On Sat, 23 Aug 2008 01:12:52 +0100, Andy Wade
wrote:

T i m wrote:

I tried putting it in the lathe earlier but it's just too unstable to
be reliable (and I've images of it flying across the workshop, never
to be seen again) :-(

The trick for machining rubber is to cool it down to about -50 deg C
first (then work quickly). I've seen this done and it's very effective,
but the trouble is that a small workpiece like yours will probably warm
up too quickly for the technique to be useful.

Freezer spray or a Peltier cooler module from RS will get you down to
somewhere near the target temperature.

Thanks Andy but I think it will be easer to buy a new valve (as
interesting an experiment it would be etc). ;-)

I haven't yet though ... still waiting to stumble on that perfect
rubber item to be a replacement valve ...

All the best ..

T i m