Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

In article
,
hooch wrote:

Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

Q-tips and isopropyl alcohol seems to be the widely accepted method.

"Smitty Two" wrote in message
news
In article
,
hooch wrote:

Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

Q-tips and isopropyl alcohol seems to be the widely accepted method.

I use a proprietary aerosol defluxer made by Electrolube, applied with an
old toothbrush. Has worked well for me for years.

Arfa

On Nov 27, 4:24 am, "Arfa Daily" wrote:
"Smitty Two" wrote in message

news
In article
,
hooch wrote:

Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

Q-tips and isopropyl alcohol seems to be the widely accepted method.

I use a proprietary aerosol defluxer made by Electrolube, applied with an
old toothbrush. Has worked well for me for years.

Arfa

I brush the area lightly with a soft toothbrush dipped in isoproyl
alcohol to remove the flux and then dab with a Q tip or lint free
cloth to dry out the area. The toothbrush tends to spatter if you
brush too hard so cover the surrounding area if the flux build up is
large
arunwad

On Nov 27, 1:00 am, hooch wrote:
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

Flux remover and cotton swabs. If it's in a spray can, I wouldn't
recommend spraying it - it can make a tacky mess.

"Smitty Two" wrote in message
news
In article


m,
hooch wrote:

Any suggestions for the best way to remove old flux from
circuit
boards when desoldering? The wick soaks up the solder just
fine, but
the flux seems to remain behind.

Q-tips and isopropyl alcohol seems to be the widely accepted
method.


what % isopropyl do you use ? if it is greater than 90% drug
store variety where does one fidn such isopropyl ?

i have use the 90% variety and it seems to leave a residue .

robb

I've used paint thinner or laquer thinner...alcohol sometimes leaves a
white residue


"hooch" wrote in message
...
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

On Nov 27, 3:56 pm, "lurk" wrote:
I've used paint thinner or laquer thinner...alcohol sometimes leaves a
white residue

"hooch" wrote in message

...



Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.- Hide quoted text -

- Show quoted text -

I use naptha with good results.

"robb" wrote in message
...

"Smitty Two" wrote in message
news
In article


m,
hooch wrote:

Any suggestions for the best way to remove old flux from
circuit
boards when desoldering? The wick soaks up the solder just
fine, but
the flux seems to remain behind.

Q-tips and isopropyl alcohol seems to be the widely accepted
method.


what % isopropyl do you use ? if it is greater than 90% drug
store variety where does one fidn such isopropyl ?

i have use the 90% variety and it seems to leave a residue .

robb


The IPA that I use is 99.7% and is called "Electronics Grade". I just get it
from my normal trade electronic components supplier. It leaves no
discernable residue in itself, although any will leave a residue if it is
used to dissolve a 'contaminant', and then not fully flushed off the board.

Arfa

"lurk" wrote in message
et...
I've used paint thinner or laquer thinner...alcohol sometimes leaves a
white residue

You're brave ! Do you ever have any trouble with the solder mask or silk
screen overlay dissolving away ?

Arfa

In article ,
"robb" wrote:

"Smitty Two" wrote in message
news
In article


m,
hooch wrote:

Any suggestions for the best way to remove old flux from
circuit
boards when desoldering? The wick soaks up the solder just
fine, but
the flux seems to remain behind.

Q-tips and isopropyl alcohol seems to be the widely accepted
method.


what % isopropyl do you use ? if it is greater than 90% drug
store variety where does one fidn such isopropyl ?

i have use the 90% variety and it seems to leave a residue .

robb

Like Arfa said, 99% +. We usually buy 10 gallons at a time from an
industrial chemical supplier; it's cheap and that's their minimum for
free delivery.

Also agree that the residue is likely not the alcohol itself, but a
component of the flux. I wouldn't worry about a bit of residue. It's
harmless.

On Nov 28, 5:26 am, Smitty Two wrote:
In article ,





"robb" wrote:
"Smitty Two" wrote in message
news
In article


m,
hooch wrote:

Any suggestions for the best way to remove old flux from
circuit
boards when desoldering? The wick soaks up the solder just
fine, but
the flux seems to remain behind.

Q-tips and isopropyl alcohol seems to be the widely accepted
method.

what % isopropyl do you use ? if it is greater than 90% drug
store variety where does one fidn such isopropyl ?

i have use the 90% variety and it seems to leave a residue .

robb

Like Arfa said, 99% +. We usually buy 10 gallons at a time from an
industrial chemical supplier; it's cheap and that's their minimum for
free delivery.

Also agree that the residue is likely not the alcohol itself, but a
component of the flux. I wouldn't worry about a bit of residue. It's
harmless.- Hide quoted text -

Thanks to all for the suggestions. I didn't have anything mentioned
at home so I tried some "Goo Gone" which seemed to work quite well.

"Arfa Daily" wrote in message
...

"lurk" wrote in message
et...
I've used paint thinner or laquer thinner...alcohol
sometimes leaves a
white residue

You're brave ! Do you ever have any trouble with the solder
mask or silk
screen overlay dissolving away ?

Arfa

I was thinking same thing.

maybe now i can try my *brake cleaner* spray it has a (tolulene,
xylene, naptha, acetone) mix that should blast just about any
residue off ? (just joking) i would not try it on any useful
board probably melt the components off

robb

On Nov 28, 4:04 am, "robb" wrote:
"Arfa Daily" wrote in message

...

"lurk" wrote in message
. net...
I've used paint thinner or laquer thinner...alcohol
sometimes leaves a
white residue

You're brave ! Do you ever have any trouble with the solder
mask or silk
screen overlay dissolving away ?

Arfa

I was thinking same thing.

maybe now i can try my *brake cleaner* spray it has a (tolulene,
xylene, naptha, acetone) mix that should blast just about any
residue off ? (just joking) i would not try it on any useful
board probably melt the components off

robb

A few years back we were TRYING to remove silk screen from boards.
Obviously _something_ will dissolve it but we never found what it
might be.

I prefer MG Chemicals 4140 flux remover in 1 litre bottles. Just
bought 4 more today from MarVac for $16 each. It's a mixture of
alcohols that work better that isopropyl and causes no damage to the
components - including styrenes.

GG

"hooch" wrote in message
...
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

some newer flux will wash away with water solvent based cleaners

rubbing alcohol is fine too

flux is non-conductive, residue wont affect anything, except if you
constantly obsess about it and gaze affectionately at your work

i mostly just leave it on, just like the asian mass produced junk we keep
seeing.

aesthetics really dont affect electrical performance!

;-)).

"robb" wrote in message
...

"Arfa Daily" wrote in message
...

"lurk" wrote in message
et...
I've used paint thinner or laquer thinner...alcohol
sometimes leaves a
white residue

You're brave ! Do you ever have any trouble with the solder
mask or silk
screen overlay dissolving away ?

Arfa

I was thinking same thing.

maybe now i can try my *brake cleaner* spray it has a (tolulene,
xylene, naptha, acetone) mix that should blast just about any
residue off ? (just joking) i would not try it on any useful
board probably melt the components off

robb



using those other solvents often softens insulatons and migrates into
components. BAD BAD BAD!

is it fun to see your handy work light up in flames?

breath deeply, you might get a rush too!

"HapticZ" wrote in message
. net...

"hooch" wrote in message
...
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

some newer flux will wash away with water solvent based cleaners

rubbing alcohol is fine too

flux is non-conductive, residue wont affect anything, except if you
constantly obsess about it and gaze affectionately at your work

i mostly just leave it on, just like the asian mass produced junk we keep
seeing.

aesthetics really dont affect electrical performance!

;-)).


Now you see, I just can't do that ! It's ingrained in me. Many years ago, I
was taught as an apprentice, to have a tidy mind, and to leave things as you
found them. My apprentice mentor was one of the best service engineers that
I ever came across - then or now - and he taught me many things that have
served me well throughout my professional career in electronic service work.

One of those things was that the only way anyone should be able to see where
you've replaced a component on a PCB, is if your soldering is *better* than
the factory original, and that involves removing flux residue.

There is a practical side to it as well. When flux is left on a board for
any length of time, something happens to it (so it must still be reacting in
some way ??) such that it becomes a brilliant resister of a soldering iron
tip. I repair some commercial boards that used to be done by a company that
did thoroughly scruffy work, and always left all of the flux on the board,
from where they had replaced components which regularly fail. When I now see
these same boards, the rework vacuum iron, really struggles to remelt the
joints which are covered in flux, against those that are not. It also clogs
up the vacuum tip much more regularly than when I am working on boards that
are flux-free. Perhaps I'm just a sad old pedant on this sort of thing, but
it pleases me to look on good workmanship and practices, and I'm far too
long in the tooth to change now ... d;~}

Arfa

Arfa Daily wrote:
"HapticZ" wrote in message
. net...
"hooch" wrote in message
...
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.
some newer flux will wash away with water solvent based cleaners

rubbing alcohol is fine too

flux is non-conductive, residue wont affect anything, except if you
constantly obsess about it and gaze affectionately at your work

i mostly just leave it on, just like the asian mass produced junk we keep
seeing.

aesthetics really dont affect electrical performance!

;-)).


Now you see, I just can't do that ! It's ingrained in me. Many years ago, I
was taught as an apprentice, to have a tidy mind, and to leave things as you
found them. My apprentice mentor was one of the best service engineers that
I ever came across - then or now - and he taught me many things that have
served me well throughout my professional career in electronic service work.

One of those things was that the only way anyone should be able to see where
you've replaced a component on a PCB, is if your soldering is *better* than
the factory original, and that involves removing flux residue.

There is a practical side to it as well. When flux is left on a board for
any length of time, something happens to it (so it must still be reacting in
some way ??) such that it becomes a brilliant resister of a soldering iron
tip. I repair some commercial boards that used to be done by a company that
did thoroughly scruffy work, and always left all of the flux on the board,
from where they had replaced components which regularly fail. When I now see
these same boards, the rework vacuum iron, really struggles to remelt the
joints which are covered in flux, against those that are not. It also clogs
up the vacuum tip much more regularly than when I am working on boards that
are flux-free. Perhaps I'm just a sad old pedant on this sort of thing, but
it pleases me to look on good workmanship and practices, and I'm far too
long in the tooth to change now ... d;~}

Arfa

In the old days (late-60's / early 70s for me), we used MEK and a
short-bristled brush (a plumber's acid/flux brush with the bristles cut
down). Yes, we used it indoors, and yes, we used it all day, and no, to
my knowledge no one suffered any effects from it. Every tech and every
engineer had a small pot of it on his bench with a self-closing lid,
which reduced the exposure, and he opened the pot, dipped the brush, and
cleaned each solder joint as he made it. Later, when we started using
small wave-soldered boards, each board was cleaned in the same way after
it came out of the solder bath / trimmer station. It was the only way
that inspection of the board could happen. By the way, this was not
Joe's Garage shop - this was Motorola, and we were inventing/building
the HT-220 Handie-Talkie.

MEK is still available over-the-counter at Sherwin-Williams paint
stores, for example.

Bill

On Nov 27, 12:00 am, hooch wrote:
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

If you are covering a large area, use a paint brush thats about an
inch wide, cut the bristles about an inch long (till they feel stiff,
maybe shorter), dip in alcohol and it will scrub it till its like new.

yes, i do appreciate your position. looking back to gear i fixed, (if it
still even exists, most long gone to the recycle ) it wasnt any trouble as i
used basic needle point 10/20/30 watt irons and loupes. nothing really
commercial, just fix-it immediately and get it into service. i usually
never saw the same gadget twice again!

if somethng/device is so prone to failure, then the design was poor and we
got soemthing that failed less or never again

quality in the workmanship is key to success as the units get brutally
handled and .criticized by the end users. & some people expect laptops to
survive being run over by a car, its just crazy!

cleanliness is indeed closer to godliness, it is easier to verify work done,
good/bad joints and just for prettiness too

i have often used the onboard left over flux to assist the new solder work,
yep, u can call me cheeep, i dont care.

i do admire the slick screen printed masks, fully labelled component,
location grids, section function layot delineators and so forth too. but
thats for those companies the have 5000 designers, techs and worldwide
distribution networks to play with. along with millions of buks to
squander!

the end result is, do good , reliable , and safe work. that will keep u
your job ( maybe) and reinforce your self -respect too.




"Arfa Daily" wrote in message
...

"HapticZ" wrote in message
. net...

"hooch" wrote in message

...
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

some newer flux will wash away with water solvent based cleaners

rubbing alcohol is fine too

flux is non-conductive, residue wont affect anything, except if you
constantly obsess about it and gaze affectionately at your work

i mostly just leave it on, just like the asian mass produced junk we
keep
seeing.

aesthetics really dont affect electrical performance!

;-)).


Now you see, I just can't do that ! It's ingrained in me. Many years ago,
I
was taught as an apprentice, to have a tidy mind, and to leave things as
you
found them. My apprentice mentor was one of the best service engineers
that
I ever came across - then or now - and he taught me many things that have
served me well throughout my professional career in electronic service
work.

One of those things was that the only way anyone should be able to see
where
you've replaced a component on a PCB, is if your soldering is *better*
than
the factory original, and that involves removing flux residue.

There is a practical side to it as well. When flux is left on a board for
any length of time, something happens to it (so it must still be reacting
in
some way ??) such that it becomes a brilliant resister of a soldering iron
tip. I repair some commercial boards that used to be done by a company
that
did thoroughly scruffy work, and always left all of the flux on the board,
from where they had replaced components which regularly fail. When I now
see
these same boards, the rework vacuum iron, really struggles to remelt the
joints which are covered in flux, against those that are not. It also
clogs
up the vacuum tip much more regularly than when I am working on boards
that
are flux-free. Perhaps I'm just a sad old pedant on this sort of thing,
but
it pleases me to look on good workmanship and practices, and I'm far too
long in the tooth to change now ... d;~}

Arfa

he he, you just dont remember the effects now do you!! :-))

xylene and tri-chlorethylene were our favorite whiffers, we used it for god
knows what.

if the alcohol didnt do it, out came that stuff. egads!



"Bill Jeffrey" wrote in message
...
Arfa Daily wrote:
"HapticZ" wrote in message
. net...
"hooch" wrote in message

...
Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.
some newer flux will wash away with water solvent based cleaners

rubbing alcohol is fine too

flux is non-conductive, residue wont affect anything, except if you
constantly obsess about it and gaze affectionately at your work

i mostly just leave it on, just like the asian mass produced junk we
keep
seeing.

aesthetics really dont affect electrical performance!

;-)).


Now you see, I just can't do that ! It's ingrained in me. Many years
ago, I
was taught as an apprentice, to have a tidy mind, and to leave things as
you
found them. My apprentice mentor was one of the best service engineers
that
I ever came across - then or now - and he taught me many things that
have
served me well throughout my professional career in electronic service
work.

One of those things was that the only way anyone should be able to see
where
you've replaced a component on a PCB, is if your soldering is *better*
than
the factory original, and that involves removing flux residue.

There is a practical side to it as well. When flux is left on a board
for
any length of time, something happens to it (so it must still be
reacting in
some way ??) such that it becomes a brilliant resister of a soldering
iron
tip. I repair some commercial boards that used to be done by a company
that
did thoroughly scruffy work, and always left all of the flux on the
board,
from where they had replaced components which regularly fail. When I now
see
these same boards, the rework vacuum iron, really struggles to remelt
the
joints which are covered in flux, against those that are not. It also
clogs
up the vacuum tip much more regularly than when I am working on boards
that
are flux-free. Perhaps I'm just a sad old pedant on this sort of thing,
but
it pleases me to look on good workmanship and practices, and I'm far too
long in the tooth to change now ... d;~}

Arfa

In the old days (late-60's / early 70s for me), we used MEK and a
short-bristled brush (a plumber's acid/flux brush with the bristles cut
down). Yes, we used it indoors, and yes, we used it all day, and no, to
my knowledge no one suffered any effects from it. Every tech and every
engineer had a small pot of it on his bench with a self-closing lid,
which reduced the exposure, and he opened the pot, dipped the brush, and
cleaned each solder joint as he made it. Later, when we started using
small wave-soldered boards, each board was cleaned in the same way after
it came out of the solder bath / trimmer station. It was the only way
that inspection of the board could happen. By the way, this was not
Joe's Garage shop - this was Motorola, and we were inventing/building
the HT-220 Handie-Talkie.

MEK is still available over-the-counter at Sherwin-Williams paint
stores, for example.

Bill

On Nov 29, 5:18 am, "HapticZ" wrote:
"hooch" wrote in message

...

Any suggestions for the best way to remove old flux from circuit
boards when desoldering? The wick soaks up the solder just fine, but
the flux seems to remain behind.

some newer flux will wash away with water solvent based cleaners

rubbing alcohol is fine too

flux is non-conductive, residue wont affect anything, except if you
constantly obsess about it and gaze affectionately at your work

i mostly just leave it on, just like the asian mass produced junk we keep
seeing.

aesthetics really dont affect electrical performance!

True, but sometimes you can't see current paths (and particularly any
breaks in them) properly when they're covered with old flux.

Bill Jeffrey wrote:


MEK is still available over-the-counter at Sherwin-Williams paint
stores, for example.

Hammerite thinners is/was MEK

Ron(UK)

In article
,
wrote:

I prefer MG Chemicals 4140 flux remover in 1 litre bottles. Just
bought 4 more today from MarVac for $16 each. It's a mixture of
alcohols that work better that isopropyl and causes no damage to the
components - including styrenes.

$64/gallon? Hope you don't need too much of it. That's some spendy
juice, there.