[Elecraft] "No-clean" solder.

[Ron D'Eau Claire]

Ken wrote:
In 1999 or so when I purchased K2 #320 the Kester "No-clean' solder was 
recommended by Elecraft.

I quote from a April 12 1999 message on the reflector by Wayne N6KR titled 
"Correction on Kester solder part numbers"...

Many other posts at this time also recommended the 245 "no-clean". I used 
this solder on my kit and it still works.

--------------------------------

The 245 flux is a variation on the safe, time-proven 44 rosin flux. While it
may provide less residue on finished joints and shouldn't cause any
long-term problems, it's not clear that it produces a "better" solder joint.


>From the Kester data sheet: 

"Kester 245 No-clean Cored Wire was developed to complement low residue
liquid fluxes being used by the electronics industry. The chemistry is based
on some of the same principles that have been safely used for years in
mildly activated rosin fluxes. The use of 245 No-clean Cored Wire results in
visually acceptable assemblies without cleaning, yet soldering quality and
efficiency is comparable to that obtained with mildly activated rosin flux."
(http://tinyurl.com/ach76)

The Kester #44 currently recommended is the "original" type of wire solder
with rosin flux that has been around for many years. Kester has this to say
about it:

"Kester 44 Rosin Flux is an activated rosin formula for use in flux-cored
solder wire. Kester 44 Rosin Flux has virtually dominated the field of
activated rosin core solders for well over four decades. An outstanding
performance feature of this flux is the "instant-action" wetting behavior.
The high mobility and fast-spreading action of this flux results in more
reliable production line soldering....When exposed to an elevated
temperature and humidity environment (38°C, 94% RH) for
72 hours, there is no evidence of corrosion caused by the flux residue.
Throughout its many years of wide usage, 44 Rosin Flux has produced many
billions of soldered connections. In all these billions of solder joints,
involving the most delicate and critical of electrical and electronic
components, there has never been an authentic instance of corrosion by the
flux residue under normal conditions of use." (http://tinyurl.com/8nqrx)


Ron AC7AC