On Fri, 21 Aug 2009 13:42:40 -0700 (PDT), NT
wrote:

What makes you think their immersion heater cable may be dangerous?

Sorry, I thought you said in your earlier answer that even a 90 degree
rated PVC cable might overheat when connected to an immersion heater,
implying that PVC should not be used for this purpose?

What happens to butyl and PVC cables when they overheat?

Short term pvc goes very soft, conductors migrate through it, and
fires tend to happen. Long term is hardens and falls apart
Rubber suffers no ill effect short term, long term it hardens and
breaks.

So rubber has benefits in the short term but long term prospects are
bad with either?

BTW, how accurate are the thermostats? If set to 60C will I get 60C,
or 55-65C, or 50-70C, etc? I know I am supposed to set it to 60C to
kill all the bugs, will that be high enough?

Thanks again.