|
I have some old solder Flux here that I use for cleaning up oxidized & dirty connections when I replaced components in vintage HP equipment, this Flux has 27% Zinc Chloride, which really helps to wet the connection for soldering. I am wondering how bad is the Zinc Chloride, and what precautions should I take when using it?, maybe someone here has used a similar Flux before,? ? ? ? ? ? ? ? ? ?Brad
|
That is highly corrosive flux intended for plumbing, not electronics. Don't use it on anything electronic, .
On Thu, Oct 17, 2024 at 4:57?AM Brad Latta via <bradley.latta= [email protected]> wrote: I have some old solder Flux here that I use for cleaning up oxidized & dirty connections when I replaced components in vintage HP equipment, this Flux has 27% Zinc Chloride, which really helps to wet the connection for soldering. I am wondering how bad is the Zinc Chloride, and what precautions should I take when using it?, maybe someone here has used a similar Flux before,? ? ? ? ? ? ? ? ? ?Brad
|
It's useful for cleaning badly oxidized soldering iron tips, but don't use it on circuit bits, as Michael T. warned. It will digest your wiring over time.
Cheers,
Tom
--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
420 Via Palou Mall
Stanford University
Stanford, CA 94305-4070
toggle quoted message
Show quoted text
On 10/17/2024 1:56 AM, Brad Latta wrote: I have some old solder Flux here that I use for cleaning up oxidized & dirty connections when I replaced components in vintage HP equipment, this Flux has 27% Zinc Chloride, which really helps to wet the connection for soldering. I am wondering how bad is the Zinc Chloride, and what precautions should I take when using it?, maybe someone here has used a similar Flux before,
|
?
Brad,?
?
I worked at an old time radiator shop repairing old copper/brass radiators
for cars, trucks,
forklifts, 18 wheelers. etc.? We used a zinc chloride based flux to
clean up the dirty, brass
and copper parts for soldering with a solid core 1/8 inch dia. 60/40
solder.? For that purpose,
that flux was necessary.? For electronics, even with flushing the area
with lots of water, corrosion
is at risk of occuring.
?
Bob
?
I have some old solder Flux here that I use for cleaning up oxidized
& dirty connections when I replaced components in vintage HP equipment,
this Flux has 27% Zinc Chloride, which really helps to wet the connection for
soldering. I am wondering how bad is the Zinc Chloride, and what precautions
should I take when using it?, maybe someone here has used a similar Flux
before,?
? ? ? ? ? ? ? ?
?Brad ?
|
Come on guys, it really isn't that bad. The stuff he is talking about is a petroleum jelly based zinc chloride compound. Zinc Chloride is a killed acid. That means that they dissolve enough zinc into HCL that it can take no more, and is neutral pH. It is non-corrosive, and says so in bold red letters right on the can. It was purposefully made for electronics back in the day when everything was point-to-point wiring with components mounted to pins on turrets, or tube sockets. It was also very good for soldering grounds, any old place, on plated steel chasses. I have a bunch of this stuff from when the US government labs banned it... not for corrosion, but rather because they found it was unsuited for high impedance PCB use...no amount of washing with TCE (also banned) would restore the PCB to its like new insulation resistance. I haven't found that to be true... but that is what we were told... It comes in little tin "snuff" cans, and the tin plating inside of the cans stays bright and shiny. I have never seen it do anything to copper other than to remove the copper's patina and brighten it up a bit. All fluxes have to be mildly reactive to copper, or they wouldn't be fluxes. This includes rosin flux. All that said, you shouldn't need zinc chloride solder paste on circuit boards. And you definitely shouldn't use it on high impedance circuits. -Chuck Harris On Thu, 17 Oct 2024 06:51:09 -0400 "Robert Richards" <carboyhat@...> wrote: Brad,
I worked at an old time radiator shop repairing old copper/brass
radiators for cars, trucks,
forklifts, 18 wheelers. etc. We used a zinc chloride based flux to
clean up the dirty, brass
and copper parts for soldering with a solid core 1/8 inch dia. 60/40
solder. For that purpose,
that flux was necessary. For electronics, even with flushing the area
with lots of water, corrosion
is at risk of occuring.
Bob
On Thu, 17 Oct 2024 19:56:54 +1100 "Brad Latta"
<bradley.latta@...> writes:
I have some old solder Flux here that I use for cleaning up oxidized &
dirty connections when I replaced components in vintage HP equipment,
this Flux has 27% Zinc Chloride, which really helps to wet the
connection for soldering. I am wondering how bad is the Zinc
Chloride, and what precautions should I take when using it?, maybe
someone here has used a similar Flux before,
Brad
|
Oh, right, those tin cans with the gooey stuff in them for tinning solder iron tips.? Hmmm, if it allows soldering to steel, I am wondering if it will allow me to solder an Amp BNC connector onto a copper-clad board I'm working on in my garage lab.? The connector might be chrome plated, though.? I flubbed the PCB footprint of the connector, and when I tried to fit it to the board, I had to drill out the holes much larger to get it to fit..? So I need some mechanical support, but the connector body won't solder to the ground plane.? Any ideas?? ?TIA.? ? Jim Ford, Laguna Hills, California, USA?
On Thu, Oct 17, 2024 at 6:10 AM, Chuck Harris <cfharris@...> wrote: Come on guys, it really isn't that bad.? The stuff he is talking about is a petroleum jelly based zinc chloride compound.? Zinc Chloride is a killed acid.? That means that they dissolve enough zinc into HCL that it can take no more, and is neutral pH. It is non-corrosive, and says so in bold red letters right on the can. It was purposefully made for electronics back in the day when everything was point-to-point wiring with components mounted to pins on turrets, or tube sockets.? It was also very good for soldering grounds, any old place, on plated steel chasses. I have a bunch of this stuff from when the US government labs banned it... not for corrosion, but rather because they found it was unsuited for high impedance PCB use...no amount of washing with TCE (also banned) would restore the PCB to its like new insulation resistance.? I haven't found that to be true... but that is what we were told... It comes in little tin "snuff" cans, and the tin plating inside of the cans stays bright and shiny. I have never seen it do anything to copper other than to remove the copper's patina and brighten it up a bit. All fluxes have to be mildly reactive to copper, or they wouldn't be fluxes.? This includes rosin flux. All that said, you shouldn't need zinc chloride solder paste on circuit boards.? And you definitely shouldn't use it on high impedance circuits. -Chuck Harris On Thu, 17 Oct 2024 06:51:09 -0400 "Robert Richards" < carboyhat@...> wrote: > Brad,? > > I worked at an old time radiator shop repairing old copper/brass > radiators for cars, trucks, > forklifts, 18 wheelers. etc.? We used a zinc chloride based flux to > clean up the dirty, brass > and copper parts for soldering with a solid core 1/8 inch dia. 60/40 > solder.? For that purpose, > that flux was necessary.? For electronics, even with flushing the area > with lots of water, corrosion > is at risk of occuring. > > Bob > > On Thu, 17 Oct 2024 19:56:54 +1100 "Brad Latta" > < bradley.latta@...> writes: > I have some old solder Flux here that I use for cleaning up oxidized & > dirty connections when I replaced components in vintage HP equipment, > this Flux has 27% Zinc Chloride, which really helps to wet the > connection for soldering. I am wondering how bad is the Zinc > Chloride, and what precautions should I take when using it?, maybe > someone here has used a similar Flux before, >? ? ? ? ? ? ? ? ? Brad > > > > >
|
I'll never forget the tech hell I was exposed to in my early 20s when I worked for a local repair facility specializing in, among other things, intercom systems in schools and prisons.? The company had one other competitor in the area, and we were constantly having to clean up messes they made on many different PA, intercom, and fire alarm, and nurse call systems all across the state.? It seems that they had a "tech" that worked on their install team who enjoyed using flux designed for plumbing, not electronics, on most of his work.? An inordinate amount of my time was spent sweeping up after that particular elephant.? My "favorite" anecdote was the week I had spent putting in 66 blocks to replace 15-some "Christmas tree" blocks which had terminals literally rusted and rotting away due to Cletus' (the fictitious name we bestowed upon whoever it was at that company that did this) use of that flux a few decades before.? The whole terminal lug would end up rusting through and literally detaching itself from the block.? All that one would see is the end of a wire with a little nub of rust left, dangling in the breeze, without a clue as to where it and it's other identical twins used to be connected.? Thankfully there was usually plenty of slack in the lines fanning out to the facilities, or that could have gone even more sideways quickly.
I couldn't change my career path fast enough after dealing with stuff like this.
|
You should see some of the mess we are cleaning up in VA hospitals, replacing their entire IT infrastructure, data centers, etc at multiple locations.? Their existing IT closets are literally in most cases closets, barely big enough for a two-post rack.? Many have zero cooling whatsoever!? Many have cat 5 and older patch cables piled up (while still in use) against the door two feet deep, the door holding them in when closed!? New standards require Cat 6a cabling and telecom rooms a minimum of 80SF in non-clinical areas.? That's for a single cabinet (replacing all old open racks with enclosed cabinets).? More cabinets, more space.? Old nurse call, analog phone stuff, etc all over the place and out of our scope but still in the way.? The program office in DC wants to eliminate raised floor systems, claiming they cannot cool the equipment and want to see new hot/cold aisle containment with cold air pumped into the aisle between front of rows to flow through.? Even seeing the CFD analysis I am not convinced this is the way to go...
I'll never forget the tech hell I was exposed to in my early 20s when I worked for a local repair facility specializing in, among other things, intercom systems in schools and prisons.? The company had one other competitor in the area, and we were constantly having to clean up messes they made on many different PA, intercom, and fire alarm, and nurse call systems all across the state.? It seems that they had a "tech" that worked on their install team who enjoyed using flux designed for plumbing, not electronics, on most of his work.? An inordinate amount of my time was spent sweeping up after that particular elephant.? My "favorite" anecdote was the week I had spent putting in 66 blocks to replace 15-some "Christmas tree" blocks which had terminals literally rusted and rotting away due to Cletus' (the fictitious name we bestowed upon whoever it was at that company that did this) use of that flux a few decades before.? The whole terminal lug would end up rusting through and literally detaching itself from the block.? All that one would see is the end of a wire with a little nub of rust left, dangling in the breeze, without a clue as to where it and it's other identical twins used to be connected.? Thankfully there was usually plenty of slack in the lines fanning out to the facilities, or that could have gone even more sideways quickly.
I couldn't change my career path fast enough after dealing with stuff like this.
|
I serviced school intercoms for years. The Dukane authorized company was supposedly run by Electrical Engineers. Their designs and installations were pure garbage. One school board's electricians did dangerous repairs, as well. One intercom console used relays instead of the built in switch for all call. The monos used an exposed 120VAC relay, with the terminals exposed. One of the electricians had 'repaired' the control panel by soldering 12 inch writes to a bad electrolytic capacitor and letting an axial capacitor hung into the turntable drawer. It was over 400VDC. The most fun I had was telling a Principal that I had to completely overhaul the system. He was used to the bad work of the deler and electricians so he refused. I told him I had it working temporarily, but I would be back at the end of school on Friday to remove it, and return it on Monday. I cleaned up all the bad repairs, then added a 50 pinn blue ribbon cable? to connect to the classrooms. I had 66 bloks with the connector, so any future repairs would be easy. I had it working 15 minutes after normal morning announcements, because the janitor was 30 minutes late unlocking the building. The principal had apparently told him that I wouldn't show up because he wasn't expecting me.
The dealer expanded the system at my high school. It was RCA. They added two 100W Dukane amps, but couldn't figure out why the audio was severely distorted, so they disconnected them. Those 'engineers' couldn't figure out that the two different amplifiers were 180 degrees out of phasee.
I'll never forget the tech hell I was exposed to in my early 20s when I worked for a local repair facility specializing in, among other things, intercom systems in schools and prisons.? The company had one other competitor in the area, and we were constantly having to clean up messes they made on many different PA, intercom, and fire alarm, and nurse call systems all across the state.? It seems that they had a "tech" that worked on their install team who enjoyed using flux designed for plumbing, not electronics, on most of his work.? An inordinate amount of my time was spent sweeping up after that particular elephant.? My "favorite" anecdote was the week I had spent putting in 66 blocks to replace 15-some "Christmas tree" blocks which had terminals literally rusted and rotting away due to Cletus' (the fictitious name we bestowed upon whoever it was at that company that did this) use of that flux a few decades before.? The whole terminal lug would end up rusting through and literally detaching itself from the block.? All that one would see is the end of a wire with a little nub of rust left, dangling in the breeze, without a clue as to where it and it's other identical twins used to be connected.? Thankfully there was usually plenty of slack in the lines fanning out to the facilities, or that could have gone even more sideways quickly.
I couldn't change my career path fast enough after dealing with stuff like this.
|
On Thursday 17 October 2024 10:34:34 am Nick Andrews wrote: You should see some of the mess we are cleaning up in VA hospitals,
replacing their entire IT infrastructure, data centers, etc at multiple
locations. Their existing IT closets are literally in most cases closets,
barely big enough for a two-post rack. Many have zero cooling whatsoever!
Many have cat 5 and older patch cables piled up (while still in use)
against the door two feet deep, the door holding them in when closed! New
standards require Cat 6a cabling and telecom rooms a minimum of 80SF in
non-clinical areas. That's for a single cabinet (replacing all old open
racks with enclosed cabinets). More cabinets, more space. Old nurse call,
analog phone stuff, etc all over the place and out of our scope but still
in the way. The program office in DC wants to eliminate raised floor
systems, claiming they cannot cool the equipment and want to see new
hot/cold aisle containment with cold air pumped into the aisle between
front of rows to flow through. Even seeing the CFD analysis I am not
convinced this is the way to go... One service call I remember that really sticks in my memory was at a hotel. All sorts of equipment, including phones, computer networking, wifi, and a bunch of other stuff all terminated in one area. Which also happened to be the terminus for their laundry chute! The dust from all those sheets and such got into *everything*, and I'm sure that there was some biohazard there as well. You can probably imagine the overheating problems caused by all of that dust. I had some trouble putting together a recommendation for them to correct this situation, and they sure didn't seem to be inclined to do anything about it, even though I told 'em that there was going to be further trouble with all of this stuff in the not-too-distant future... On Thu, Oct 17, 2024 at 9:21?AM Matt Harris via groups.io <kd4pbs=
[email protected]> wrote:
I'll never forget the tech hell I was exposed to in my early 20s when I
worked for a local repair facility specializing in, among other things,
intercom systems in schools and prisons. The company had one other
competitor in the area, and we were constantly having to clean up messes
they made on many different PA, intercom, and fire alarm, and nurse call
systems all across the state. It seems that they had a "tech" that worked
on their install team who enjoyed using flux designed for plumbing, not
electronics, on most of his work. An inordinate amount of my time was
spent sweeping up after that particular elephant. My "favorite" anecdote
was the week I had spent putting in 66 blocks to replace 15-some "Christmas
tree" blocks which had terminals literally rusted and rotting away due to
Cletus' (the fictitious name we bestowed upon whoever it was at that
company that did this) use of that flux a few decades before. The whole
terminal lug would end up rusting through and literally detaching itself
from the block. All that one would see is the end of a wire with a little
nub of rust left, dangling in the breeze, without a clue as to where it and
it's other identical twins used to be connected. Thankfully there was
usually plenty of slack in the lines fanning out to the facilities, or that
could have gone even more sideways quickly.
I couldn't change my career path fast enough after dealing with stuff like
this. -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life in this section of space, ?a critter that can be killed but can't be tamed. ?--Robert A. Heinlein, "The Puppet Masters" - Information is more dangerous than cannon to a society ruled by lies. --James M Dakin
|
In 1968, the high school I attended was brand new.? The
intercom/building PA was DuKane, a marginal company at best. The
school also had an extremely elaborate language lab system made by
Chester Electronics. That system also allowed the on demand
playing of selected audio tapes in the classrooms through the PA
speakers in the rooms. The interfacing between the systems was a
failure and caused horrific problems. It never worked. With regard
to Zinc chloride fluxes, I have used them to tin old and
improperly stored connectors before installing them.? After
tinning them, I cleaned them off thoroughly with hydrocarbon
solvent to get the wax and petroleum jelly off, followed by a good
scrubbing with hot water and dishwasher detergent and the hottest
rinse possible. I megged them with a 600 volt megger, and had zero
leakage or problems.? I think you could use these fluxes on a
badly corroded epoxy fiberglass circuit board, but not a fibre
one.? The serious cleaning is still needed.? There are paste
fluxes designed for SMD work that are said to be non conductive
and non corrosive, I have used them with great results on boards
and wiring that needs them. I do wash them off? with spray solvent
contact cleaner without lube.
?????? Bruce Gentry, KA2IVY
On 10/17/24 11:07, Michael A. Terrell
wrote:
toggle quoted message
Show quoted text
I serviced school intercoms for years. The Dukane
authorized company was supposedly run by Electrical Engineers.
Their designs and installations were pure garbage.
|
Thanks for all the replys on this topic, I will refrain from using this Flux in future ( except maybe if I have to solder a thick ground wire to a plated chassis maybe! ) ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?Regards Brad?
On Thu, Oct 17, 2024, 20:05 Michael A. Terrell via <terrell.michael.a= [email protected]> wrote: That is highly corrosive flux intended for plumbing, not electronics. Don't use it on anything electronic, .
On Thu, Oct 17, 2024 at 4:57?AM Brad Latta via <bradley.latta= [email protected]> wrote: I have some old solder Flux here that I use for cleaning up oxidized & dirty connections when I replaced components in vintage HP equipment, this Flux has 27% Zinc Chloride, which really helps to wet the connection for soldering. I am wondering how bad is the Zinc Chloride, and what precautions should I take when using it?, maybe someone here has used a similar Flux before,? ? ? ? ? ? ? ? ? ?Brad
|
Chuck said:
"Come on guys, it really isn't that bad. ?The stuff he?
is talking about is a petroleum jelly based zinc chloride
compound. ?Zinc Chloride is a killed acid. ?That means that
they dissolve enough zinc into HCL that it can take no more,
and is neutral pH.
It is non-corrosive, and says so in bold red letters right?
on the can."
Not according to who say "It is corrosive to metals"
The key is in the "chloride". I don't know how you determined the OP had a jelly based flux as he didn't say.
Not all flux is corrosive. Rosin flux is not. It does not have to be it works by excluding air (oxygen) from the hot joint.
A solution fod zinc hloride is acidic with a PH of about 4. It is not suitable for electrical applications.
?
Robert.
|
RMA flux is mildly activated rosin. If you need something stronger, the components are damaged. I have only used acid flux to solder brass or steel pieces together to make a chassis or shielding, then wire brushed it and reflowed it with rosin flux. I use a solder pot to pretin most connectors. I moved and rebuilt a 1952 RCA TV transmitter, a couple decades ago. I used silver solder for the cooling system. I tinned the pipe and fittings, wiping away the excess solder. Then I suded rosin cored solder , because the cooling system had 7KV across it. It? required 100 Megohm per cubic centimeter purity in the coolant. The slightest bit of acid flux would contaminate hundreds of gallons of distilled water & antifreeze. Pre tinned pipe and fittings were a breeze to solder, with a torch. it wicked all the way inside, then formed a smooth bead all around the exterior. without trying since the flux didn't have to carry off any oxides, It also meant that there were no leaks. Some previous 'plumber/engineer had brazed over the leaks form their bad solder job. The fittings were custom made and NLA, so I had to saw off the old copper pipe , then heat it as I pried the old pipe loose , then work it back & forth until the brazing broke. That was followed by carefully filing away just the burs, before reassembly. It was a lot of extra work, caused by someone who couldn't do decent soldering. BTW, it only had two semiconductors. Tey were in customized Bird 43 wattmeter to read the drive level to the final tubes.
On Thu, Oct 17, 2024 at 4:40?PM Robert G8RPI via <robert8rpi= [email protected]> wrote: Chuck said:
"Come on guys, it really isn't that bad.? The stuff he?
is talking about is a petroleum jelly based zinc chloride
compound.? Zinc Chloride is a killed acid.? That means that
they dissolve enough zinc into HCL that it can take no more,
and is neutral pH.
It is non-corrosive, and says so in bold red letters right?
on the can."
Not according to who say "It is corrosive to metals"
The key is in the "chloride". I don't know how you determined the OP had a jelly based flux as he didn't say.
Not all flux is corrosive. Rosin flux is not. It does not have to be it works by excluding air (oxygen) from the hot joint.
A solution fod zinc hloride is acidic with a PH of about 4. It is not suitable for electrical applications.
?
Robert.
|
Ok, let's talk about this. It is true that the OP didn't mention whether he was using a paste, or a liquid... just that what he was using had 27% ZnCl. If the other 73% is water, that would cause problems all of its own... If it is 73% something else, perhaps not. The pubchem listing you brought into this conversation must be for an aqueous solution of ZnCl and water, or pH would be undefined. [pH == -log10(H+), or 14 - log10(OH-)] It should be obvious that ZnCl has no water, just as the NaCl in the shaker in your kitchen has no water. A liquid solution of ZnCl in water would be very difficult to handle in an electronic application. it would run everywhere leading to the anecdotes that sprung up like mushrooms on the mention of ZnCl as a flux... About the only way liquid ZnCl flux could be used in electronics work is dipping a lead in it before soldering. Liquid ZnCl flux is mostly water and HCl, so it is bad to even have around electronics equipment. I inferred by the OP's use case, that he was talking about the old fashioned ZnCl solder paste concoction that has been used for decades in the assembly of point-to-point soldered electronic equipment. At this point in the conversation only he knows which of us made the correct guess. ZnCl is a compound that is neither an acid, nor a base. It is neutral. ZnCl in water is far more interesting. It is also neither an acid, nor a base. It is an ionic solution of Zn+, Cl-, H+ and OH- ions all in a perfect balance. That said, it is impossible to say which +ions of the ionic solution are "coupled" with which -ions, so a ZnCl solution is at the same time comprised of: H+ Cl-, Zn+ OH-, and H+ OH- It looks as much like hydrochloric acid (a strong acid), as it does like ZnCl (a neutral salt), as it does like zinc hydroxide (a strong base). The typical liquid ZnCl flux is not "killed". It is left a little spicy by not completely neutralizing the HCl with ZnOH. It is a ZnCl/HCl solution. Rosin flux: Rosin flux that is not activated, will do nothing to help in soldering a joint made up of slightly oxidized copper pieces. The solder will ball up, never wetting the copper. It may help in soldering a joint with clean metals, as it will keep the oxygen in the air from reacting with the hot copper. To make such a joint, you would have to either freshly sand the oxide off of the copper, or apply a scrubbing action (to break up the oxides) with your soldering iron tip. To make soldering a little easier, manufacturers "activate" the rosin to various degrees. Activation is another word for adding acid. The acid combines with the oxide, puts it into solution, where it floats to the surface of the joint and sits relatively harmlessly until moisture from the air gets involved. Just as the ZnCl in solder paste does. -Chuck Harris On Thu, 17 Oct 2024 13:40:47 -0700 "Robert G8RPI via groups.io" <robert8rpi@...> wrote: Chuck said:
"Come on guys, it really isn't that bad. ?The stuff he
is talking about is a petroleum jelly based zinc chloride
compound. ?Zinc Chloride is a killed acid. ?That means that
they dissolve enough zinc into HCL that it can take no more,
and is neutral pH.
It is non-corrosive, and says so in bold red letters right
on the can."
Not according to
who say "It
is corrosive to metals" The key is in the "chloride". I don't know
how you determined the OP had a jelly based flux as he didn't say.
Not all flux is corrosive. Rosin flux is not. It does not have to be
it works by excluding air (oxygen) from the hot joint. A solution fod
zinc hloride is acidic with a PH of about 4. It is not suitable for
electrical applications.
Robert.
|
Thanks, Chuck.? I've forgotten much of my chemistry since I switched majors from biochemistry to EE about 40 years ago.? IIRC, fluxes come in several classes, R for pure rosin - not activated, RMA for rosin mildly activated - a small amount of acid added, and RA for rosin activated - a relatively large amount of acid added.? Then there's the "acid" flux - no rosin at all, and as people have said, suitable for plumbing and not for electronics.? I had heard years ago that Hughes Aircraft (since split into Raytheon where I work and Boeing) was using lemon juice instead of rosin flux, but I haven't tried that.? ? ? ? Jim
On Fri, Oct 18, 2024 at 5:40 AM, Chuck Harris <cfharris@...> wrote: Ok, let's talk about this.
It is true that the OP didn't mention whether he was using
a paste, or a liquid... just that what he was using had 27%
ZnCl.? If the other 73% is water, that would cause problems
all of its own... If it is 73% something else, perhaps not.
The pubchem listing you brought into this conversation must
be for an aqueous solution of ZnCl and water, or pH would
be undefined.
[pH == -log10(H+), or 14 - log10(OH-)]
It should be obvious that ZnCl has no water, just as the
NaCl in the shaker in your kitchen has no water.
A liquid solution of ZnCl in water would be very difficult
to handle in an electronic application. it would run
everywhere leading to the anecdotes that sprung up like
mushrooms on the mention of ZnCl as a flux...
About the only way liquid ZnCl flux could be used in
electronics work is dipping a lead in it before soldering.
Liquid ZnCl flux is mostly water and HCl, so it is bad
to even have around electronics equipment.
I inferred by the OP's use case, that he was talking
about the old fashioned ZnCl solder paste concoction
that has been used for decades in the assembly of
point-to-point soldered electronic equipment.
At this point in the conversation only he knows which of
us made the correct guess.
ZnCl is a compound that is neither an acid, nor a base.
It is neutral.? ZnCl in water is far more interesting.
It is also neither an acid, nor a base.? It is an ionic
solution of Zn+, Cl-, H+ and OH- ions all in a perfect
balance.
That said, it is impossible to say which +ions of the
ionic solution are "coupled" with which -ions, so a ZnCl
solution is at the same time comprised of:
H+ Cl-, Zn+ OH-, and H+ OH-
It looks as much like hydrochloric acid (a strong acid),
as it does like ZnCl (a neutral salt), as it does like
zinc hydroxide (a strong base).
The typical liquid ZnCl flux is not "killed".? It is left
a little spicy by not completely neutralizing the HCl with
ZnOH.
It is a ZnCl/HCl solution.
Rosin flux:
Rosin flux that is not activated, will do nothing to help
in soldering a joint made up of slightly oxidized copper
pieces.? The solder will ball up, never wetting the copper.
It may help in soldering a joint with clean metals, as it
will keep the oxygen in the air from reacting with the
hot copper.
To make such a joint, you would have to either freshly
sand the oxide off of the copper, or apply a scrubbing
action (to break up the oxides) with your soldering iron
tip.
To make soldering a little easier, manufacturers "activate"
the rosin to various degrees.? Activation is another word
for adding acid.? The acid combines with the oxide, puts
it into solution, where it floats to the surface of the
joint and sits relatively harmlessly until moisture from
the air gets involved.? Just as the ZnCl in solder paste
does.
-Chuck Harris
On Thu, 17 Oct 2024 13:40:47 -0700 "Robert G8RPI via groups.io"
<robert8rpi@...> wrote:
> Chuck said:
> "Come on guys, it really isn't that bad. ?The stuff he
> is talking about is a petroleum jelly based zinc chloride
> compound. ?Zinc Chloride is a killed acid. ?That means that
> they dissolve enough zinc into HCL that it can take no more,
> and is neutral pH.
> It is non-corrosive, and says so in bold red letters right
> on the can."
>
> Not according to
> who say "It
> is corrosive to metals" The key is in the "chloride". I don't know
> how you determined the OP had a jelly based flux as he didn't say.
> Not all flux is corrosive. Rosin flux is not. It does not have to be
> it works by excluding air (oxygen) from the hot joint. A solution fod
> zinc hloride is acidic with a PH of about 4. It is not suitable for
> electrical applications.
>
> Robert.
>
>
>
>
>
|
On Fri, Oct 18, 2024 at 05:40 AM, Chuck Harris wrote:
ZnCl in water is far more interesting.
It is also neither an acid, nor a base. It is an ionic
solution of Zn+, Cl-, H+ and OH- ions all in a perfect
balance.
I was following the thread...AFAIK...
Zinc chloride is an odorless white powder.
It is extremely soluble in water
It also readily absorbs atmospheric moisture... to crystallize and clump... so, we used to keep it in a desiccator.
It can also absorb enough water to form a liquid.
Zinc chloride also dissolves in ?ethanol, acetone, and glycerol.
?
The damp crystals, or liquefied crystals, are/is very corrosive, having a pH of approximately 1 to 4, so acidic.
A water solution of zinc chloride is also acidic... the acidity depending on the concentration.
It does not form a very acidic solution with ethanol, acetone, or glycerol.
?
Zinc chloride is a Lewis acid.
In a water solution, the Zn ions undergo hydrolysis... that produces hydrogen ions... and that's responsible for the acidity.
?
The zinc chloride in a carbon zinc battery... part of the electrolyte paste... it is not very acidic
When the battery leaks and the zinc chloride absorbs moisture... then your favorite Lewis acid does it's thing.
?
If you have zinc chloride crystals... or powder... on or around, steel, iron, or copper... corrosion will eventually happen.
?
After using a flux, having zinc chloride, you might see traces of white powder.
If it's zinc chloride then washing with water can dissolve it.
Some zinc chloride may remain... because the 'flux' sometimes possesses 'gooey' stuff ... and often that 'gooey' stuff doesn't like to wash away with water.
?
?
ChatGPT said:
?
?
?
?
?
?
?
?
?
?
|
On Fri, Oct 18, 2024 at 06:26 AM, Jim Ford wrote:
R for pure rosin - not activated
AFAIK... rosin for flux... like that from Slash Pine tapping (in the U.S.) contains about 50% abietic acid.
That's a weak organic acid.
At room temperature... it's a solid pale yellow compound, that has that pine smell.
?
You can take 'pure' rosin and dissolve it in alcohol... to make a rosin flux... of various viscosity.
It does 'help' remove oxidation from copper.
You can see that if you 'pool' some on... and then put the tip of the iron in. (The copper will become brighter.)
?
IMO... I don't think anyone really knows what a flux 'activator' is. (Soldering is a lot easier to 'do' than to 'understand')
But here's a list.? (some are used in 'hard' soldering)
Acidic Activators
Common Activators for Rosin Flux
Zinc Chloride (ZnCl?) ? ??
Hydrochloric Acid (HCl)
Ammonium Chloride (NH?Cl)
Sodium Chloride (NaCl)
Potassium Chloride (KCl)
Organic Acids
Tartaric Acid ? ? ?
Glycolic Acid
Sodium Bicarbonate (NaHCO?)
Boric Acid (H?BO?)
Basic? Activators? ?
Amines
Ethanolamine
Diethanolamine
Triethanolamine
?
|
On Thu, Oct 17, 2024 at 06:55 PM, Michael A. Terrell wrote:
I moved and rebuilt a 1952 RCA TV transmitter, a couple decades ago.
Michael... did you ever have to work on a Pye TVT UHF transmitter?? I'm sure they were a bit easier across the pond in the UK, but over here, they were not only their usual deadly, with non-interlocked 35KV places accessible with the removal of only a few screws, but to work on the steam condensers or anything else in the cooling circuit for the klystrons, one had to source metric copper pipe hardware.? Surely a walk in the park in it's motherland, but not so much here in the states.
I took great pleasure in ventilating parts of that transmitter with a .357 magnum revolver when we decommissioned that one.
|
No. I've only wrked on Comark, Gates and RCA TV transmitters, butt I received the salvage of a 5KW Channel 8 NTSC tranmitter from Vietnam, after it was shot up by the enemy, and the engineers were killed I had a similar transmitter at Ft Greely. but it didn't have the two amplifer cabinets. That Aural fiinal would have been great for a Two Meter repeater! The RCA used water cooled power tetrodes that were designed for just the TTU-265 series of UHF ransmitters.?
RCA was safety conscious, and there were many interlock switches in that transmitter. Gates and Comark had them as well, but the RCA was seven, four foot square custom aluminum cabinets and those switches could be knocked out of alignment, causing intermittent shutdowns. TIt was one of the first 'High Power UHF transmitters in the US. Ours was licensed for 1.3 MW EIRP, The Comark was 5 MW EIRP, but thee gates were low power.80 + 500Watts each. The FCC license was interesting. It stated 500 Watts, oer as deemed necessary, and the expiration date was, Until no longer needed. Ft Greely also had a Cates BC250 AM transmitter with a similar license. I was the only engineer on that base, and the stations were cra when I arrived BTW, have you ever seen a broadcast station using a center tapped dipole, instead of a tower? It was the only one I ever saw! I think it was onn 980 KHz, but I left there over 50 years ago.
On Thu, Oct 17, 2024 at 06:55 PM, Michael A. Terrell wrote:
I moved and rebuilt a 1952 RCA TV transmitter, a couple decades ago.
Michael... did you ever have to work on a Pye TVT UHF transmitter?? I'm sure they were a bit easier across the pond in the UK, but over here, they were not only their usual deadly, with non-interlocked 35KV places accessible with the removal of only a few screws, but to work on the steam condensers or anything else in the cooling circuit for the klystrons, one had to source metric copper pipe hardware.? Surely a walk in the park in it's motherland, but not so much here in the states.
I took great pleasure in ventilating parts of that transmitter with a .357 magnum revolver when we decommissioned that one.
|
Michael A. Terrell
Nick Andrews