In article ,
Doctor Evil wrote:
Hi Doctor Evil, if you quench the tube straight away, it makes it easier
to clean off the black oxide, however the annealing effect will happen
anyway if you just let the tube cool. This is much slower, though.
Quenching of steel, for instance, is a different matter.

To anneal properly you quench in water immedaitely.

How can someone who claims to be a heating engineer have so little
practical experience?

And his invoices must be a source of amusement to the lawyers...

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*The statement below is true.

Dave Plowman London SW
To e-mail, change noise into sound.