Andy Dingley wrote:
On 17 Oct, 18:41, Bill wrote:

Towards the end of the 5 years the copper tubes started to fall off.
Inspection showed that the solder had changed to what looked like a
crystalline form - sort of like a really terrible dry joint, but much
more obvious.

Web search for "grey tin", and the story of how Napoleon was defeated
in Russia because his army's trousers fell down.

Hmm Wiki states that bismuth or antimony may be used instead of lead.
Bit they are ,are they not, aabout 1000 times deadlier than lead?