Caulking is a term applied in ship-building to the driving of a quantity of oakum, saturated with tar, into the seams between the planks of ships, which is effected by a blunt chisel and a mallet. After the oakum has been driven very hard into the seams, it is covered with hot melted pitch or resin, to preserve it against the effects of the water. The term caulking is, however, now extensively applied to other operations of a similar nature; thus engineers in closing up the junctures between the flanges of pipes or plates of iron, caulk them with iron cement.