On 01/04/18 18:30, David wrote:
So I think I should rephrase the question into "how much power am I likely
to need to spot heat this kind of structure".

It's less power, than a very large bit, that wont cool down immediately
it hits that ring


--
Those who want slavery should have the grace to name it by its proper
name. They must face the full meaning of that which they are advocating
or condoning; the full, exact, specific meaning of collectivism, of its
logical implications, of the principles upon which it is based, and of
the ultimate consequences to which these principles will lead. They must
face it, then decide whether this is what they want or not.

Ayn Rand.