Bronze is a difficult material to pour (stringy), brass and stainless pour easily. No surprise manufacturers don't want to pour it.
Ditto ... 'gas' bubble pockets/blow-outs too, unless the inlet/outlet 'sprues' of the mold are engineered to 'perfect'. Most 'true' bronzes are very
difficult to machine (re. threads, etc.). But that is all ancient metallurgy
BRASSES THAT ARE NOT SUBJECT TO DE-ZINCING.
Just like true-bronzes that are formulated without tin such as NickelAluminum Bronze, there are various available forms of BRASS, with zinc, that are anti-de-zincable (DZR or DR)
brasses that are alloyed with 'transitional metals' such as Tellurium, Selenium, Tantalum, Niobium, Arsenic
, etc. that changes the entire molecular (grain) structure which in turn inactivates and prevents the de-zinc-ability of the brass. These formulations and 'sequences' were closely held proprietary secrets. Its going to take a very long time for asian foundries to recover them; hence, the current problem of zinc loss from asian produced DRZ brass. These DZR alloys were originally discovered/formulated in the ~1950s-1960s for critical navy, aerospace and chemical engineering applications. Their current usage is quite widespread
, despite the almost total forced
collapse of the US 'red metals' industry and other domestic 'foundry' activities.
Here's a brief technical explanation of how these 'de-zincing' BRASSES
are formulated: http://www.jomarvalve.com/docs/lit-jv-dzr.pdf
Here's a bronze without
tin and without the typical trace zinc that aids 'machinability' ... I worked for of the original discoverers of this alloy at that time as a student intern bench chemist (at Phila. Bronze & Brass Corp. / AMCO Metals): Alloy: C95500 Nickel Aluminum Bronze - Concast Metals