[Bell Historians] Tin Loss (Was Devon Bells)
david1.beacham at gJU-2OC2De4OFZbro6yA5-sTUv_hnfSy4ArNMLvivVVdLKmRe5cUEqpjTYo2VuFXuWB5PhxHQPGTvfaXngJGmAd5sg.yahoo.invalid
Sat Jan 20 20:09:32 GMT 2007
I have long been sceptical about the amount of tin that may be lost "up the chimney" during the meting process. I could not see how something costing several thousands pounds per ton could be "lost" without some effort being made to prevent or recover it. In 1976, I wrote to the Tin Research Institute and asked their opinion. I quote the following from their reply:
"The molten metal is usually tapped from the furnace into a ladle at approx 1100 degrees C, and poured at a slightly lower temperature. Since the boiling point of tin is 2267 degrees, any loss of tin ocurring will be the result of oxidation rather than volatilisation. The rate of oxidation of the tin will depend on the furnace conditions, but if a charcoal cover on the melt is used, any tin oxide present will be reduced to tin, avoiding any tin losses."
----- Original Message -----
From: Richard Offen
To: bellhistorians at yahoogroups.com
Sent: Saturday, January 20, 2007 2:45 PM
Subject: [Bell Historians] Re: Devon Bells
> Back in the days of itinerant bellfounders, bell casting was done on
> the spot - often in the churchyard or even the base of the tower. So
> all available metal from old bells was re-used in the process, as a
> simple matter of economy. That's where the term "recast" comes from.
Even then, as has been said before here, most of the tin will have gone
up the furnace chimney and had to be replaced with new metal!
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