V-pro discussion

[Roger Jolly]

>Sand cast plates have a harder shell. This harder "shell" gives a better
>termination and reflective quality to the sound energy.....
>
Hi Mark,
            The grey cast iron also has a high free carbon content, floats
around inside the composite as crystals of carbon.
two things about this free carbon.
I. it makes this quality of cast iron sort of self lubricating.
2. the rate of cooling, effects the crystline structure of the carbon and
hence the amount of internal stress within the plate. The best plates
slowly reduce the temperature over a 24hr period to give the best carbon
structure and the least amount of internal stress.
Regards Roger
P.S. Glad to see you down under safe and sound. It was pleasure meeting you
in KC.
Roger Jolly
Baldwin Yamaha Piano Centre
Saskatoon and Regina
Saskatchewan, Canada.
306-665-0213
Fax 652-0505