EOL solder wire purchase

[Don Y]

Hi,

Many years ago, I made what I *though* would have been
my "last buy" of solder wire. Apparently, my estimated
usage was off -- or, I have lived too long. :< Either
way, I find myself having to repeat this exercise...
(the real problem is that I have been using too much of
it for "bigger jobs" instead of prototype fabrication,
touch up/rework, etc.)

[Note I am not worried about solder *paste* -- I buy that
as needed]

I figure I will need enough for ~500 (smallish) prototypes
(several square inches of PCB, components both sides) plus
miscellaneous wiring, cables, etc.

And, the sorts of things anyone "electrically/electronically
inclined" encounters in day-to-day living (repairing
appliances, TVs, etc.)

In addition to 0.028" and 0.015" 60/40 wire, recent experience
suggests I purchase some larger diameter (0.062"?) for those uses
that eat gobs of wire per connection (i.e., when you'd be
feeding half a foot just for *one* connection!)

Suggestions as to how much of which sizes? And, is this truly
a commodity product (cost being the only issue) or are there
vendors to avoid/favor? (I've tended towards kester over the
years -- but for no "real reason")

Digikey? Or, "anyplace local" (taxes vs. shipping fees)?
Figure ~$30-40/pound for anything "non-esoteric"?

Thx,
--don

 

[Joerg]

Hi,

Many years ago, I made what I *though* would have been
my "last buy" of solder wire. Apparently, my estimated
usage was off -- or, I have lived too long. :< Either
way, I find myself having to repeat this exercise...
(the real problem is that I have been using too much of
it for "bigger jobs" instead of prototype fabrication,
touch up/rework, etc.)

[Note I am not worried about solder *paste* -- I buy that
as needed]

I figure I will need enough for ~500 (smallish) prototypes
(several square inches of PCB, components both sides) plus
miscellaneous wiring, cables, etc.

And, the sorts of things anyone "electrically/electronically
inclined" encounters in day-to-day living (repairing
appliances, TVs, etc.)

In addition to 0.028" and 0.015" 60/40 wire, recent experience
suggests I purchase some larger diameter (0.062"?) for those uses
that eat gobs of wire per connection (i.e., when you'd be
feeding half a foot just for *one* connection!)

Suggestions as to how much of which sizes? And, is this truly
a commodity product (cost being the only issue) or are there
vendors to avoid/favor? (I've tended towards kester over the
years -- but for no "real reason")

Digikey? Or, "anyplace local" (taxes vs. shipping fees)?
Figure ~$30-40/pound for anything "non-esoteric"?

More like close to fifty bucks for the good stuff. Ouch, ouch.

And yeah, it's commodity products. Kester makes a leaded no-clean in
0.062" but personally I haven't used their 8817 yet (well, maybe at
clients without realizing it):

http://www.digikey.com/product-search/en?vendor=0&keywords=KE1399-ND

 

[Don Y]

Hi Joerg,

More like close to fifty bucks for the good stuff. Ouch, ouch.

<shrug> Acceptable. It's been *decades* since I last made
a buy so I'll accept some amount of "inflation".

Any ideas as to quantities I should target? E.g., figure
500 densely populated, double-sided boards in the 6-12 sq
in (per side) range... (they are often much smaller than
this but usually "stacked" to achieve a particular volume
profile)

And yeah, it's commodity products. Kester makes a leaded no-clean in
0.062" but personally I haven't used their 8817 yet (well, maybe at
clients without realizing it):

http://www.digikey.com/product-search/en?vendor=0&keywords=KE1399-ND

"No-clean" isn't important -- especially on larger diameters
(where I might not even *have* to clean up!)

Thx!
--don

 

[Joerg]

Hi Joerg,



<shrug> Acceptable. It's been *decades* since I last made
a buy so I'll accept some amount of "inflation".

Any ideas as to quantities I should target? E.g., figure
500 densely populated, double-sided boards in the 6-12 sq
in (per side) range... (they are often much smaller than
this but usually "stacked" to achieve a particular volume
profile)

No idea but easy to find out, my wife uses the same trick to find if she
can make another teddybear from a given amount of yarn of unknown
length: Weigh your spool of solder on a very precise kitchen scale.
Solder up a storm, note the achieved square-inches. Now weigh again.

[...]

 

[Robert Baer]

Hi,

Many years ago, I made what I *though* would have been
my "last buy" of solder wire. Apparently, my estimated
usage was off -- or, I have lived too long. :< Either
way, I find myself having to repeat this exercise...
(the real problem is that I have been using too much of
it for "bigger jobs" instead of prototype fabrication,
touch up/rework, etc.)

[Note I am not worried about solder *paste* -- I buy that
as needed]

I figure I will need enough for ~500 (smallish) prototypes
(several square inches of PCB, components both sides) plus
miscellaneous wiring, cables, etc.

And, the sorts of things anyone "electrically/electronically
inclined" encounters in day-to-day living (repairing
appliances, TVs, etc.)

In addition to 0.028" and 0.015" 60/40 wire, recent experience
suggests I purchase some larger diameter (0.062"?) for those uses
that eat gobs of wire per connection (i.e., when you'd be
feeding half a foot just for *one* connection!)

Suggestions as to how much of which sizes? And, is this truly
a commodity product (cost being the only issue) or are there
vendors to avoid/favor? (I've tended towards kester over the
years -- but for no "real reason")

Digikey? Or, "anyplace local" (taxes vs. shipping fees)?
Figure ~$30-40/pound for anything "non-esoteric"?

More like close to fifty bucks for the good stuff. Ouch, ouch.

And yeah, it's commodity products. Kester makes a leaded no-clean in
0.062" but personally I haven't used their 8817 yet (well, maybe at
clients without realizing it):

http://www.digikey.com/product-search/en?vendor=0&keywords=KE1399-ND

Do NOT use "no-clean" as it (1) needs cleaning, and (2) makes for
more problems than any other formulation.

 

[Phil Hobbs]

Hi,

Many years ago, I made what I *though* would have been
my "last buy" of solder wire. Apparently, my estimated
usage was off -- or, I have lived too long. :< Either
way, I find myself having to repeat this exercise...
(the real problem is that I have been using too much of
it for "bigger jobs" instead of prototype fabrication,
touch up/rework, etc.)

[Note I am not worried about solder *paste* -- I buy that
as needed]

I figure I will need enough for ~500 (smallish) prototypes
(several square inches of PCB, components both sides) plus
miscellaneous wiring, cables, etc.

And, the sorts of things anyone "electrically/electronically
inclined" encounters in day-to-day living (repairing
appliances, TVs, etc.)

In addition to 0.028" and 0.015" 60/40 wire, recent experience
suggests I purchase some larger diameter (0.062"?) for those uses
that eat gobs of wire per connection (i.e., when you'd be
feeding half a foot just for *one* connection!)

Suggestions as to how much of which sizes? And, is this truly
a commodity product (cost being the only issue) or are there
vendors to avoid/favor? (I've tended towards kester over the
years -- but for no "real reason")

Digikey? Or, "anyplace local" (taxes vs. shipping fees)?
Figure ~$30-40/pound for anything "non-esoteric"?

More like close to fifty bucks for the good stuff. Ouch, ouch.

And yeah, it's commodity products. Kester makes a leaded no-clean in
0.062" but personally I haven't used their 8817 yet (well, maybe at
clients without realizing it):

http://www.digikey.com/product-search/en?vendor=0&keywords=KE1399-ND

Do NOT use "no-clean" as it (1) needs cleaning, and (2) makes for
more problems than any other formulation.

AFAICT "no clean" flux for leaded alloys is just good old rosin flux.

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 Devereux]

I beg to differ somewhat. There are no-clean fluxes with a rosin
base. Usually, they're classed as ROL0 (Rosin Low activation). I
don't believe they're available as a rosin core for roll solder but
might be mistaken.

We used no-clean flux with 60/40 in various wave soldering machines
back in the late 1970's and early 1980's. I hated it. No-clean flux
tended to leave a difficult to remove residue. This residue drove me
nuts with bed-o-nails test fixture contact problems and tuning drift
effects on RF circuits which weren't protected by silk screening. UV
inspection of the urethane waterproof conformal coating showed crappy
adhesion to the flux residue. Under stress, the coating would flake
off around the solder joints. The residue also appeared to be
hygroscopic and caused problems with high impedance circuits.

While none of these problems are likely to appear in the OP's hand
assembled or repaired PCB's, neither are the benefits of using
no-clean flux in a production environment likely to be useful.
Therefore, I suggest RMA (rosin mildly activated) for general purpose
use where a solvent cleaning is sometimes forgotten, and RA (rosin
activate) for repair work on ancient devices that are likely to be
coated with oxides. All my roll solder is RMA. If I need more flux,
I have a bottle and apply it with an included brush.

Why Clean No-Clean?
<http://www.assemblymag.com/articles/84286-why-clean-no-clean>

"Today, one of the most common reasons to remove no-clean fluxes is to
prevent malfunctions in circuits with clock speeds over 1
gigahertz. "When you get above 1 gigahertz, the electrons are conducted
on the outer surface of the conductor," says Stach. "If there's flux on
the conductors, it can act as a conductor, too, and interfere with the
signal.""

 

[Joerg]

"Today, one of the most common reasons to remove no-clean fluxes is to
prevent malfunctions in circuits with clock speeds over 1
gigahertz. "When you get above 1 gigahertz, the electrons are conducted
on the outer surface of the conductor," says Stach. "If there's flux on
the conductors, it can act as a conductor, too, and interfere with the
signal.""

I have never seen that happen and some of my RF and digital designs run
transitions in the few hundred picoseconds. No problems. I assume what
they mean with "conductor" is a trace. Those are supposed to be covered
with solder mask and I don't see how flux can get underneath there.

Yeah, no-clean is a bit hygroscopic but other than that I haven't had
problems with it. It's been many years now.

[...]

 

[Cydrome Leader]

Hi,

Many years ago, I made what I *though* would have been
my "last buy" of solder wire. Apparently, my estimated
usage was off -- or, I have lived too long. :< Either
way, I find myself having to repeat this exercise...
(the real problem is that I have been using too much of
it for "bigger jobs" instead of prototype fabrication,
touch up/rework, etc.)

[Note I am not worried about solder *paste* -- I buy that
as needed]

I figure I will need enough for ~500 (smallish) prototypes
(several square inches of PCB, components both sides) plus
miscellaneous wiring, cables, etc.

And, the sorts of things anyone "electrically/electronically
inclined" encounters in day-to-day living (repairing
appliances, TVs, etc.)

In addition to 0.028" and 0.015" 60/40 wire, recent experience
suggests I purchase some larger diameter (0.062"?) for those uses
that eat gobs of wire per connection (i.e., when you'd be
feeding half a foot just for *one* connection!)

Suggestions as to how much of which sizes? And, is this truly
a commodity product (cost being the only issue) or are there
vendors to avoid/favor? (I've tended towards kester over the
years -- but for no "real reason")

Digikey? Or, "anyplace local" (taxes vs. shipping fees)?
Figure ~$30-40/pound for anything "non-esoteric"?

newark is a good place for solder.

 

[Joerg]

I've never seen that either because most of my strip lines are 50 ohms
and buried under a layer of green solder mask where the flux won't
stick. ...

Even if it would stick it doesn't matter too much.

... What I have seen is the residue bridging between a solder pad
and ground as in the annular ring around a pad. We would wash, rinse,
dry, test, tune, and then watch the tuning and bias points slowly
drift. Hit the PCB with a heat gun to evaporate the water, and all
would be well for a few days. Add a little humidity (or test with a
nebulizer), and in a few hours, the tuning and bias points would again
drift. This problem was one of the reasons that the company went on a
"design with low impedances" binge. High impedances and high Q
circuits just weren't compatible with the flux processes of the day.

I have seen that with other fluxes, including some weird electrolytic
effect. A client even saw it depelop some "whitish pus" between to IC
pins. Never seen that with no-clean but, of course, if you have a very
high impedance pads close to other conducting matter you have to even
clean the no-clean. Which is harder to do than with other resin so this
may be a situation where no-clean is not the best option.

I personally contributed to making things worse. I substituted a
washable flux but didn't have a proper production line board wash
available. So, I used an ordinary dishwasher, which did a marginal
job. Washable flux is loaded with acid, which needs to be washed well
and immediately. The tuning and bias points didn't drift. Instead,
the leads and some plating disappeared, etched off by the acid
residue.

That's one reason I use no-clean. I just donated a scope to a school and
first I had to spend many hours repairing it. Turns out the mfg had not
cleaned the flux. What a mess.

By coincidence, Fairchild Semi had just switched from Epoxy B to
silicon epoxy PN style transistor packages. These had the unique
property of opening a tiny gap around the leads during wave soldering,
which allowed some flux into the transistor package. Everything
looked normal until the completed radios emerged from burnin, where
hundreds of dead transistors were found. Xrays of the dead
transistors showed that the bonding wires had disappeared. We gave up
on washable flux.

I always urge clients not to use wave-solder but use reflow instead. It
prevents a lot of problems from happening.

It really depends on the circuit. If you're doing high voltage, high
Q, or high impedance designs, I suspect there will be problems.

Yes, but that also requires measures to be taken at the layout step. Got
to be really careful with the solder mask. Sometimes we've even added
silk screen there to make things thicker or build "dams".

 

[John Devereux]

I've never seen that either because most of my strip lines are 50 ohms
and buried under a layer of green solder mask where the flux won't
stick. What I have seen is the residue bridging between a solder pad
and ground as in the annular ring around a pad. We would wash, rinse,
dry, test, tune, and then watch the tuning and bias points slowly
drift. Hit the PCB with a heat gun to evaporate the water, and all
would be well for a few days. Add a little humidity (or test with a
nebulizer), and in a few hours, the tuning and bias points would again
drift. This problem was one of the reasons that the company went on a
"design with low impedances" binge. High impedances and high Q
circuits just weren't compatible with the flux processes of the day.

I can maybe believe a capacitance change if there is moisture absorbing
crud between pads say. Or leakage in very high impedance circuits as
Joerg says. But that is not at all what the article was suggesting
AIUI.

 

[Don Y]

Hi Joerg,

No idea but easy to find out, my wife uses the same trick to find if she
can make another teddybear from a given amount of yarn of unknown
length: Weigh your spool of solder on a very precise kitchen scale.
Solder up a storm, note the achieved square-inches. Now weigh again.

D'oh! Yes, great idea! I'll just have to find a precision scale
(I don't use scales in the kitchen).

Thx!
--don

 

[Joerg]

Hi Joerg,



D'oh! Yes, great idea! I'll just have to find a precision scale
(I don't use scales in the kitchen).

Many postage scales are very precise, even cheaper ones. Like mine which
was cheap but measures down to one gram in metric mode. Otherwise ask a
neighbor who is a gourmet cook. They usually have very fancy scales.
Marble tray, smoked-glass floating see-through LCD on a gold-plated
metal post, the works. We've got one but only because of a liquidation
sale at a store.

McGyver method: Put a thin long plank on a pipe, making a see-saw. Mark
center. Place a rock at one end and the fresh spool on the other so you
have equilibrium. Now you know what 0.5lbs is. Mark distances from pipe.
Solder. Place spool on the plank again, scoot until equilibrium. Mark
new distance, determine with tape measure, calculate weight.

I bet the local Fedex depot or post office will also be friendly enough
to perform a quick before-after weighing.

 

[Don Y]

Hi Joerg,

Many postage scales are very precise, even cheaper ones. Like mine which

Mine is intended for packages. I think ~40lbs at 0.1oz (maybe 0.2?)
resolution (I would have to check to be sure -- I keep it packed away
until needed, like most things, here)

was cheap but measures down to one gram in metric mode. Otherwise ask a
neighbor who is a gourmet cook. They usually have very fancy scales.
Marble tray, smoked-glass floating see-through LCD on a gold-plated
metal post, the works. We've got one but only because of a liquidation
sale at a store.

I had a "precision balance" many years ago (e.g., the sort of thing
you would encounter in a pharmaceutical laboratory for measuring
actives and excipients -- like measuring the weight of individual
grains of sugar!). But, it was *big* (i.e., takes a lot of space
for the seldom used functionality it affords) so it was abandoned
on one of the moves. <shrug> I've not missed it...

(lab scales also tend to raise eyebrows with law enforcement
professionals... best not to go there! :< )

McGyver method: Put a thin long plank on a pipe, making a see-saw. Mark
center. Place a rock at one end and the fresh spool on the other so you
have equilibrium. Now you know what 0.5lbs is. Mark distances from pipe.
Solder. Place spool on the plank again, scoot until equilibrium. Mark
new distance, determine with tape measure, calculate weight.

I bet the local Fedex depot or post office will also be friendly enough
to perform a quick before-after weighing.

Post office would probably work. I think they have a scale in the
lobby. I would *hope* it can handle ~1 lb (smallish... no doubt
intended for *letters*). I will check next time I find myself
there (seldom). If I *know* I'll be there, I can bring a spool
of solder wire with me and see if it "notices" several inches
removed between weighings...

 

[Jeroen]

Hi Joerg,

[...]
(lab scales also tend to raise eyebrows with law enforcement
professionals... best not to go there! :< )

In the land of the free! What are you coming to?

Jeroen Belleman

 

[John Devereux]

Hi Joerg,

[...]
(lab scales also tend to raise eyebrows with law enforcement
professionals... best not to go there! :< )

In the land of the free! What are you coming to?

I bought some ebay "precision scales", quite cheap, did not pay much
attention to what I was buying. I had some idea I would use them to
count components, nuts or something. Claimed up to 0.01g resolution I
think.

I was puzzled to get a CD in the post. I realise it is the weigh
scale. Designed to look like a CD! WTF. They are built into a CD case,
clearly designed so as to look innocent to visiting law enforcement!

I expect I am on a List now...

 

[Joerg]

Hi Joerg,

On 8/12/2013 1:02 PM, Joerg wrote:
[...]


I had a "precision balance" many years ago (e.g., the sort of thing
you would encounter in a pharmaceutical laboratory for measuring
actives and excipients -- like measuring the weight of individual
grains of sugar!). But, it was *big* (i.e., takes a lot of space
for the seldom used functionality it affords) so it was abandoned
on one of the moves. <shrug> I've not missed it...

.... until just about now

(lab scales also tend to raise eyebrows with law enforcement
professionals... best not to go there! :< )

I could care less. They aren't going to tell me what I can use. A
pharmacists also raised a brow when I wanted syringes. "For oiling in
tough spots" ... "Ah, ok".

Post office would probably work. I think they have a scale in the
lobby. I would *hope* it can handle ~1 lb (smallish... no doubt
intended for *letters*). I will check next time I find myself
there (seldom). If I *know* I'll be there, I can bring a spool
of solder wire with me and see if it "notices" several inches
removed between weighings...

It will. Even the li'l post office in our town which is in a corner of a
Bel Air supermarket has a scale that measures minute quantities, yet
goes up to several pounds. But I am sure a neighbor has an electronic
kitchen scale.

 

[sms]

Hi,

Many years ago, I made what I *though* would have been
my "last buy" of solder wire. Apparently, my estimated
usage was off -- or, I have lived too long. :< Either
way, I find myself having to repeat this exercise...
(the real problem is that I have been using too much of
it for "bigger jobs" instead of prototype fabrication,
touch up/rework, etc.)

[Note I am not worried about solder *paste* -- I buy that
as needed]

I figure I will need enough for ~500 (smallish) prototypes
(several square inches of PCB, components both sides) plus
miscellaneous wiring, cables, etc.

And, the sorts of things anyone "electrically/electronically
inclined" encounters in day-to-day living (repairing
appliances, TVs, etc.)

In addition to 0.028" and 0.015" 60/40 wire, recent experience
suggests I purchase some larger diameter (0.062"?) for those uses
that eat gobs of wire per connection (i.e., when you'd be
feeding half a foot just for *one* connection!)

Suggestions as to how much of which sizes? And, is this truly
a commodity product (cost being the only issue) or are there
vendors to avoid/favor? (I've tended towards kester over the
years -- but for no "real reason")

Digikey? Or, "anyplace local" (taxes vs. shipping fees)?
Figure ~$30-40/pound for anything "non-esoteric"?

I'd just get Kester 63/37 in several sizes. The savings in buying a
no-name solder are minimal. Check craigslist too. In my area someone is
selling new rolls of Kester 63/37 solder for $15/pound in 0.015 and
0.062 diameters.

For large jobs I'm still working on a 5 pound roll I bought at the
Atlanta Hamfest in 1977.

 

[Joerg]

sms wrote:

[...]

I'd just get Kester 63/37 in several sizes. The savings in buying a
no-name solder are minimal. Check craigslist too. In my area someone is
selling new rolls of Kester 63/37 solder for $15/pound in 0.015 and
0.062 diameters.

Careful. Those probably vanished at a local business. Or fell of a truck.

It happened over in Europe where someone was selling antennas at a very
good price, better than wholesale. IIRC he was arrested later.

[...]

 

[tm]

Hi Joerg,

[...]
(lab scales also tend to raise eyebrows with law enforcement
professionals... best not to go there! :< )

In the land of the free! What are you coming to?

Jeroen Belleman

Not lab scale, a reloading scale.