Guidelines for the Technical Examination of Bronze Sculpture

**Table 6**
**Main properties of different copper alloys used for bronze sculpture**
Castability ratings are based on Schmidt and Schmidt 1992, 1155; weldability ratings are based on Rogers 1993, 1874; color names are based on Tyler and Black 1992, 815. All contents in weight %.
	melting temperature	castability	machinability	weldability (fusion welding)	ability for fire gilding	ability for chemical patina	corrosion resistance in air	color
unalloyed copper	high	poor	poor	poor	good	good	poor	soft pink
arsenical alloy (e.g., 3% As)	medium	medium	?	?	?	?	?	soft pink
tin-bronze (e.g., 10% Sn)	medium	medium	poor	good	medium	poor	good	bronze-gold
zinc-containing alloy (e.g., 15% Zn)	medium	medium	poor	poor	medium	medium	medium	gold
leaded alloy (e.g., 10% Sn & Pb)	medium	good	good	depends on other additions	poor	depends on other additions	depends on other additions	bronze-gold
phosphor bronze (e.g., 0.02% P)	high	good	poor	excellent	good	good	poor	soft pink
silicon bronze (e.g., 4% Si)	medium	good	medium	excellent	?	poor	excellent	gold

Table 6: Main properties of different copper alloys used for bronze sculpture