Best bang for your buck...

[obseq]

What casting alloy(s) offer the best both worlds--Both affordable and resilient?

I know that bronze is notoriously expensive to work with but I am hearing that more affordable alternatives are often a better choice.

[jwebb]

Alloy selection, whether for sculpture or for industrial applications, is a matter of considering a bunch of "trade-offs" in properties. High tensile strength sacrifices ductility (i.e., stronger metal is more brittle), corrosion resistance often sacrifices hardness, etc. The intended environment, Costs, surface character, and "castability" also have to be considered. Maybe "machinability" and "weldability" also, if applicable. "Castability" is a complex and somewhat arbitrary evaluation of the fluidity of the alloy in relation to the configuration and wall thicknesses desired; the amount and complexity of gating needed; the resistance to hot tearing during solidification; volumetric shrinkage during solidification; reaction in the molten state with various atmospheres and funace and mold materials; and maybe other factors particular to a given foundry. There are actually "castability ratings" assigned to various alloys by people like the Investment Casting Institute. Having said all that, for sculpture, the sheer visual appeal of one material over another may override all of the above, and is solely in the eye of the sculptor. There's a wide variety of beautiful work out there. But, in my opinion manganese bronze is still the best, most beautiful, most versatile, and in the long run the best bargain.

[Toby]

Casting aluminium can be anodised to most colours, weighs a fraction of bronze, melts at 650 centigrade or thereabouts, forms a weatherproof oxide layer and is readily found as scrap. Use casting grades, with silicon added as the more ductile/malleable grades don't cast so nice. Can be melted in a steel pot with little or no porosity in finished casting.
Best: engine heads, gearbox casings, pistons
Ok: Lawnmower decks, food slicers
NO no no: Aluminium tube, beercans, deck chairs, extruded section, bicycle frames.
The statue in Piccadilly Circus, London of some bloke with wings is aluminium.
Napoleon presented his wife Josephine with jewellry made from the newly isolated exotic metal aluminium.
At the moment I cast sculptures and sell them direct to joe public while still making a profit. How? aluminium.. er.. aluminum. :D