Soldering newbie

[M. Hamed]

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge? I have been using it recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge.. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.


I know this has been answered a million times before but if someone is feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.

 

[Tim Wescott]

On Tue, 02 Apr 2013 16:04:14 -0700, M. Hamed wrote:

I am not new to soldering. I have some soldering experience. I have
built a radio kit with no soldering problems whatsoever. I have made
little boards for things like transistor amplifiers for my crystal
radio. I have little surface mount experience, but in a moment of
extreme courage, my boss let me rework about 50 PCBs at once when he was
on vacation. That involved soldering a little SMT cap using tiny little
wire to a nearby IC pin. Most of the boards worked, but the job looked
horribly ugly.

The reason I consider myself still a newbie, is that successes are not
always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't
click. I thought I could start this thread to ask questions that will
probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron
with fresh solder before starting on a joint. Every time I do this the
solder burns and discolors. Is that normal or am I doing something
wrong? Do I have to be really fast before solder burns?

Discolors how? If it turns brown it's not the solder -- it's the flux.
If it turns gray, then the solder is oxidizing. The flux getting a bit
brown isn't that bad, but either one of these things happening is an
indication of your iron being too hot. You probably can't get away from
this easily without using a temperature-controlled iron.

If you have tip cleaner or a damp sponge that'll work well, too. The tip
needs to be tinned, but more importantly it needs to be clean.

(Don't use a temperature controlled iron unless you already own it, or
have long-term access. They're instantly addictive. It'll be like the
first time someone took the butter knife out of your hand and gave you a
real screwdriver -- you won't want to go back).

2) Soldering guides tell you to always heat the joint not the solder.
Whenever I do this, it seems it takes forever for solder to melt. It
also seems that the pointy part of the tip (as they always show in
drawings) isn't really hot enough I have to find a sweet spot on the tip
that is hot enough and then touch it to the wire. Do I just have a bad
iron?

It could be. But it could just be that the tip isn't clean, or isn't
tinned enough. Dirt, oxidized solder, and burnt flux don't transmit heat
well.

What you're really trying to do is to make sure that the whole joint is
hot enough to melt solder -- you can do a perfectly good solder joint by
dribbling solder on it, then reheating everything. But unless you're
really good, you can't tell the difference between a good joint done this
way and a poor joint done this way. Melting the solder onto the metal to
be soldered is a 100% reliable way of making sure it's at soldering
temperature.

3) Can I use copper wool instead of a wet sponge? I have been using it
recently with success. The problem is that I'm not sure if it's better
than a sponge or not. I'm not even sure of the function of the copper or
the sponge. I know it's for wiping the tip clean but it's hard for me to
gauge how much better cleaning the tip actually provides.

If the tip is clean, you've done a good job. I haven't used copper wool
much (mostly when someone shoved a soldering iron under my nose). All of
the people that I know who solder Really Well use a sponge.

They (and I) use a _damp_ sponge -- if it's dripping, it's way too wet:
it'll freeze the solder on the tip and stick the gunk on solid.

4) When to use flux and when is it not important? I soldered the
transistor radio kit completely without flux. But also the type of
solder they provided with the kit seemed really good, I thought may be
the solder has it all.

Electronic solder comes with flux built in -- the solder is actually a
hollow tube filled with flux (or, sometimes, a tube with more than one
hole, all filled with flux).

If you've been using anything other than flux intended for electronics
then you've been using the Wrong Stuff. Flux for electronics (usually
called "rosin flux") is very mild, and the stuff you're expected to
solder is easy to solder to. Flux for mechanical assemblies ("acid
flux") is much more harsh -- which is what you want when you need to
solder to steel or other difficult materials, but it causes corrosion if
it's not cleaned all the way off of your job, and it's almost impossible
to clean electronics 100%.

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

 

[John Larkin]

On Tue, 2 Apr 2013 16:04:14 -0700 (PDT), "M. Hamed"
<mhdpublic@gmail.com> wrote:

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Your iron is too hot. You need one of the temperature-controlled ones.
Metcal are the best.

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

I poke the tip into the intersection of the board and the part, and
apply solder to the 3-way intersection. That wets everything and
transfers a bunch of heat fast.

3) Can I use copper wool instead of a wet sponge? I have been using it recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

It's to remove excess solder and burnt, crusty old flux. Sponge works.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

Usually the flux in rosin-core electronic solder is all you need. I
rarely add additional liquid flux.



--

John Larkin Highland Technology, Inc

jlarkin at highlandtechnology dot com
http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom laser drivers and controllers
Photonics and fiberoptic TTL data links
VME thermocouple, LVDT, synchro acquisition and simulation

 

[Rich Webb]

On Tue, 02 Apr 2013 17:29:07 -0700, John Larkin
<jlarkin@highlandtechnology.com> wrote:

On Tue, 2 Apr 2013 16:04:14 -0700 (PDT), "M. Hamed"
mhdpublic@gmail.com> wrote:

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

Your iron is too hot. You need one of the temperature-controlled ones.
Metcal are the best.

Oy! You'll give the poor guy a heart attack.

Once the OP has started breathing again, he might want to look for
something like <http://www.howardelectronics.com/xytronic/lf369D.html>
It's not a knock-off brand and is reasonably inexpensive (as these
things go). Some (of many more) alternates are over at
<http://www.circuitspecialists.com/soldering-stations> where they have
house-branded stations. Haven't tried these but I've purchased other
stuff from them in the past w/o complaints.

 

[Phil Allison]

"M. Hamed"


1) Soldering guides always recommend you to tin the tip of your iron with
fresh solder before starting on a joint. Every time I do this the solder
burns and discolors.

** The iron is too hot, get an adjustable or temp controlled one.

It is possible to use a light dimmer with a cheap iron to reduce the temp.


2) Soldering guides tell you to always heat the joint not the solder.
Whenever I do this, it seems it takes forever for solder to melt.

** When you touch the tip against a joint, immediately apply a little solder
to tip so the hot solder carries the heat around.

It also seems that the pointy part of the tip (as they always show in
drawings) isn't really hot enough I have to find a sweet spot on the tip
that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge?

** Brass wool is best.


4) When to use flux and when is it not important? I soldered the transistor
radio kit completely without flux. But also the type of solder they provided
with the kit seemed really good, I thought may be the solder has it all.


** Use only flux cored, 60:40 tin lead solder for electronics.

Avoid the lead free kind.



.... Phil

 

[Michael Black]

On Tue, 2 Apr 2013, M. Hamed wrote:

I am not new to soldering. I have some soldering experience. I have
built a radio kit with no soldering problems whatsoever. I have made
little boards for things like transistor amplifiers for my crystal
radio. I have little surface mount experience, but in a moment of
extreme courage, my boss let me rework about 50 PCBs at once when he was
on vacation. That involved soldering a little SMT cap using tiny little
wire to a nearby IC pin. Most of the boards worked, but the job looked
horribly ugly.

The reason I consider myself still a newbie, is that successes are not
always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't
click. I thought I could start this thread to ask questions that will
probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron
with fresh solder before starting on a joint. Every time I do this the
solder burns and discolors. Is that normal or am I doing something
wrong? Do I have to be really fast before solder burns?

If the iron wasn't tinned right at the beginning, then the tip gains some

coating that causes the solder to just roll off.

I have a vague memory of this happening once, but I can't remember what I
did. I do know that when you have properly tinned the tip from the
beginning, some residue can build up, and you need to work at clearing
that up so the solder doesn't ball and roll off when heated, but spreads
out over the tip.

I also have a vague memory of burning solder on one iron, yet it seems
more related to an untinned tip. Because it's not like I've bought
endless packs of solder over the years, and the same solder works fine on
my soldering gun, which is much hotter than the irons I've had in forty
years. I think maybe I ended up with some bad solder, or solder rated at
a lower temperature. But it's been decades.

2) Soldering guides tell you to always heat the joint not the solder.
Whenever I do this, it seems it takes forever for solder to melt. It
also seems that the pointy part of the tip (as they always show in
drawings) isn't really hot enough I have to find a sweet spot on the tip
that is hot enough and then touch it to the wire. Do I just have a bad
iron?

The guides all say that, but most people do melt some solder on the tip as

it is held against the joint. The melted solder helps the heat to flow.
Once there is a bit of solder on the joint, the heat flows more easily.

3) Can I use copper wool instead of a wet sponge? I have been using it
recently with success. The problem is that I'm not sure if it's better
than a sponge or not. I'm not even sure of the function of the copper or
the sponge. I know it's for wiping the tip clean but it's hard for me to
gauge how much better cleaning the tip actually provides.

No. Except really cheap irons (the tips will last a very short time),

soldering iron tips have been plated for decades. If you use something
metallic to clean it, you may clear off the plating. The plating is a
great thing, it protects the tip. Without it, the tip will decay after a
relatively short time, while all the plated tips I've had last forever.

You don't want a lot of solder on a tip, at least when you are soldering,
yet keeping some solder on the tip protects it. So you pull your iron out
of the stand, briefly wipe it on the sponge (paper towels work too, I
don't even bother dampening them) before you solder, and then before you
put the iron back in the stand (at least if it will be sitting there for a
while), add a bit more solder.

So it's primarily to get the excess solder off, something you don't need
steel or copper wool for.

There are times when there's sort of a carbon buildup, I guess solder left
on the tip too long without being wiped off, and that takes some work to
clear off, but no actual filing or need for steel wool. But the build up
happens because the excess solder isn't regularly wiped off.

That said, again if you don't tin the tip properly at the start, there
will be later problems.

4) When to use flux and when is it not important? I soldered the
transistor radio kit completely without flux. But also the type of
solder they provided with the kit seemed really good, I thought may be
the solder has it all.

The solder has flux built in. Melting a bit of solder on the tip of the

iron helps to spread the flux onto the joint you are trying to solder.
Same thing happens with old solder, the flux has long gone, you try really
hard to heat up the joint but no success. Melt a bit of solder against
the iron on the joint, and the new solder provides flux for the heat to
flow, so the old solder melts like it should.


Michael

I know this has been answered a million times before but if someone is
feeling bored may be they can share their experience. I know I probably
can spend hours scouring internet forums and getting all sorts of
conflicting information. I thought I may get some direct answers here!
THANKS.

 

[Phil Allison]

"Bill Bowden"

Another trick is to coat both surfaces with solder before joining them
together and clean the surface of the leads. So, if you want to solder
two resistor leads together, use an exacto knife to scrape the
resistor leads clean ...

** You should never have to do that.

Only very old and badly corroded leads require scraping.


..... Phil

 

[Phil Allison]

"M. Hamed"

I know this has been answered a million times before but if someone is
feeling bored may be they can share their experience. I know I probably can
spend hours scouring internet forums and getting all sorts of conflicting
information. I thought I may get some direct answers here!


** There are two common reasons why beginners have problems soldering:

1. They are using a shit awful soldering iron.

2. They are using lead free or flux free solder.

Hamed, like most, has not revealed what HE is using.



..... Phil

 

[Bill Bowden]

On Apr 2, 3:04 pm, "M. Hamed" <mhdpub...@gmail.com> wrote:

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge? I have been using it recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

I know this has been answered a million times before but if someone is feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.

Another trick is to coat both surfaces with solder before joining them
together and clean the surface of the leads. So, if you want to solder
two resistor leads together, use an exacto knife to scrape the
resistor leads clean and then apply a thin coat of solder to each
lead. Then put the resistor leads together and solder the joint. You
may not need any solder on the iron, just heat the leads and they will
melt together..

-BIll

 

[notbob]

On 2013-04-03, Rich Webb <webb.ra@example.net> wrote:

On Tue, 02 Apr 2013 17:29:07 -0700, John Larkin

Metcal are the best.

Oy! You'll give the poor guy a heart attack.

No kidding. Metcals are insanely overpriced, even if they now have a
station in the mid $200 range. Jes get a Hakko FX888. You can get
'em fer < $85 and they have a great range of tips, even down into SMT
sizes.

nb

 

[Phil Hobbs]

On 4/2/2013 11:29 PM, Bill Bowden wrote:

On Apr 2, 3:04 pm, "M. Hamed" <mhdpub...@gmail.com> wrote:

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge? I have been using it recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

I know this has been answered a million times before but if someone is feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.


Another trick is to coat both surfaces with solder before joining them
together and clean the surface of the leads. So, if you want to solder
two resistor leads together, use an exacto knife to scrape the
resistor leads clean and then apply a thin coat of solder to each
lead. Then put the resistor leads together and solder the joint. You
may not need any solder on the iron, just heat the leads and they will
melt together..

-BIll

If the leads are oxidized like that, switching to RA-flux solder will
improve your life. I have a bunch of old parts that I still use, and RA
is the bomb.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[John Larkin]

On Wed, 03 Apr 2013 11:16:37 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 4/2/2013 11:29 PM, Bill Bowden wrote:
On Apr 2, 3:04 pm, "M. Hamed" <mhdpub...@gmail.com> wrote:

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge? I have been using it recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

I know this has been answered a million times before but if someone is feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.


Another trick is to coat both surfaces with solder before joining them
together and clean the surface of the leads. So, if you want to solder
two resistor leads together, use an exacto knife to scrape the
resistor leads clean and then apply a thin coat of solder to each
lead. Then put the resistor leads together and solder the joint. You
may not need any solder on the iron, just heat the leads and they will
melt together..

-BIll


If the leads are oxidized like that, switching to RA-flux solder will
improve your life. I have a bunch of old parts that I still use, and RA
is the bomb.

Cheers

Phil Hobbs

Is there a downside to RA? Is it corrosive or conductive or anything? We use
RMA, not sure why. RMA does not seem to be conductive, at the 1e14 ohm level,
even at high humidity.


--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Phil Hobbs]

On 4/3/2013 11:26 AM, John Larkin wrote:

On Wed, 03 Apr 2013 11:16:37 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 4/2/2013 11:29 PM, Bill Bowden wrote:
On Apr 2, 3:04 pm, "M. Hamed" <mhdpub...@gmail.com> wrote:

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge? I have been using it recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

I know this has been answered a million times before but if someone is feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.


Another trick is to coat both surfaces with solder before joining them
together and clean the surface of the leads. So, if you want to solder
two resistor leads together, use an exacto knife to scrape the
resistor leads clean and then apply a thin coat of solder to each
lead. Then put the resistor leads together and solder the joint. You
may not need any solder on the iron, just heat the leads and they will
melt together..

-BIll


If the leads are oxidized like that, switching to RA-flux solder will
improve your life. I have a bunch of old parts that I still use, and RA
is the bomb.

Cheers

Phil Hobbs

Is there a downside to RA? Is it corrosive or conductive or anything? We use
RMA, not sure why. RMA does not seem to be conductive, at the 1e14 ohm level,
even at high humidity.


I think it's more acidic than RMA, so it may be more corrosive and/or

leakier, I'm not entirely sure. It really makes dead bugging easier though.

Speaking of prototyping, those Bellin Systems breakout boards have a
crappy solder mask--it doesn't go between pins on 0.025" or 0.5 mm pitch
parts. I may switch to Schmartboards, even though they're much more
expensive

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510 USA
+1 845 480 2058

hobbs at electrooptical dot net
http://electrooptical.net

 

[John Larkin]

On Wed, 03 Apr 2013 11:32:40 -0400, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

On 4/3/2013 11:26 AM, John Larkin wrote:
On Wed, 03 Apr 2013 11:16:37 -0400, Phil Hobbs
pcdhSpamMeSenseless@electrooptical.net> wrote:

On 4/2/2013 11:29 PM, Bill Bowden wrote:
On Apr 2, 3:04 pm, "M. Hamed" <mhdpub...@gmail.com> wrote:

I am not new to soldering. I have some soldering experience. I have built a radio kit with no soldering problems whatsoever. I have made little boards for things like transistor amplifiers for my crystal radio. I have little surface mount experience, but in a moment of extreme courage, my boss let me rework about 50 PCBs at once when he was on vacation. That involved soldering a little SMT cap using tiny little wire to a nearby IC pin. Most of the boards worked, but the job looked horribly ugly.

The reason I consider myself still a newbie, is that successes are not always repeatable, and failures are not always avoidable.

I have read numerous guides on the Internet but some things really don't click. I thought I could start this thread to ask questions that will probably be obvious to some but still not very clear to me.

The questions at hand for now are these:

1) Soldering guides always recommend you to tin the tip of your iron with fresh solder before starting on a joint. Every time I do this the solder burns and discolors. Is that normal or am I doing something wrong? Do I have to be really fast before solder burns?

2) Soldering guides tell you to always heat the joint not the solder. Whenever I do this, it seems it takes forever for solder to melt. It also seems that the pointy part of the tip (as they always show in drawings) isn't really hot enough I have to find a sweet spot on the tip that is hot enough and then touch it to the wire. Do I just have a bad iron?

3) Can I use copper wool instead of a wet sponge? I have been using it recently with success. The problem is that I'm not sure if it's better than a sponge or not. I'm not even sure of the function of the copper or the sponge. I know it's for wiping the tip clean but it's hard for me to gauge how much better cleaning the tip actually provides.

4) When to use flux and when is it not important? I soldered the transistor radio kit completely without flux. But also the type of solder they provided with the kit seemed really good, I thought may be the solder has it all.

I know this has been answered a million times before but if someone is feeling bored may be they can share their experience. I know I probably can spend hours scouring internet forums and getting all sorts of conflicting information. I thought I may get some direct answers here! THANKS.


Another trick is to coat both surfaces with solder before joining them
together and clean the surface of the leads. So, if you want to solder
two resistor leads together, use an exacto knife to scrape the
resistor leads clean and then apply a thin coat of solder to each
lead. Then put the resistor leads together and solder the joint. You
may not need any solder on the iron, just heat the leads and they will
melt together..

-BIll


If the leads are oxidized like that, switching to RA-flux solder will
improve your life. I have a bunch of old parts that I still use, and RA
is the bomb.

Cheers

Phil Hobbs

Is there a downside to RA? Is it corrosive or conductive or anything? We use
RMA, not sure why. RMA does not seem to be conductive, at the 1e14 ohm level,
even at high humidity.


I think it's more acidic than RMA, so it may be more corrosive and/or
leakier, I'm not entirely sure. It really makes dead bugging easier though.

Speaking of prototyping, those Bellin Systems breakout boards have a
crappy solder mask--it doesn't go between pins on 0.025" or 0.5 mm pitch
parts. I may switch to Schmartboards, even though they're much more
expensive

Cheers

Phil Hobbs

I love the Bellins... just bought a few more sheets. Each adapter winds up
costing around 30 cents, about 1/10 of some others. I hadn't noticed any
difficulty soldering, but I mostly use SOT23 and SO8 sorts of packages, not any
big fine-pitch parts. Once you get to stuff like uPs and ADCs and things, it
makes sense to lay out a real PC board.

We accumulate a list of cool circuits, adapters, crazy ideas, whatever, and when
we need to prototype a nontrivial circuit, we toss those extras around it and
lay out a board, usually 4-layer, and buy 10 of them. We lay things out so you
can shear or saw things apart. Here's the latest one:

https://dl.dropbox.com/u/53724080/PCBs/Z312.JPG


We included the RJ45 to SMA breakout because we couldn't find one anywhere!



--

John Larkin Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

 

[Rich Webb]

On Wed, 3 Apr 2013 12:38:54 -0700 (PDT), "M. Hamed"
<mhdpublic@gmail.com> wrote:

Thanks for all the help.

On Tuesday, April 2, 2013 4:50:39 PM UTC-7, Tim Wescott wrote:
Discolors how? If it turns brown it's not the solder -- it's the flux.
If it turns gray, then the solder is oxidizing. The flux getting a bit
brown isn't that bad, but either one of these things happening is an
indication of your iron being too hot. You probably can't get away from
this easily without using a temperature-controlled iron.


Yes, it is brownish with some blue. You're right it's most likely the flux.
I do have a temperature controlled station. I looked last night at the temperature setting and it was about 750-800.


If you have tip cleaner or a damp sponge that'll work well, too. The tip
needs to be tinned, but more importantly it needs to be clean.

So do I need to clean every time before applying solder?

They (and I) use a _damp_ sponge -- if it's dripping, it's way too wet:
it'll freeze the solder on the tip and stick the gunk on solid.


Yes, I am realizing now my sponge had too much water. I tried the scotch bright cleaning sponges but I didn't know they had extra chemicals on them. I had a hard time finding one that doesn't have stuff added. The one that came with the soldering station is in a bad shape.

I've become fond of using brass turnings to wipe the tip but another
possibility is to use pieces of an old cotton t-shirt. No water, just
wipe quickly. Yes, it will scorch some but it cleans the tip fairly
well and doesn't cool it down appreciably. (Note: cotton NOT polyester
or a blend.)

On Tuesday, April 2, 2013 5:29:07 PM UTC-7, John Larkin wrote:
Usually the flux in rosin-core electronic solder is all you need. I
rarely add additional liquid flux.

I see the experts at work use flux all the time. My guess is that it's needed for 1-Lead free soldering, 2-Surface mount components with very small pitch?

Flux reacts with and removes the surface oxides at the joint, allowing
the solder to wet the metals and make a good connection. It's like
trying to glue two sheets of waxed paper together with a water-based
glue ('white glue' like Elmer's). No wetting, no sticking. With the
flux, it's as if the wax were removed and you're gluing two sheets of
plain paper.

When hand-soldering a fine pitch SMT part, pre-fluxing the pads on the
board and the leads on the device encourages the solder to flow into
the space between each lead and its corresponding pad, rather than
bunching up into solder bridges.

On Tuesday, April 2, 2013 7:01:39 PM UTC-7, Phil Allison wrote:
** When you touch the tip against a joint, immediately apply a little solder
to tip so the hot solder carries the heat around.

This is more or less what I used to do and solder seemed to melt easier this way. However I read in many places where they tell you this is a big NO NO.

It is A Bad Thing to load the tip with solder and then just wipe it on
the joint or to feed the solder only onto the iron's tip. That may
look okay (from a distance) but there's little or no wetting and so
the joint is very weak.

However, having just a little dab of solder on the tip can help in
heat transfer. The goal is to heat the lead and the pad together and
then feed the solder into the joint.

On Tuesday, April 2, 2013 7:37:39 PM UTC-7, Michael Black wrote:
If the iron wasn't tinned right at the beginning, then the tip gains some
coating that causes the solder to just roll off.

But even with tinning the burnt flux still coats the tip. I will retry reducing the temp as everyone is suggesting.

700 F is a typical tip temperature to use with 60-40.

For the gunk that's already on there, Radio Shack (among others, but
you probably don't pass those others on the drive home) sells a little
tin of "tip cleaner." Wipe the tip clean after using the cleaner and
then "wash" it with a couple applications of your regular solder.

Some of the irons in the lab here aren't very well taken care of (the
desoldering irons seem to get it the worst) but this stuff goes a long
way to getting them back in shape.

On Tuesday, April 2, 2013 5:51:44 PM UTC-7, Rich Webb wrote:
Once the OP has started breathing again, he might want to look for
something like <http://www.howardelectronics.com/xytronic/lf369D.html
It's not a knock-off brand and is reasonably inexpensive (as these
things go). Some (of many more) alternates are over at
http://www.circuitspecialists.com/soldering-stations> where they have
house-branded stations. Haven't tried these but I've purchased other
stuff from them in the past w/o complaints.

Rich, I have this: http://www.circuitspecialists.com/csi-station1a.html

Looks good. Do turn the temperature down a bit, though.

 

[M. Hamed]

Thanks for all the help.

On Tuesday, April 2, 2013 4:50:39 PM UTC-7, Tim Wescott wrote:

Discolors how? If it turns brown it's not the solder -- it's the flux.
If it turns gray, then the solder is oxidizing. The flux getting a bit
brown isn't that bad, but either one of these things happening is an
indication of your iron being too hot. You probably can't get away from
this easily without using a temperature-controlled iron.

Yes, it is brownish with some blue. You're right it's most likely the flux.
I do have a temperature controlled station. I looked last night at the temperature setting and it was about 750-800.

If you have tip cleaner or a damp sponge that'll work well, too. The tip
needs to be tinned, but more importantly it needs to be clean.

So do I need to clean every time before applying solder?

They (and I) use a _damp_ sponge -- if it's dripping, it's way too wet:
it'll freeze the solder on the tip and stick the gunk on solid.

Yes, I am realizing now my sponge had too much water. I tried the scotch bright cleaning sponges but I didn't know they had extra chemicals on them. I had a hard time finding one that doesn't have stuff added. The one that came with the soldering station is in a bad shape.

On Tuesday, April 2, 2013 5:29:07 PM UTC-7, John Larkin wrote:

Usually the flux in rosin-core electronic solder is all you need. I
rarely add additional liquid flux.

I see the experts at work use flux all the time. My guess is that it's needed for 1-Lead free soldering, 2-Surface mount components with very small pitch?

On Tuesday, April 2, 2013 7:01:39 PM UTC-7, Phil Allison wrote:

** When you touch the tip against a joint, immediately apply a little solder
to tip so the hot solder carries the heat around.

This is more or less what I used to do and solder seemed to melt easier this way. However I read in many places where they tell you this is a big NO NO.

On Tuesday, April 2, 2013 7:37:39 PM UTC-7, Michael Black wrote:

If the iron wasn't tinned right at the beginning, then the tip gains some
coating that causes the solder to just roll off.

But even with tinning the burnt flux still coats the tip. I will retry reducing the temp as everyone is suggesting.

The guides all say that, but most people do melt some solder on the tip as
it is held against the joint. The melted solder helps the heat to flow.
Once there is a bit of solder on the joint, the heat flows more easily.

Oh, Thank you! That was my experience too. I always felt guilty about it though

You don't want a lot of solder on a tip, at least when you are soldering,
yet keeping some solder on the tip protects it. So you pull your iron out
of the stand, briefly wipe it on the sponge (paper towels work too, I
don't even bother dampening them) before you solder, and then before you
put the iron back in the stand (at least if it will be sitting there for a
while), add a bit more solder.

So you're saying tinning should be done after soldering the joint, not before? Could you describe how you typically tin the tip? Just touching it to the solder wire seems to concentrate solder on one side of the tip. If I wipe it with the sponge, I don't know if it stays there or not.

On Tuesday, April 2, 2013 9:00:59 PM UTC-7, Phil Allison wrote:

** There are two common reasons why beginners have problems soldering:
1. They are using a shit awful soldering iron.
2. They are using lead free or flux free solder.
Hamed, like most, has not revealed what HE is using.

Phil, I do not use lead free, except if I have to do some soldering at work.. Mainly when the job is too easy it is embarrassing to send to the tech. I use leaded solder with my home projects (which haven't been so many).

On Tuesday, April 2, 2013 5:51:44 PM UTC-7, Rich Webb wrote:

Once the OP has started breathing again, he might want to look for
something like <http://www.howardelectronics.com/xytronic/lf369D.html
It's not a knock-off brand and is reasonably inexpensive (as these
things go). Some (of many more) alternates are over at
http://www.circuitspecialists.com/soldering-stations> where they have
house-branded stations. Haven't tried these but I've purchased other
stuff from them in the past w/o complaints.

Rich, I have this: http://www.circuitspecialists.com/csi-station1a.html

---------------------------
Sorry for the long post.

 

[Phil Allison]

"M. Hamed"

Phil Allison wrote:

** When you touch the tip against a joint, immediately apply a little
solder
to tip so the hot solder carries the heat around.

This is more or less what I used to do and solder seemed to melt easier this
way. However I read in many places where they tell you this is a big NO NO.


** I have just seen a site where the writer gives this and other WRONG
advice too.

It is a common mistake to apply solder to the tip and then carry it to the
joint - but that is NOT my advice.

The idea is to AID the tip in heating the joint FAST by *re-tinning* it as
you go.

So, after applying the tip, add a dab of solder - then as the solder flows
around add a more to the joint itself.

Good soldering is done very quickly, blink and you will miss it.

A slow motion, close up vid would be good.



.... Phil

 

[Phil Allison]

"Phil Allison"

** When you touch the tip against a joint, immediately apply a little
solder to tip so the hot solder carries the heat around.

This is more or less what I used to do and solder seemed to melt easier
this way. However I read in many places where they tell you this is a big
NO NO.


** I have just seen a site where the writer gives this and other WRONG
advice too.

It is a common mistake to apply solder to the tip and then carry it to the
joint - but that is NOT my advice.

The idea is to AID the tip in heating the joint FAST by *re-tinning* it as
you go.

So, after applying the tip, add a dab of solder - then as the solder
flows around add a more to the joint itself.

Good soldering is done very quickly, blink and you will miss it.

A slow motion, close up vid would be good.

** This one will do nicely....

http://www.youtube.com/watch?v=Tuw2ir2JKM8


.... Phil

 

[Phil Allison]

"Phil Allison"

** This one will do nicely....

http://www.youtube.com/watch?v=Tuw2ir2JKM8

** You may have to copy and paste the link into YouTube.



..... Phil

 

[Michael A. Terrell]

Phil Hobbs wrote:

If the leads are oxidized like that, switching to RA-flux solder will
improve your life. I have a bunch of old parts that I still use, and RA
is the bomb.

So is a small solder pot where you can clean & re-tin the leads at
the same time. I used one for years to clean the pins on used ICs, and
old stock components. It's easier to deflux loose components than ones
in an assembly.


--

Politicians should only get paid if the budget is balanced, and there is
enough left over to pay them.

Sometimes Friday is just the fifth Monday of the week.