In the following picture
http://home.graffiti.net/diverse:gra...net/solder.jpg
without any further treatment after removing from the boards,
one has been desoldered from a lead-free soldered board and the other from a
leaded-solder board. Particularly looking at the top pin of each capacitor
would anyone care to comment?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote in message
...
In the following picture
http://home.graffiti.net/diverse:gra...net/solder.jpg
without any further treatment after removing from the boards,
one has been desoldered from a lead-free soldered board and the other from
a
leaded-solder board. Particularly looking at the top pin of each capacitor
would anyone care to comment?

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/




It was awkward getting the illumination angle right.
The top one has a "silvery" coating to the pin and the bottom one a matt,
"dusty" ie not metallic, light greyish, coating.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:

N Cook wrote in message

In the following picture
http://home.graffiti.net/diverse:gra...net/solder.jpg
without any further treatment after removing from the boards,
one has been desoldered from a lead-free soldered board and the other from
a leaded-solder board. Particularly looking at the top pin of each capacitor

would anyone care to comment?


It was awkward getting the illumination angle right.
The top one has a "silvery" coating to the pin and the bottom one a matt,
"dusty" ie not metallic, light greyish, coating.

A silvery finish is associated with 60/40 type solder.

A dull finish is classic lead free.

Graham

Yes Rubycon is good qualty

Ken G. wrote in message
...
Yes Rubycon is good qualty


Despite my belief that it was (self-repaired) punch-through of one of these
Rubycon caps to cause an amp failure. I took each of these 470uF,50V to 55V
on a ps with no hint of problem and didn't bother to discharge them. 3 days
later I went to pack them away with lablels and the radial leads touched the
tin they were temporarily in, a flash and a bang. The same with the other
one when I tried it.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:

In the following picture
http://home.graffiti.net/diverse:gra...net/solder.jpg
without any further treatment after removing from the boards,
one has been desoldered from a lead-free soldered board and the other from a
leaded-solder board. Particularly looking at the top pin of each capacitor
would anyone care to comment?

You asked before.

I'm not clear what it's supposed to show. It's not as clear as it could be for
one thing.

Graham

Eeyore wrote in message
...


N Cook wrote:

In the following picture
http://home.graffiti.net/diverse:gra...net/solder.jpg
without any further treatment after removing from the boards,
one has been desoldered from a lead-free soldered board and the other
from a
leaded-solder board. Particularly looking at the top pin of each
capacitor
would anyone care to comment?

You asked before.

I'm not clear what it's supposed to show. It's not as clear as it could be
for
one thing.

Graham


I tried changing the angle of illumination and trying different colour
backgrounds behind the pins but it was too difficult to differentiate with
my camera and "techniques" .
The bottom one came from a lead free soldered board. Instead of a "slivery"
sweated film over the pins it was a dusty light grey (tin pest ? ) with just
the odd small spot of "silvering".
The top one was "good" overall "silvering" with just the presence of the
normal lumps of old resin or whatever that is usually present on
desoldering.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote in message
...
Eeyore wrote in message
...


N Cook wrote:

In the following picture
http://home.graffiti.net/diverse:gra...net/solder.jpg
without any further treatment after removing from the boards,
one has been desoldered from a lead-free soldered board and the other
from a
leaded-solder board. Particularly looking at the top pin of each
capacitor
would anyone care to comment?

You asked before.

I'm not clear what it's supposed to show. It's not as clear as it could
be
for
one thing.

Graham


I tried changing the angle of illumination and trying different colour
backgrounds behind the pins but it was too difficult to differentiate with
my camera and "techniques" .
The bottom one came from a lead free soldered board. Instead of a
"slivery"
sweated film over the pins it was a dusty light grey (tin pest ? ) with
just
the odd small spot of "silvering".
The top one was "good" overall "silvering" with just the presence of the
normal lumps of old resin or whatever that is usually present on
desoldering.


--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/







I think I'll have to dig out my viewing microscope/camera combo and redo the
pic, I still have that cap laying around. I just tried finding a pic on the
net of this dusty tin-pest ? surface but did not find one.

For those repairing stuff made before 2006 what is the method to best remove
the tinning from the leads from modern replacements before using ?
The distinguishing feature is that its much harder to abraid with a nail
file/sandpaper than tradional Pb/Sn "tinning". It is one of my personal
quirks to abraid all components ,ICs,trannies,R,Cs etc before soldering, as
rarely new stock replacements.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

Eeyore wrote in message
...


N Cook wrote:

In the following picture
http://home.graffiti.net/diverse:gra...net/solder.jpg
without any further treatment after removing from the boards,
one has been desoldered from a lead-free soldered board and the other
from a
leaded-solder board. Particularly looking at the top pin of each
capacitor
would anyone care to comment?

You asked before.

I'm not clear what it's supposed to show. It's not as clear as it could be
for
one thing.

Graham

I went back to the original unscaled image , although 2 cuts, they are from
the same pic taken at the same time with the same illumination
http://home.graffiti.net/diverse:gra...et/solder2.jpg
The lower lead free de-soldered cap lead and the upper a control from an
older board. Proper silvery sheen, mostly, to the old one, brighter than the
background graph paper, and totally dusty light grey for the lead-free ,
tin-pest ? desoldered one.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

N Cook wrote:

For those repairing stuff made before 2006 what is the method to best remove
the tinning from the leads from modern replacements before using ?
The distinguishing feature is that its much harder to abraid with a nail
file/sandpaper than tradional Pb/Sn "tinning". It is one of my personal
quirks to abraid all components ,ICs,trannies,R,Cs etc before soldering, as
rarely new stock replacements.

The Commission naturally expected you to destroy all your old stock.

Graham

N Cook wrote:

Eeyore wrote

I'm not clear what it's supposed to show. It's not as clear as it could be
for one thing.

I went back to the original unscaled image , although 2 cuts, they are from
the same pic taken at the same time with the same illumination
http://home.graffiti.net/diverse:gra...et/solder2.jpg
The lower lead free de-soldered cap lead and the upper a control from an
older board. Proper silvery sheen, mostly, to the old one, brighter than the
background graph paper, and totally dusty light grey for the lead-free ,
tin-pest ? desoldered one.

Yes, I can see the matt finish of the lead-free one now. That's how they're
supposed to look AIUI.

Graham

Eeyore wrote:



N Cook wrote:

For those repairing stuff made before 2006 what is the method to best
remove the tinning from the leads from modern replacements before using ?
I think if you dip the tin-plated wires in a sufficiently large quantity of
sufficiently hot SnPb solder, that should mix pretty well with any tin
plating that is already on the wires. The problem, as highlighted on the
NASA pages is that you have to dip all the way up to the component body if
you want to stop the tin whiskers, and that could damage metal-glass seals
etc. as normally the soldering temperature is not supposed to be applied
too close to the component body.

The distinguishing feature is that its much harder to abraid with a nail
file/sandpaper than tradional Pb/Sn "tinning". It is one of my personal
quirks to abraid all components ,ICs,trannies,R,Cs etc before soldering,
as rarely new stock replacements.

The Commission naturally expected you to destroy all your old stock.

Of course, because that's how we save the environment, by creating extra
waste and then manufacturing things we didn't need to.

That's why the WEEE was brought in after the RoHS, so that all of the old
component stocks could all be landfilled or burned, while the component
distributors rubbed their hands together with glee in anticipation of the
new orders.

Chris