My guess is that is is water-soluble organic flux. If so, then it should be
washed off
the board with hot water.

For long term reliability, fluxes should be removed anyway. Regular rosin
flux needs to be
removed as well, but requires solvents to do it.

The water soluable flux was designed to eliminate the need for solvents,
which might cause
air quality or environmental issues.

-- Tom



"Mike Knudsen" wrote in message
...
I just received the following from a friend who has been building
electronic
circuits for his home pipe organ (talk about boat anchors). He got shorts
in a
solid state circuit, so imagine what the new solder he describes would do
in
high-impedance tube gear!

Apparently some solder makers are using a new "organic" flux that cleans
off PC
boards easier, but is conductive. I quote:

At the point that I had completed 5 of these, I ran out of my usual spool
of
Kester solder and began using another (spool of Kester solder). I recall
that
the odor of the melting flux was strange and different than that of the
older
spool.

Now I discover that the flux residue on the new spool is CONDUCTIVE! It's
easy
to discern the difference between the old and the new: the earlier
"rosin"
material was yellowish and hard, and when you picked at the edges of it,
it
would break off in hard granules. The new residue is clear and soft,
about the
consistency of ear wax. (The label on the spool says that the flux is
"Organic," so perhaps it *is* ear wax.)
(end quote)
--Mike K.

Oscar loves trash, but hates Spam! Delete him to reply to me.