How to do a Basic Wire Splice

Its not exactly interlaced. Not twisted though. Spread strands pushed together like pushing 2 brushes together.
When stranded wire is tightly twisted the same few strands cover the outer contacting surface. Solder may not flow all through it.
If you are repairing a broken wire in a group of wires like automotive harness. Keep the splice short as possible. If you strip and overlap a lot of wire length that wire ends up that much shorter than the others. Closer to a harness connector you are the more stress applied at that terminal.