So I stand by my statement that there is virtually no loss of tin by evaporation at the melting temperature of the bronze.
We have historical evidence to confirm this statement.
Russians are renown for having casted really large bells. The
technique was to prepare mold, which was buried in the ground, but the
top was completely open. Bronze was melted in multiple pots located
around the mold perimeter, and all these pots were emptied into mold
simultaneously.
Any caster would see the problem with this method, so to overcome the
problem of premature cooling, bronze was brought to much higher
temperatures than would be necessary with conventional pour.
Russians used 78% copper and 22% tin, an alloy with greater potential
for evaporation, if it would be a factor. We know that bronze was
remelted many times, because not every casting attempts was
successful, so bronze was reused. All historical bell actually
indicate how many attempts it took to cast it. Famous Tzar Bell is
actually known as Tzar Bell III.
Peter the Great, in preparation to war with Sweden ( Great Northern
War ) ordered to remelt all bronze bells into gun barrels, and these
guns performed beautifully, as evidenced by historical accounts. And
what could be a better test to the soundness of an alloy as using it
for gun barrel.
Leonid Surpin