In article ,
Eli the Bearded wrote:


I still have, purchased around 1990, some Archer 64-005 solder. It's
60/40, 0.032" (about 0.8 mm, finer than typical) "rosin core". I'm
running out of it, but that's been my go-to electronics solder since I
bought it. I have a 23W / 33W swappable pencil soldering iron from the
same period (and also Radio Shack). It has served me well, but I have
been thinking maybe time for an upgrade. For one thing, I've never
really been able to work with silver solder easily.

Years ago I moved up from a cheap non-regulated soldering pencil, to a
Weller WTCP-series (with the ferromagnetic-tip switch) and found it
quite an improvement. More recently I bought a used Metcal, and find
it very worthwhile... fast to heat, doesn't overheat, and the tip
temperature recovers quickly.

I still use a propane-fired pen, or one of a couple of Weller
soldering irons for some jobs, but the Metcal is my go-to for PCB
work.

The advantage of 63/37 is what? Just lower melting point? Anything else?
I know it is the "eutectic" point (ratio with lowest possible melting
point), but I don't know if that conveys other desirable traits.

The whole eutectic alloy freezes (and melts) at a single temperature,
so the molten mass cools to a solid as a whole, rather than going
through a "slushy" temperature range (the slush being a mix of
solidified crystals and liquid) as 60/40 does. This can (I
understand) reduce the risk of a "cold" solder joint where the joint
was moved while the solder was solidifying.