Warning -- bad new type of solder flux
 

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.

Mike Knudsen wrote:

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!

Several years ago I worked on some sat com equipment that used this stuff.
Miserable stuff. The synth circuits went bananas. I spent many hours cleaning
boards up and resoldering with "real" solder.

Bob WB0POQ

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.

Mike Knudsen wrote:
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!

It works fine.

The new organic fluxes are basically the same thing as the old acid flux
materials, just more soluble.

They can be removed with a water wash rather than with toxic solvents,
but they MUST be removed. If you do not deflux, they will corrode and
destroy the electronics.

A standard household dishwasher will work for defluxing boards.

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.)

Tell your friend to read the data sheet on the solder next time before
buying it. The Kester data sheets have all sorts of warnings about
this and about the importance of defluxing.

These are very popular for mass production applications, because they can
be defluxed very easily. This is a big win for high-Z circuits. But you
must deflux.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Hi Mike,

That is the new (10 years old - new) almost environmentally correct
solder flux. It is citrus based (IIRC) and is meant to be washed off
the board with hot water and detergent. Do that and it is the simplest
stuff to use.

I don't use it, though, because its fumes stink so bad that I am sure
they must be bad for me. So I continue to use rosin core solder, and
then use isopropyl alcohol to remove the flux.

You shouldn't leave flux on any solder joint. If you are steadfastly
determined to do so anyway, there are several fluxes available in the
Kester solder line that leave a very minimal amount of residue.

-Chuck Harris

Mike Knudsen wrote:
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.

Nothing beats good ol' Kester "44" ;-)

--
Gregg
*It's probably useful, even if it can't be SPICE'd*
http://geek.scorpiorising.ca

In article , Chuck Harris
writes:

That is the new (10 years old - new) almost environmentally correct
solder flux. It is citrus based (IIRC) and is meant to be washed off
the board with hot water and detergent. Do that and it is the simplest
stuff to use.

I knew it had to do with defluxing in a less polluting way. I had heard back
then at Bell Labs that someone had come up with a citrus-based defluxing agent
that worked on the usual rosin flux, but I must have heard it wrong.

I don't use it, though, because its fumes stink so bad that I am sure
they must be bad for me. So I continue to use rosin core solder, and
then use isopropyl alcohol to remove the flux.

I have no idea what burning orange peels smell like, though I'm sure kids tried
smoking them back in the 60s, along with banana peels :-)

You shouldn't leave flux on any solder joint. If you are steadfastly
determined to do so anyway, there are several fluxes available in the
Kester solder line that leave a very minimal amount of residue.

Surely you're not saying one should deflux a tube socket, wired chassis solder
joint? I can see defluxing PC boards, but I've never heard of defluxing a BA
style solder joint, and it would be downright near impossible. Well, maybe
with a dozen Q-Tips and an hour of work. Did factories deflux BA chassis?

Anyway, my buddy swore he'd deflux things now. And he'll be more careful to
read the label before buying any solder. --Mike K.
Oscar loves trash, but hates Spam! Delete him to reply to me.

Hi Mike,

I have seen it both ways in old tube gear. I have seen plenty
of mil gear that was defluxed. I have seen plenty of consumer
gear that wasn't.

The process of defluxing involved dipping or spraying the chassis
in carbon tetrachloride, or later trichlorethylene. Flux comes off
easily when it is fresh.

I wash all joints I make, be they PC board, or otherwise with
isopropyl alcohol and a brush. If I can reach the joint with a
soldering iron, I can reach it to deflux it.

-Chuck Harris

Mike Knudsen wrote:

Surely you're not saying one should deflux a tube socket, wired chassis solder
joint? I can see defluxing PC boards, but I've never heard of defluxing a BA
style solder joint, and it would be downright near impossible. Well, maybe
with a dozen Q-Tips and an hour of work. Did factories deflux BA chassis?

Anyway, my buddy swore he'd deflux things now. And he'll be more careful to
read the label before buying any solder. --Mike K.
Oscar loves trash, but hates Spam! Delete him to reply to me.

Mike Knudsen wrote:
In article , Chuck Harris
writes:

That is the new (10 years old - new) almost environmentally correct
solder flux. It is citrus based (IIRC) and is meant to be washed off
the board with hot water and detergent. Do that and it is the simplest
stuff to use.

I knew it had to do with defluxing in a less polluting way. I had heard back
then at Bell Labs that someone had come up with a citrus-based defluxing agent
that worked on the usual rosin flux, but I must have heard it wrong.

Someone has. We use it at work, and it's okay. It's nowhere near as
effective as the fluorocarbon stuff. It's definitely more effective than
isopropanol.

I don't normally mind defluxing with isopropanol, although it can take a
lot of elbow grease. But it can be a problem for very-high-Z stuff like
condenser mike front ends, and of course it's impossible in a production
environment.

Surely you're not saying one should deflux a tube socket, wired chassis solder
joint? I can see defluxing PC boards, but I've never heard of defluxing a BA
style solder joint, and it would be downright near impossible. Well, maybe
with a dozen Q-Tips and an hour of work. Did factories deflux BA chassis?

Not often, but sometimes you will see terminal board construction that has
been defluxed, especially on old military radios which would be used in
wet environments. They used to have dip tanks for the job, although today
a spray can of Flux-Off would do the job nicely.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Mike Knudsen wrote:
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.

Mike:
Many of the older acid fluxes were highly conductive but most of the newer
ones are not - some are even no-clean fluxes that don't have to be cleaned
up at all.

--
Brian Denley
http://home.comcast.net/~b.denley/index.html