Puddling is an obsolete metallurgical process where pig iron is melted in a reverberatory furnace and stirred manually with long iron rods to expose it to oxygen. As the carbon burns off, the melting point of the iron rises, causing it to precipitate out as a spongy, pasty mass. This method allowed large-scale production of high-quality wrought iron without using charcoal.
Heard on the job
The physical toll of puddling was so high that few men lasted past forty at the furnace.
Related terms
Puddle ball
A spongy mass of hot wrought iron gathered from a puddling furnace.
Pig iron
The crude, high-carbon iron tapped directly from a blast furnace.
Iron
A base metal element and the primary constituent of steel and cast iron.
Reverberate
To heat metal by reflecting flames and hot gases down from the furnace roof.