De-soldering Advice - Loosing My Mind

[B1nary]

I was having the exact same problem re-capping an amateur radio and tried what is being suggested herein. I have a desolder gun and it wasn't helping. In fact some caps came out easily and others were a rear bear to get out. My solution was to use the de-solder gun to release the first pin of a cap, if the second pin would not come out I then used a temp controlled solder station set to 325 degrees -- far too hot normally, but I held it on the cap pin until the cap could be pulled out easily. Nothing I tried after that would remove the solder filled through hole - so I picked up a small pin vise (looks like a baby manual hand drill) and I bought small very small number drill bits. The drill bit I am using now is .61mm but you can buy them in thousand inch sizes as well. This solution works for me. A word of caution - don't be hamfisted with the pin vise or you will break the bit.

[Samogon]

This issue with caps usually due to huge thermal mass where negative pin is soldered. Usual thing for power rail filter caps. Sucking out solder from positive side, then while heating negative, wiggling out cap. Then you can use toothpick to push out solder left in the hole.   

[rsjsouza]

At $1.25 I bought a set.  Can you elaborate on their usage?

They are stainless steel so do not adhere to solder. They are also hollow like a needle. So you can heat up the joint with the wire still in the hole. Just pick the correct size needle. Get the hole hot so as to melt all the solder, and poke the needle through the hole from the other side. The hollow of the needle will allow the wire to enter it. Then when it cools, the wire is now not attached to the plating of the board. You can then remove the component. If the component wire has already been pulled out, simply do the same thing anyway, it will clean out the hole just the same.. 

THANK YOU!!! My dad had a Philips branded desoldering tool like this and it was great to use in most cases. This tool was lost and I could never find something similar.

[kalel]

For the price, they seem useful but also some care should be taken to not damage anything (I don't know how likely that is to happen).

[rsjsouza]

It can happen, kalel.

In the early days of using this tool, I recall obliterating pads while vigorously rotating it, as I thought there was solder in the hole that was blocking it from going over the other side. In fact, the size I was using was wrong and I was actually drilling a larger hole instead... 

[dl1640]

Normally I use Hakko 701 station (desoldering gun ) for best result but tap the board on a workbench is also considerable if filled with excessive solder.

[cdev]

Did you watch Dave's video on "Chip Quik"? (low temperature solder for desoldering SMDs)

[ErwinsCat]

when I  have a similar freak non-cooperating pad to desolder, usually get a peace of nic-chrome (i get them from a hair dryer or a similar heater) or a small piece of aluminum enameled/magnet wire. heat up the pad and push the wire through. If you ever tried to solder those wires you would learn very soon they (almost) impossible to solder with the normal flux and solder wire. so you push one off those into the hole and you would be sure you could pull them out without getting stuck in the holes.

[daedalux]

A injection needle of a enough size will get the wire nicely when desoldering and break the joint so the component will be free by just pulling the needle after cooling. It's a miracle for removing a dip package on the cheap for example. They are stainless steel and solder alloy won't stick to them. There are comercial devices similar with a grip and without a sharp point called desoldering needles.

[mixiom]

I have bad experience with those. Maybe they do work if the legs of the component are straight up, but many times the legs have been bend and you cannot slide the tool over the leg. Trying to bend the legs with the tool broke it apart; it is very brittle (I speak for the cheap ebay one), perhaps not real steel, I dont know. Also, many of the time the component legs are not only bend, but they are so wide that there is not enought room in the hole for the tool to slide over it; so you reach for a smaller tool diamater but that does not fit on the leg and you push and twiggle without success - it was frustrating to me. Perhaps if the circumstances (big hole, straight legs, etc) are right, this tool could work, but it is not a universal solution.

[BravoV]

A injection needle of a enough size will get the wire nicely when desoldering and break the joint so the component will be free by just pulling the needle after cooling. It's a miracle for removing a dip package on the cheap for example. They are stainless steel and solder alloy won't stick to them. There are comercial devices similar with a grip and without a sharp point called desoldering needles.

+1

Used to use just ordinary injection needles, just buy various different sizes, as they're relatively cheap and easy to get locally, at least here, and quite effective too. Only stopped using them once I got my Hakko de-soldering gun. 

Its true stainless steel and real hard & strong, and solder wont stick to it at all.

Random google images.

[daedalux]

I've succesfuly freed pcb holes:

-Adding more tin and blowing quick.
-Inserting a paperclip or needle into the fused joint.
-Not even freeing it, just inserting the new component lead in the joint and once in patiently melting both in. Not very recomended.
-Drilling it with a hand drill and an small bit, it's the only cold method and very good on a valuable board, with a well choosen bit, it will not destroy the via in the hole.
-Usually the method of choice is desoldering pump (must suck good, don't use the smallest ones) that you must learn how to use as its tricky to suck good without the joint solidifying. In smd and if refination is needed use solder wick. If the component is still in and has more than two nearby leads you must have pump, wick or both.
-Solder wick of good quality can solve anything, but it is slow and you expend it fast, and the good one is not so cheap, if it's bad you'll have to add flux to it.

[Ray Gianelli]

You won't get the solder to flow out of the hole without either A) wetting your braid with liquid flux; or B) using a solder sucker. You can use either of these approaches. Vacuum desoldering tools will also work but are very expensive compared to the above—a bottle of liquid flux is $7.50 and a high-end solder sucker can be had for as low as $6.

Agree.  The Hakko desoldering tools are not cheap, but still rate as good bang for your buck with me.

In this application tip size is critical.  You need a tip small enough to match the hole size.  Then it's quick and effective.

[mr.fabe]

You won't get the solder to flow out of the hole without either A) wetting your braid with liquid flux; or B) using a solder sucker. You can use either of these approaches. Vacuum desoldering tools will also work but are very expensive compared to the above—a bottle of liquid flux is $7.50 and a high-end solder sucker can be had for as low as $6.

Agree.  The Hakko desoldering tools are not cheap, but still rate as good bang for your buck with me.

In this application tip size is critical.  You need a tip small enough to match the hole size.  Then it's quick and effective.

I was in the market for the Hakko FR-300 and I stumbled upon this Velleman VTDESOL3U for about $9.  This cheapo desoldering iron works great. Although it has a huge hole in the tip, with proper technique, it works extremely well.  Set the plunger, put iron over pad with the wire touching the inner edge of the iron hole. When the solder start to flow, move the tip in a circular motion around the joint and press the button for suction. Voila! Clean pads with little need for any wicking. Worked very well on boards with pads on both sides.  Pleasantly surprised with this thing.


Sent from my XT1575 using Tapatalk

[KL27x]

Using those suckers on large IC'a (old school) is still huge pain not even really worth it.. for them you really need desoldering gun.

That said i have had to use them and it is really pain in ass . You easily end using too much heat adding new solder and flux.... trying to suck it clean again.. failing redoing.. sometimes it works first go some are really stubborn pins... really pain in ass.

I avoid adding more solder/flux. Flux just clogs the sucker.

What I do is get a 3mm bevel tip on the pad then put the sucker OVER the pin and iron tip while pressing the button. (The button is the only thing moving!) Eventually you will melt a notch in the tip which fits over the iron just right, but you can speed things up and cut or file a notch. If you try to extract the tip while trying to push the tip down against the pcb and pressing the button at just the right moment, you might be doing it wrong.

A good sucker helps. I can recommend the Edsyn Sodapult and Edsyn Sodapult 3. The peak suction of a good sucker is higher than any desoldering station (if you're using it, correctly). A desoldering gun might be able to provide more heat, though, for those multilayer boards. But that depends on what soldering station you use, of course. 

[KrudyZ]

Did you watch Dave's video on "Chip Quik"? (low temperature solder for desoldering SMDs)

I second this suggestion. It really works wonders on things like shielding cans or big MOSFETs.
I use a dedicated tip to for my iron to desolder with Chip Quick solder and then completely remove the remaining solder with either a sucker or solder wick.
It does not wet well and requires some more thorough clean-up, but it's worth the effort.

[dictatim]

I have been repairing electronic equipment for nigh on sixty years and have picked up a few tips and tricks on the way.
One, relevant to this discussion, was how to deal with removing DIL ICs. Almost invariably this is done with the intention of fitting a replacement so it is not necessary to remove the old one intact. Simply using fine, sharp sidecutters (or even a sharp craft knife) cut off the pins where they emerge from the plastic body, remove the body, heat the solder and remove each pin in turn using fine tweezers.  The vias can then easily be cleared using a solder sucker.
Also, when re-capping PC motherboards, power supplies etc., I have had considerable success removing old components by using sharp, fine sidecutters to slice off the pins - together with the mound of solder - very close to the surface of the solder side of the board. Most complex boards are wave soldered and the solder doesn't actually suck up into the via so it's possible to lever the component away from the board without the need to apply any heat.
On most solder jobs it's essential to 'alloy' the existing lead free solder with 60-40 lead/tin solder to lower the melt temperature. It seems to retain its heat and stay fluid a little longer too.

[ogden]

Preheating the board with heatgun or special IR heater is key to success in through-hole (capacitor) rework on multilayer PCB. I just set around 200..250oC air temp, heat PCB bottom area around capacitor, use powerful enough soldering iron with additional lead solder for better heat transfer and no struggle at all.

[xxx2fan]

Google is your friend, Google desoldering vac from old refrigeration compressor, Should be able to find one easy they have to come out of Refrigs etc to scrap them. A filter to keep the solder out of the unit and oh well Google it.
Just a idea, have had one for years and finally got a premade one LOL not much difference except the homemade one has more suction.

[cdev]

I am using the large knife tip on my old soldering iron now for desoldering. Its really good for that.

Using those suckers on large IC'a (old school) is still huge pain not even really worth it.. for them you really need desoldering gun.

That said i have had to use them and it is really pain in ass . You easily end using too much heat adding new solder and flux.... trying to suck it clean again.. failing redoing.. sometimes it works first go some are really stubborn pins... really pain in ass.

I avoid adding more solder/flux. Flux just clogs the sucker.

What I do is get a 3mm bevel tip on the pad then put the sucker OVER the pin and iron tip while pressing the button. (The button is the only thing moving!) Eventually you will melt a notch in the tip which fits over the iron just right, but you can speed things up and cut or file a notch. If you try to extract the tip while trying to push the tip down against the pcb and pressing the button at just the right moment, you might be doing it wrong.

A good sucker helps. I can recommend the Edsyn Sodapult and Edsyn Sodapult 3. The peak suction of a good sucker is higher than any desoldering station (if you're using it, correctly). A desoldering gun might be able to provide more heat, though, for those multilayer boards. But that depends on what soldering station you use, of course.

I have a small plastic bellows pump as well as a small HEPA vacuum with foot switch that I have successfully used as one hand solder suckers. You can use a large glass bottle as a gravity trap so that the solder doesn't go into the pump/vacuum or whatever.

The Chip Quik is great stuff, a little bit of it goes a very long way. Combined with preheating especially.

[jmelson]

OK, here's my method.  First, get a solder sucker, there are a couple types.  The sucker-only types work, but you have to be very fast to heat the joint, then replace soldering iron with sucker and trip the sucker before the joint cools.  Or, there are types that have the heating element with a hollow solder tip/nozzle, that gets rid of the quick switch problem.

So, use the solder sucker to remove the old solder, it might be lead-free, and need a LOT of heat to melt.  Then, replace the old solder with lead-based (or low-temp solder, if you have it).  Replacing the high-temp lead-free solder with even tin/lead solder makes a HUGE difference.

Now, remove the component.  If a big radial capacitor, you may have to alternately heat one lead and then the other, and rock it off the board.
Once the component is removed, then you can clear the hole.  If using the sucker-only device, apply the soldering iron to whichever side of the board has more copper on the pad, let it heat for 10 seconds or so, then apply the sucker to the other side and trip the sucker while still holding the soldering iron to the other side.

If using a combined heater/sucker, then you can put a soldering iron on the other side, thus heating from BOTH sides of the board.  This works amazingly well on heavy multilayer boards like computer motherboards.  Make sure the through hole in the board is FULL of solder before doing this, the solder will help the entire hole be molten, so it gets completely sucked out.

I've not had ANY luck with desoldering braid on multilayer boards through holes.

Jon

[Southerner]

just needed regreasing.  Search for Solda Pullt and it will show up.

/quote]
What kind of grease do yo use?

[Southerner]

OK, here's my method.  First, get a solder sucker, there are a couple types.  The sucker-only types work, but you have to be very fast to heat the joint, then replace soldering iron with sucker and trip the sucker before the joint cools.  Or, there are types that have the heating element with a hollow solder tip/nozzle, that gets rid of the quick switch problem.

A third type is a desoldering tip that has a squeeze bulb coming off of it.  I tried to find one to fit my Weller WTCPT but was unable to find one even though they make them.  I ended up buying a cheap 110vac soldering pencil that had that type of desolder bulb.  They definitely work better with a temperature controlled iron though.

[Terry01]

This type of solder pump is the best mechanical pump I have had by a country mile! The electric one is good of you are doing a lot of de-soldering but for just 1 or 2 this is awesome! They are quite big though but well worth it for how easy it makes jobs like the one you are up against!

[David Hess]

A third type is a desoldering tip that has a squeeze bulb coming off of it.  I tried to find one to fit my Weller WTCPT but was unable to find one even though they make them.  I ended up buying a cheap 110vac soldering pencil that had that type of desolder bulb.  They definitely work better with a temperature controlled iron though.

A Weller DS227 vacuum desoldering head will also fit on a WTCPT iron.