You cant tin these painted wires, they wont hold the solder at all. However the connection is pretty solid, I have strain reliefs 3-4 times. one clamping the wire, heatshrink over that wire, then heatshrink on the spring strain relief, then another heatshrink over the whole connector. I also lined that last heatshrink with some adhesive underneath. overkill? probably.Should've tinned the wires. It would hold better.
either way it worked out fine, i tugged on it big time, i got no shorts or signs of stressingI've tinned wire really small before that had a coating/insulation on them. I used a magnifiying glass and a razor blade.