[Elecraft] Deflux?

[Stuart Rohre]

The "BEST" low flux residue solder I have used in the past 45 years plus of
soldering is Multicore, a brand that originated in England, and now is made
in Richardson, TX among many locations.  Their claim to fame is the use of
small amounts of flux distributed in 5 cores thru the solder wire, thus; you
do not need much solder and flux to get a nicely wetted joint.

Their SAVBIT alloy also has a constituent that cuts the corrosion of copper
tips and plating.

One pound box of it lasted my about 20 years.
72,
Stuart K5KVH