Malc, the scrappie called round today and brought a tool to show me that he's picked up.

It consists of two hardened punches and a tension spring, what you can't see is that one punch is longer that the other inside the spring and they are touching at the internal ends.
It's an automatic centre punch, you put one end on the mark and pull the other end to expand the spring and let go.
Depending on which end you pull determines the weight of the pop mark due to the differing weights.
So simple and fool proof after these normal sort we are used to that never bloody work or if they do the pop mark is so minute it's a joke.
John S.
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