Thanks for the two responses. To add detail to my original post, I should add that to prevent the 'joiner' spring migrating into either end of the main spring during operation, a single spring coil from a donor main spring was cut and soldered to the middle of the joiner. When joining the...
The spring is 1m long, close coiled, Ø6.0mm OD Ø1.0mm wire and made from C51000 Phosphor Bronze, 5% Grade "A" Spring Temper H08.
It is joined with a 'spring' made from the same material that is 30mm long and Ø4.27mm OD (to be a tight fit when 'screwed' into the Ø6.0mm spring).
The assembled band...
