Slaggy or vitreous masses of coal ash Clinkers form the area of naturally burning coal fires and are later exposed by erosion
Powdered cement, produced by heating a properly proportioned mixture of finely ground raw materials (calcium carbonate, silica, alumina, and iron oxide) in a kiln to a temperature of about 2,700oF
Or clencher; Hull planking running fore-and-aft with the lower edge of each strake overlapping outboard the upper edge of the plank below it Clinker strakes are usually secured to each other by nails with roved heads (i e the nail ends have a flat washer placed over them and are then mushroomed over with a hammer) See carvel