"John" wrote in message
...

snip
About the same time a lot of continental copper pipe was imported to
overcome the shortages but which seems to have had particles of some
corrodible metal in it. Over the years these have corroded away and
formed
pinholes. The trade used it in good faith and found out afterwards what
crap it really was. Some lengths had one particle in them somewhere and
some lengths have revealed a great number of them which produces,
eventually, something akin to a watering can spreader bar for putting
weedkiller on the lawn!

Also known as "what is that hissing noise and why is the floor wet?" :-(