In bronze sculpture, a technique for joining separately cast parts or repairs, or filling casting defects, by adding an alloy with a high melting point that is close in composition to that of the primary cast metal. A proper weld involves temperatures high enough to allow partial melting and fusion of both the welding metal (referred to as secondary cast) and the surrounding primary cast.
In a technique very specific to antique large bronzes, poured molten bronze is used as the source of heat for joining separately cast sections or securing repairs, instead of modern techniques using blow-torch or TIG and MIG (see vol.1, ch. 5). It acts both as a filler metal and as the main source of heat (video 7). This process is known as flow welding or flow fusion welding.