puddling

 The process of working clay, loam, pulverized ore, etc., with water, to render it compact, or impervious to liquids; also, the process of rendering anything impervious to liquids by means of puddled material.  [1913 Webster]

 The art or process of converting cast iron into wrought iron or steel by subjecting it to intense heat and frequent stirring in a reverberatory furnace in the presence of oxidizing substances, by which it is freed from a portion of its carbon and other impurities.  [1913 Webster]