Hello, Doug, Uniformly soldering twisted wire is a challenge. The
problem lies in the nature of the twisted wire itself. Silver solder,
as you know, will not bridge gaps. Metal must be in contact with metal
for the solder to flow along the joint. Yet twisted wire presents a
whole series of gaps - each time one wire meets another. A sawtooth
pattern, seen in profile. If you put on enough solder to jump the gaps
and make the joint it’ll also flow into and fill up the interstices
between the wires and greatly lessen the twisted effect.
The solution that works best for me is to simply file the twisted
wire flat where the joint is to be made. In other words if you’re
soldering it onto a backing plate file the bottom of the wire flat.
This removes the raised-and-lowered succession such that the entire
wire lies flat on the plate and the solder is not presented with any
gaps to jump. If it is to be soldered to the bezel, file the inside
flat. In other words I approach it not as a question of heat control
or solder use, but rather as an issue of joint preparation, of fit-up.
A corollary benefit of this approach is that with a flat-contact
joint you need very little solder, hence there is less solder flow
into the interstices of the twist, which therefore remains better