puddlers

Puddlers were skilled workers in the puddling process, a method of refining pig iron into wrought iron that was widely used in Britain from the late 18th century into the mid-19th century. The process took place in a reverberatory furnace where melted pig iron, produced from coke-smelted ore, was exposed to air to burn off carbon and other impurities, producing wrought iron with a lower carbon content. The puddlers' task was to stir and manipulate the molten metal using long-handled rods and paddles, breaking up slag and encouraging oxidation. A typical cycle produced a spongy mass or ball of refined iron called a sow, which would be collected and remelted or further processed. After several puddling passes, the iron could be rolled and hammered into bars, rails, or other shapes.

Puddlers were among the better-paid and more skilled workers in early ironworks, requiring strength, dexterity, and experience to maintain a steady heat, control the oxidation, and manage the evolving slag. The work was physically demanding and dangerous, and puddlers often organized into work gangs or unions seeking improvements in pay and conditions. The puddling process and the related rolling mills were central to the expansion of British iron production during the Industrial Revolution and helped enable larger-scale construction and infrastructure.

The use of puddling declined as newer metallurgical methods, such as the Bessemer and open-hearth processes, and later basic oxygen steelmaking, offered more efficient ways to produce iron and steel. The term "puddler" remains a historical reference to this phase of ironmaking. See also puddling process, Henry Cort.