I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

Maybe there were some instructions which I should have received (or
kept); anyway instead of the solder 'wetting' the copper and spreading
along the braid, which is what I assume is supposed to happen, it
barely penetrated it at all.

Maybe I needed a much bigger and hotter iron for desoldering than I
would use to solder.

Maybe the copper has become too oxidised after long disuse; I don't
know how old it was when I got it, and now it's years older.

I've now got some SMD devices to remove/fit (alas) so having braid that
works may become important. Apparently the suction tool I used to use
on larger components isn't so good at removing solder from these tiny
new parts.

Is one supposed to treat the braid in some way? Soak it in a suitable
flux? Or just buy some new pre-treated variety ?


--
Windmill, Use t m i l l
@ O n e t e l
. c o m

On Wed, 3 Aug 2011 03:42:25 GMT, lid
(Windmill) wrote:

I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

Maybe there were some instructions which I should have received (or
kept); anyway instead of the solder 'wetting' the copper and spreading
along the braid, which is what I assume is supposed to happen, it
barely penetrated it at all.

Maybe I needed a much bigger and hotter iron for desoldering than I
would use to solder.

Maybe the copper has become too oxidised after long disuse; I don't
know how old it was when I got it, and now it's years older.

I've now got some SMD devices to remove/fit (alas) so having braid that
works may become important. Apparently the suction tool I used to use
on larger components isn't so good at removing solder from these tiny
new parts.

Is one supposed to treat the braid in some way? Soak it in a suitable
flux? Or just buy some new pre-treated variety ?

I've only ever used it successfully with a 50W Weller temperature
controlled iron set to around 270 deg C. Anything piddly like the low
thermal mass 15W iron I had to use at the weekend might cause problems
on anything but the smallest pad.

Oxidisation won't help but a wipe with some fluxite or other resin
type plumbing flux might help, but its dirt cheap to buy - Chemtronics
stuff is good quality and available from Farnell and CPC for a couple
of quid.

Depending on what you are soldering you might get away with a suction
tool maybe with a smaller nozzle. The pads don't always need to be
100% flat and solder free before applying solder paste and the
replacement component.


--

The Other Mike writes:

tool maybe with a smaller nozzle. The pads don't always need to be
100% flat and solder free before applying solder paste and the
replacement component.

Solder paste! That may help.

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost

In article ,
Windmill wrote:
tool maybe with a smaller nozzle. The pads don't always need to be
100% flat and solder free before applying solder paste and the
replacement component.

Solder paste! That may help.

I tend to use a small diameter (0.5mm) multicore. But it's not the sort of
thing you'll get in Maplin. The standard 1.2mm stuff is way too big. And
leaded, of course. Stay well clear of lead free solder.

However, this is for very limited use. If doing much in the way of surface
mount repairs, you really need the correct equipment and materials.

--
*Eagles may soar, but weasels don't get sucked into jet engines *

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Windmill
writes
The Other Mike writes:

tool maybe with a smaller nozzle. The pads don't always need to be
100% flat and solder free before applying solder paste and the
replacement component.

Solder paste! That may help.

Solder paste is great for hot air rework but not really meant for manual
soldering. More normal is to use a little flux and some uber fine SMD
solder. eg he

http://www.rapidonline.com/Tools-Fas...ork-jelly-and-
solder-pack/60029/kw/

or http://preview.tinyurl.com/4qbxam

Don't dream of using lead free solder, SMD rework stuff is tin/lead with
a little silver, the stuff I pointed to is 28swg.

For discretes, wipe a little flux over the pads, add a little solder to
one pad, place comp, hold down and melt solder on pad, then solder other
pad with as little heat as poss to avoid re-melting other end. Add more
solder to other end if reqd.

For multilead, wipe flux, add a little solder to corner pads and do
pretty much as for discretes to fix the corners, then solder each pad in
turn. Ignore any bridges as you go (other than remembering to use less
solder on next pin) then use fine (re)fluxed braid to remove bridges or
excess solder.

On lead pitch from your other reply, I assume you were saying 65 thou,
which is 1.65mm. No big prob with that, down to 1.27mm should go ok with
that technique.

Advice on cut out to replace multileads is still valid, v fine flush
cutters are required, usually v expensive but these should do:
http://cpc.farnell.com/TL0991202

I'd be wary of using any kind of hot air gun, even with a good one with
a fine nozzle as it is all to easy for the inexperienced to end up with
heat damage or more loose components that expected ;-). Only exception
would be J lead devices where contact bends under the device which are v
tricky to hand solder.

Don't forget the magnifying glass (or magnifying specs).

Good luck.
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********

In article , Windmill
writes
I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

Maybe there were some instructions which I should have received (or
kept); anyway instead of the solder 'wetting' the copper and spreading
along the braid, which is what I assume is supposed to happen, it
barely penetrated it at all.

All the stuff I've used is fluxed but I do give it a wipe over with a
flux pen immediately before use for better effect (you could equally
well dip it in flux).

Maybe I needed a much bigger and hotter iron for desoldering than I
would use to solder.

You don't say what size you're using, I use a temperature controlled
iron of 35-40W but anything 25W+ should do the but watch for overheating
if not temperature controlled.

I've now got some SMD devices to remove/fit (alas) so having braid that
works may become important. Apparently the suction tool I used to use
on larger components isn't so good at removing solder from these tiny
new parts.

Are these just discretes or multipin devices? If simple 2 pin stuff then
don't try to desolder them but add a bit more solder to each pad then
flip the bit of the iron between each end of the device until the solder
at both ends is molten and flip/slide the component off. Then use braid
to clean up the pads. For multi leaded devices either use well
constrained hot air reflow device or cut all the pins, remove the body
then wipe the pins off with the iron and clean up the pads with fluxed
braid.

Watch the heat or the pads will lift. If v delicate, (particularly on
multipin) wipe the pad in the direction away from the attached track.
Practice on some scrap veroboard or similar to get the feel of what you
can get away with.

What size are the components, what's the lead pitch if multipin and what
size is the braid? Is the braid branded?
--
fred
FIVE TV's superbright logo - not the DOG's, it's ********

fred writes:

Are these just discretes or multipin devices? If simple 2 pin stuff then
don't try to desolder them but add a bit more solder to each pad then
flip the bit of the iron between each end of the device until the solder
at both ends is molten and flip/slide the component off. Then use braid
to clean up the pads. For multi leaded devices either use well
constrained hot air reflow device or cut all the pins, remove the body
then wipe the pins off with the iron and clean up the pads with fluxed
braid.

Watch the heat or the pads will lift. If v delicate, (particularly on
multipin) wipe the pad in the direction away from the attached track.
Practice on some scrap veroboard or similar to get the feel of what you
can get away with.

Sounds like great advice, thank you. I'd half forgotten how easy it was
to cause a track to lift (it's been years).

What size are the components

Varies. Some filter capacitors, some double diodes, and some tiny
multipin stuff. (There are actually two different jobs, which I thought
I'd combine to avoid forgetting and relearning).

, what's the lead pitch if multipin

I'll need to look it up, but ISTR .065

and what
size is the braid? Is the braid branded?

I just went looking for it, and can't find it. Maybe I threw it away in
disgust last time!

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost

In article ,
Windmill wrote:
I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

Maybe there were some instructions which I should have received (or
kept); anyway instead of the solder 'wetting' the copper and spreading
along the braid, which is what I assume is supposed to happen, it
barely penetrated it at all.

Re-flow the joint with a spot of multicore before using the braid. You
also need an iron powerful enough.

--
*The only difference between a rut and a grave is the depth.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" writes:

In article ,
Windmill wrote:
I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

Maybe there were some instructions which I should have received (or
kept); anyway instead of the solder 'wetting' the copper and spreading
along the braid, which is what I assume is supposed to happen, it
barely penetrated it at all.

Re-flow the joint with a spot of multicore before using the braid. You
also need an iron powerful enough.

May have to buy another. 6W not on, 15W still too small, 150 and 500W
way too big.

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost

In article ,
Windmill wrote:
Re-flow the joint with a spot of multicore before using the braid. You
also need an iron powerful enough.

May have to buy another. 6W not on, 15W still too small, 150 and 500W
way too big.

A good 15 watt like an Antex with a suitable bit would do it - but you
might have to wait for it to re-heat between 'hits'.

A 50 watt low voltage temperature controlled is the norm for electronics.
If cash is tight, I'd go for a good make secondhand (Weller, Antex) rather
than a new cheapie. Spares more easily available.

--
*Drugs may lead to nowhere, but at least it's the scenic route *

Dave Plowman London SW
To e-mail, change noise into sound.

In article , Dave Plowman (News)
scribeth thus
In article ,
Windmill wrote:
Re-flow the joint with a spot of multicore before using the braid. You
also need an iron powerful enough.

May have to buy another. 6W not on, 15W still too small, 150 and 500W
way too big.

A good 15 watt like an Antex with a suitable bit would do it - but you
might have to wait for it to re-heat between 'hits'.

A 50 watt low voltage temperature controlled is the norm for electronics.
If cash is tight, I'd go for a good make secondhand (Weller,

Excellent Irons thinness the TCP series. I've had one albeit re built a
few times since the early 90's ;!..

As to the original problem that solder wick is useless if its a
slightest bit tarnished (oxidised) I always use a solder sucker and with
careful .. use not lifted a track for years....

Antex) rather
than a new cheapie. Spares more easily available.


--
Tony Sayer

In article ,
tony sayer wrote:
A 50 watt low voltage temperature controlled is the norm for
electronics. If cash is tight, I'd go for a good make secondhand
(Weller,

Excellent Irons thinness the TCP series. I've had one albeit re built a
few times since the early 90's ;!..

After lots of experimenting I decided there was nothing on the market (at
a price I could afford) that did everything I wanted, so I built my own.
And have never regretted it. But I like Antex handsets. So based it around
them. The desolder one is Pace.

As to the original problem that solder wick is useless if its a
slightest bit tarnished (oxidised) I always use a solder sucker and with
careful .. use not lifted a track for years....

I rarely use braid since I have a desolder unit, but when I do have never
found it tarnished. Dry workshop. ;-) It's oxide on the joint that stops
it working - so as I said re-flow it before using the braid. Try it. ;-)

--
*Horn broken. - Watch for finger.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
Windmill wrote:
I've now got some SMD devices to remove/fit (alas) so having braid that
works may become important. Apparently the suction tool I used to use
on larger components isn't so good at removing solder from these tiny
new parts.

If the normal resistors etc use a bit large enough to do both ends at
once, and use tweezers etc to remove. If an IC snip all the leads first
and then remove them individually. Clean up with solder braid afterwards.
Basically, you aim to avoid damage to the PCB even at the expense of the
component being removed.

If you do this a lot get a hot air re-work station - they've come down in
price dramatically.

--
*Confession is good for the soul, but bad for your career.

Dave Plowman London SW
To e-mail, change noise into sound.

"Dave Plowman (News)" writes:

If the normal resistors etc use a bit large enough to do both ends at
once, and use tweezers etc to remove. If an IC snip all the leads first
and then remove them individually. Clean up with solder braid afterwards.
Basically, you aim to avoid damage to the PCB even at the expense of the
component being removed.

Goes against all instinct, for someone who grew up when components were
very expensive, but you're clearly correct.

If you do this a lot get a hot air re-work station - they've come down in
price dramatically.

Hopefully it'll be a one-shot job.

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost

On Wed, 03 Aug 2011 03:42:25 +0000, Windmill wrote:

I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

I've never had much success with the stuff, either. OTOH a *good* solder
sucker works well for me (I also had a cheapo plastic-bodied thing that
was a freebie. It sucked, but not in the right sense. I took a hammer to
it)

cheers

Jules

In article ,
Jules Richardson wrote:
I've never had much success with the stuff, either. OTOH a *good* solder
sucker works well for me (I also had a cheapo plastic-bodied thing that
was a freebie. It sucked, but not in the right sense. I took a hammer to
it)

If you do a lot, a de-solder station make life easy. If you don't mind a
large old unit they can be bought quite reasonably secondhand.

--
*You're just jealous because the voices only talk to me *

Dave Plowman London SW
To e-mail, change noise into sound.

Jules Richardson writes:

I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.
It never worked.

I've never had much success with the stuff, either. OTOH a *good* solder
sucker works well for me (I also had a cheapo plastic-bodied thing that
was a freebie. It sucked, but not in the right sense. I took a hammer to
it)

The one I have (or had; where is it anyway? Scratches head) tended to
kick back excessively, but removed solder.
However I gather that braid may be the only way to remove solder
bridges across tiny multi-lead SMD ICs.

In which case I need to get some that can work, and learn how best to
use it.

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost

In article ,
Jules Richardson writes:
On Wed, 03 Aug 2011 03:42:25 +0000, Windmill wrote:

I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

I've never had much success with the stuff, either. OTOH a *good* solder
sucker works well for me

Same here. You just need 4 hands (OK, you can do it with 3...)

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On Thu, 4 Aug 2011 21:54:55 +0000 (UTC),
(Andrew Gabriel) wrote:

In article ,
Jules Richardson writes:
On Wed, 03 Aug 2011 03:42:25 +0000, Windmill wrote:

I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

I've never had much success with the stuff, either. OTOH a *good* solder
sucker works well for me

Same here. You just need 4 hands (OK, you can do it with 3...)

Desoldering braid was great, but I suspect it has been rendered
useless these days by environmentally friendly, biodegradable,
recylable ingredients.

I used to make my own, copper braid [ The screen of a TV aerial
downlead stripped and flattened], and then drag it through a tin of
Fry's Flux. The active stuff i.e acidic.

The trick to desoldering then was to tin the extreme edge of the braid
[ to aid heat transfer] Then the solder would readily wick away from
the joint.

A thorough cleaning of the area of the board worked on would then be
needed as any exposed copper coated with the flux would become green,
gungy and powdery after a few days.


Not sure if the flux is still available but TV coax is not proper
braid anymore, so anyone wanting to produce their own would probably
have to go for comms cable RG58 or similar.


Solder suckers are O/K, but to drag a 48 pin DIL chip from a PCB was a
timre consuming task that would take seconds with a hot iron and a few
inches of braid

HN

On Wed, 3 Aug 2011 03:42:25 GMT, lid
(Windmill) wrote:

I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.


If the braid is a new reel snip off couple of cm or so to start with a
fresh end.

If it's an old reel first unwind a couple of turns of old oxidised
braid.

Either way tin the first cm or so and snip the tinned bit down to half
it's length to present a fresh end of newly tinned braid to make a
start with.

If removing big components with heavy leads first remove as much
solder from the copper pads as you can snipping used braid off as you
go.

Then quickly repeat the process before the joints cool. :-)

Derek G.



Maybe there were some instructions which I should have received (or
kept); anyway instead of the solder 'wetting' the copper and spreading
along the braid, which is what I assume is supposed to happen, it
barely penetrated it at all.

Maybe I needed a much bigger and hotter iron for desoldering than I
would use to solder.

Maybe the copper has become too oxidised after long disuse; I don't
know how old it was when I got it, and now it's years older.

I've now got some SMD devices to remove/fit (alas) so having braid that
works may become important. Apparently the suction tool I used to use
on larger components isn't so good at removing solder from these tiny
new parts.

Is one supposed to treat the braid in some way? Soak it in a suitable
flux? Or just buy some new pre-treated variety ?


--

This Looks like Finito Ruperto.

Derek G. writes:

If the braid is a new reel snip off couple of cm or so to start with a
fresh end.

If it's an old reel first unwind a couple of turns of old oxidised
braid.

Either way tin the first cm or so and snip the tinned bit down to half
it's length to present a fresh end of newly tinned braid to make a
start with.

If removing big components with heavy leads first remove as much
solder from the copper pads as you can snipping used braid off as you
go.

Then quickly repeat the process before the joints cool. :-)

Saved your advice where I can find it again.

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost

In article , Windmill spam-no-
lid writes

I've now got some SMD devices to remove/fit (alas) so having braid that
works may become important. Apparently the suction tool I used to use
on larger components isn't so good at removing solder from these tiny
new parts.

Braid is totally unsuitable for removing SMD components. You'll need
such a hot iron you'll vaporise the component and wreck the pads.

Don't use a solder sucker either, you'll wreck the pads with that too.
Use a hot-air gun (a paint stripper may do if you can fashion a nozzle
that comes to a point). Heat the component until the solder melts, turn
the board over and give the back a tap with a screwdriver handle. The
component will fall off leaving you with nice clean pads to solder the
replacement to.

--
(\__/)
(='.'=)
(")_(")

Mike Tomlinson writes:

Braid is totally unsuitable for removing SMD components. You'll need
such a hot iron you'll vaporise the component and wreck the pads.

I know nothing about SMD stuff, really (valve sockets, yes!) but some
advice seems to suggest that when "pins" are 0.05 apart, solder bridges
can easily appear unless you're very lucky, but can be removed with braid.

Don't use a solder sucker either, you'll wreck the pads with that too.
Use a hot-air gun (a paint stripper may do if you can fashion a nozzle
that comes to a point). Heat the component until the solder melts, turn
the board over and give the back a tap with a screwdriver handle. The
component will fall off leaving you with nice clean pads to solder the
replacement to.

Something I'll bear in mind if I have to remove an IC; it sounds like
it might be a non-destructive approach.

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost

Windmill wrote:
I have some desoldering braid which is supposed to assist in removing
solder from circuit boards by using capillary action to wick the solder
away from a soldered joint.

It never worked.

Maybe there were some instructions which I should have received (or
kept); anyway instead of the solder 'wetting' the copper and spreading
along the braid, which is what I assume is supposed to happen, it
barely penetrated it at all.

Maybe I needed a much bigger and hotter iron for desoldering than I
would use to solder.

Maybe the copper has become too oxidised after long disuse; I don't
know how old it was when I got it, and now it's years older.

I've now got some SMD devices to remove/fit (alas) so having braid that
works may become important. Apparently the suction tool I used to use
on larger components isn't so good at removing solder from these tiny
new parts.

Is one supposed to treat the braid in some way? Soak it in a suitable
flux? Or just buy some new pre-treated variety ?


If you strip the braiding from coax and have some sort of resin flux you
can soak it in, it works well with a hot iron.

But so does a solder pump or heating the joint and banging the PCB on
the bench to flick the hot solder off.

So does a matchstick used to crack a drying joint and make it a really
dry joint.

The Natural Philosopher writes:

If you strip the braiding from coax and have some sort of resin flux you
can soak it in, it works well with a hot iron.

But so does a solder pump or heating the joint and banging the PCB on
the bench to flick the hot solder off.

So does a matchstick used to crack a drying joint and make it a really
dry joint.

So maybe a toothpick/cocktail stick to scrape away solder from the
0.01 (?) gap between traces?

--
Windmill, Use t m i l l
@ O n e t e l
J.R.R. Tolkien: . c o m
All that is gold does not glister / Not all who wander are lost