Tools for desoldering?

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I'm not very skilled with soldering but I have a bunch of components
I need to replace. I have a solder pump and copper wick. I can get
the job done with these, but it's slow work. Maybe with more practice
I'd improve, but as it stands, I end up using the pump 3 or 4 or
more times before I get most of the solder up. I'm not too successful
with the wick at all.

So I'm considering buying something fancier. I'm willing to spend
$100 or so, perhaps more if something is really highly recommended.

All suggestions appreciated.

Re: Tools for desoldering?




Hamad bin Turki al Salami wrote:

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Where's it going wrong ? I can manage with a pump and wick just fine but
technique is everything. The quality of the wick varies hugely too ! As do pumps
in fact, come to think of it.

Give us some more details.

Graham



Re: Tools for desoldering?



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I prefer wick.

Sometimes it helps to apply fresh solder first, to get things flowing, and
then apply the wick.

I presume you are placing the wick between the soldering iron and the joint?

Are you using "no-clean" wick?  I prefer the full-fat variety.  You can
often tell from the colour of the reel.  No-clean is usually green.  The red
reels have more flux.

Are you desoldering SMD or through-hole?



Re: Tools for desoldering?




Andrew Holme wrote:

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That often helps.


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Me too. It's all about introducing some more flux into the area.


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That's manufacturer dependent. The best wick I've ever used btw is 'Soder Wick'
(tm).

Wick and pumps have slightly different applicability too.

Graham


Re: Tools for desoldering?



Hamad bin Turki al Salami wrote:
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Hi, Hamad.  Possibly your desoldering pump is worn out, broken, or
hasn't been cleaned properly.

I'm assuming you've got something like this:

http://rocky.digikey.com/WebLib/OK%20International/Web%20Photo/DP-100.jpg

If you're doing through hole work, they're invaluable because they're
much quicker (and a lot less expensive) than solder wick.  I just grab
the solder with the pump, one click, and I'm done.  Since they're
faster than wick, there's less chance of cooking the part if you might
want to reuse it.  For SMT parts, though, they're generally not too
useful, because they'll just suck up the part along with the solder.

You don't always get what you pay for, but you'll always pay for what
you get with these.  Better quality manual desoldering pumps have
better rings and seals and higher quality teflon nozzles which won't
melt or deform under heat.  Try an aggressive cleaning of the pump,
paying close attention to the seals and rings.  Also, replace the tip
if it's deformed and a replacement tip is available.  You can't get
good suction if you're not on the solder joint.  If that doesn't work,
then replace the thing.

Although they're very useful for fine work, the expensive setups are
probably overkill for most basic work.  Just try getting a good basic
tool, and go with that.

Good luck
Chris


Re: Tools for desoldering?




Chris wrote:

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You can get service parts for them.

The seals and nozzles wear out quite quickly and *have* to be replaced
periodically.

Never *ever* clean the solder slag off the 'prong' of a pump with a pair of
serrated pliers btw. It'll totally wreck it.


Graham


Re: Tools for desoldering?



This is way over $100, but for removing SMD parts I really like the
way the Metcal Talon works.  Like others said, sometimes you have to
add solder to get good heat connectivity, but at least with the Talon
you just grab the part and remove it.  I've used it for some
through-hole parts too, if the leads are arranged such that the tips
can melt them all at once.

With a regular iron, one trick that sometimes works is to add more
solder such that all the pins bridge.  Then you can sometimes melt
them all at once and lift that side of the part up.

Re: Tools for desoldering?


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One thing that I find helps a lot if I don't have to recover the parts
intact, is to just just cut the leads of the through hole components in
need to replace so you only have to work with one pin at a time.  I then
heat the remaining leads with my soldering iron and remove them with
needle nose pliers.  The last step is to mount the board in a vise, heat
one side with the soldering iron and suck the solder out the other side.
I find this method gives you nice clean holes and minimizes board
damage.  One thing that you want to be careful of when using a hand held
solder pump is to hold the tip steady when you trip the pump.  If you
allow the tip to slide across the boare, you risk damaging the solder
pad on the board, particulary if you have to apply a lot of heat to get
the solder to melt on both sided of a multi-layer board.

If this is something you'll be doing a lot, then you ought to consider
buying a temperature controlled desoldering station.  I personally
prefer Hakko's stations, but there are others.  Unfortunately, one of
those is quite a bit more than your $100 budget even if you are patient
and buy it off eBay.  If you go this way, make sure you get one with a
built-in vacuum pump unless you have shop air available.

Hakko does have a hand-held desoldering tool that heats and generates
it's own vacuum.  I've seen it offered by eBay sellers for $165 or so.
I haven't used one so I can't comment on how easy they are to use but
you might ask for input from others.

Good luck.

--
James T. White



Re: Tools for desoldering?


On Fri, 22 Dec 2006 16:21:47 -0600, "James T. White"
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<snip>

For completeness (and more divergent from the OP's
question), sometimes you may need to do the opposite
of the above, and recover parts from a board that is
to be scrapped.  Many years ago I hit upon (literally!)
a quick-and-dirty approach that needs no special
tools... just a work surface you don't care too much
about.  You heat up each solder pad, then *WHACK*
the board  sharply against the workbench, solder pad
down.  Inertia removes the solder as a nice splash spot
on your bench, but it doesn't actually hurt anything and
can usually be peeled right off.  (Of course, you can
always use a protective layer of scrap wood or something.)
Do this for each pin, then wiggle it a little with the needle nose
to make sure it's free.

I rescued lots of "too good to toss" stuff from the scrap bin
of my employer back in the '70s.  Ahh, the good old days!

Best regards,


Bob Masta
dqatechATdaqartaDOTcom
 
            D A Q A R T A
Data AcQuisition And Real-Time Analysis
           www.daqarta.com
Home of DaqGen, the FREEWARE signal generator

Re: Tools for desoldering?



Bob Masta wrote:

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You can also heat bigger section of the board over a gas range, or by
waving a blow torch or paint stripper over the board, then whack it
component side down. With a bit of luck the entire component will come
out cleanly. I've done this once to remove a 40 pin connector from a
scrap board.


Re: Tools for desoldering?


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   That kind of impact isn't good for some parts, like crystals.

Re: Tools for desoldering?



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How's ten bucks?
http://www.radioshack.com/sm-45-watt-desoldering-iron--pi-2062731.html

The tips are replaceable and cheap, but you do have to clean it out
pretty often.

Have Fun!
Rich


Re: Tools for desoldering?




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Of all the many methods I have tried this does the most work the best and
easiest. YMMV.




Re: Tools for desoldering?


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For about three decades now, I've been saying, "gotta get me a little
vacuum pump and trigger switch..." The ones with the electric pump are
much nicer, but cost 10-20 times as much. ;-)

Cheers!
Rich


Re: Tools for desoldering?


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I've got a pile of those new in the package. I seems over time, every
time went to Radio Shaft, I could never remember if i had a spare unit
so i would some times buy one those and maybe one 15 and 30 iron..
   One day i decided to clean up, after throwing away a lot of junk. I
now have aprox 8 desolder units like that from radio shaft and about 12
or various irons all new in packages.
   I stopped buying those things when i got my high end
solder/desoldering station. I save those for portable use now :)


--
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Real Programmers Do things like this.
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Re: Tools for desoldering?


On Fri, 22 Dec 2006 02:15:32 -0700, Hamad bin Turki al Salami

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The OK Tools Soldapult is definitely the best tool for removing solder
from most components but often it is necessary to make several
attempts along with  added flux and/or solder, especially for IC's or
multi-pinned items.

Many pcb designers err towards the smallest through-holes necessary
for component mounting, even when it comes to low density designs.
They seem to completely ignore (perhaps deliberately in some cases)
the problems they create for board level repairs by not leaving
sufficient clearance around the component lead through-hole. When it
comes to desoldering, the closer the component lead is to the plated
through-hole, the more difficut it is to remove all solder. In some
cases I have been defeated even when using a Hakko 474 vacuum
desoldering tool.
http://www.hakko.com/english/products/hakko_474.html

Because you can't move the lead sufficiently far enough from the side
of the hole some minute solder wicking remains. On IC's with many pins
you only need this to happen on several pins to make it very difficult
to remove the component without damaging the through-holes. (PCB
designers please note)

I am currently in the process of salvaging components from an 80's
vintage Sagem teleprinter and I truly thank the board designers for
making the through holes extremely generous. Every component has been
easy to remove without any damage. The only problem is that the leads
have been bent almost flat on the solder side but judicious side
pressure with the desoldering tip usually gets them upright again.
Unfortunately this isn't so easy with a standard soldering iron and
manual solder sucker (OK Soldapult).

Re: Tools for desoldering?


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Well, clearly the vacuum station is the best bet - I've found that
giving the pin a little wiggle lets all of the solder loose, and
if you continue to wiggle it as it cools, the chip will just fall out.
(the inrush of room air cools the joint).

But, when you don't have a vacuum station, I've found that the Solder
Sucker trick works _most_ of the time; sometimes I've had to follow
up with wick, sometimes from both sides of the board.

With SMT, of course, this is all moot. :-)

Cheers!
Rich


Re: Tools for desoldering?



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That is the correct technique but it isn't that simple if there is no
room in the hole to wriggle the lead. Round pins are especially
problematic in too-small holes. Also, even with ALL solder removed
from around IC pins you will inevitably find that minute traces will
remain on the top side of the board at the pin shoulders where no air
flow can penetrate. Providing that the pcb is made by a reputable
maker and through-hole plating is reliable, gentle upward leverage at
each corner will break these minute bonds without doing any damage. I
have found some cheap boards where part of the through-hole will come
out still stuck to the pin. This problem is exacerbated when trying to
remove turned-pin IC sockets (not done very often) because these have
shoulders which remain in contact with the top plating a full 360
degrees, whereas IC pin shoulders only make contact at two points.

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Re: Tools for desoldering?


...
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Yabbut, the reason to use sockets is so you don't _have_ to unsolder
anything! :-)

Cheers!
Rich


Re: Tools for desoldering?


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   I heat the pin with the end of a soldering iron tip, and as soon as
it melts enough to break the bond I let go. It works almost every time.
If you apply the heat too long, it will reflow and bond the pin back to
the PTH.


--
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prove it.
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