I was 'doing it' for a good deal longer than 22 years, and I wouldn't have
liked you to use that method in my business. As I say elsewhere, a bit of
'judicious tapping' is an esssential part of fault finding (particularly
with an intermittent problem) on some equipment but certainly not a 'good
whack' on the casing. I speak as someone who began his technical life as a
'valve tapper', so I know all about 'impact maintenance', but you have to
draw the line somewhere ;)

Said tongue in cheek, however sometimes a dry joint does need a good slap
to get it to show it self. We are not talking about hitting it with a
hammer. Also depends what your fault finding on.

Dave

--

Some people use windows, others have a life.