[TR] soldering

[Randall]

> The solder for electrical joints is not like the solder for 
> other things. It
> has a rosin core.

In addition, practically all plumbing solder these days is lead-free and is
much harder to use (won't wet the surface) than the classic tin/lead solder,
as well as having a higher melting point.  It is also (at least mostly)
non-eutectic, meaning it hardens over a wide temperature range instead of
'freezing' all at one temperature.  This make it much more likely to produce
a 'cold' solder joint.

The plumbing stuff I found at Home Depot has a melting range of 420F to 460F
(meaning it is kind of half-melted between those two temperatures); while
proper eutectic solder melts/hardens at exactly 361.4F

My antique Weller soldering gun is only rated at 120W, and I haven't found
an electrical joint yet that it can't handle, including soldering wires to
steel sheet metal chassis.

A secret that my Dad taught me years ago : The output of those Weller guns
will fall off over time.  You can get it back by loosening and then firmly
retightening the two nuts that hold the tip to the gun.

The soldering gun tip also erodes with usage and occasionally needs to be
dressed back to it's original chisel shape, and re-tinned.  Using an eroded
or poorly tinned tip will greatly reduce heat transfer to the joint.  Once
the chisel part is gone, you need a new tip.

Could be my imagination, but I also feel that the classic Kester "44" solder
works better than the no-name rosin core stuff they sell at Radio Shack.
Looks like I'm not the only one:
http://goo.gl/IU3I7

-- Randall