seam between planks, with a caulking mallet and a broad chisel-like tool called a caulking iron. The caulking is then covered over with a putty, in the case of hull seams, or else in deck seams with melted pine pitch, in a process referred to as paying, or "calefaction".