How to Remove Solder that Won't Melt?

[true]

Hell, I use an Atten rebadge on my bench and it works fine to a point. But I also have a thermometer and have verified temperature, and I know that it can't do motherboards or PCI cards with large ground fills well, so I have a better iron for that. Yeah, it's all $$$...

[Stonent]

I am going to get crucified for this but It has worked for me for 40 years.  Get yourself some Nokorode paste flux (Zinc Chloride) at the local hardware store. You don't use it to flux your electronic joints! Just dip your iron tip into it until the solder will wet onto the tip. Wipe the tip on your wet sponge and then solder with good rosin based flux and solder. whenever the tip starts to not wet well give it a dip in the Nokorode again.

Most likely it will be in the plumbing section. Like he said, this is not for electronics soldering (it's designed for plumbing) and acid flux can eat away at the metal if not cleaned properly.

[G7PSK]

It is not the cost of the iron or the solder that makes a good joint it is the person who is doing the soldering, it does not mater how good or bad the equipment is if the operator has not yet got the skills he/she will never get a good solder joint.
A good operator will be able to make sound joint with a six inch nail a piece of lead and some tallow. All good equipment will do is make the task easier.
Before attempting to solder boards it is a good idea to practice soldering pieces of wire together and then move onto laying down solder onto a piece of plain copper clad board write your name with solder. You can feel when the solder is melting and flowing correctly and with practice you should just about be able to solder blindfold.
When placing the tip of your iron on the joint try to get as near as possible right over the joint, if the wire is poking through the board get the tip right up to one side of the wire and as much onto the joint as possible, as they say cleanliness is next to godliness and this applies to soldering especially, clean the iron tip (get one of those brass mop thingies) as well as a sponge, flux the joint even if all you are doing is desoldering as most oxides are refractory in nature and will withstand temperatures far in excess of what the soldering iron can achieve (some oxides will withstand the heat of an arc as all welders can attest)
When I first started to solder all I had was an copper bit on the end of handle and a paraffin blowlamp to heat it I was taught by an old man who knew all the tricks and within half an hour was able to make perfectly good joints on wire and I used it to build my first radio, electronic controlled irons are very nice and make life easy but are by no way essential.
Keep practicing and you will get there without the need to rush out and spend mega bucks on solder and equipment, in fact if you master what you have you will find that when you get a better iron you will that much better and wiser.

[Sigmoid]

The brand of iron I bought seemed relatively unknown but it had decent reviews on Amazon. I took the chance and ordered it over more well known brands such as Weller and Halko because it came with a bunch of tips and other useful accessories.

Trying to learn soldering with a cheap iron may not be the best choice so what would you guys recommend if I were to get a second soldering station?

Well, since you spent $80, you could have gotten this:
http://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU/

I grew up on these things, they (rather, their older counterparts) were the de facto standard soldering iron at all the school activities I attended.
It's far from being the BEST soldering iron you can get, but it's a very decent one.

[Randall W. Lott]

It looks like you tried to dig the pads out!  Solder wick should suck it up without an issue.  You're doing something very wrong or your tip is horrendous.

[Corporate666]

It is not the cost of the iron or the solder that makes a good joint it is the person who is doing the soldering, it does not mater how good or bad the equipment is if the operator has not yet got the skills he/she will never get a good solder joint.

Have to disagree there... if I put a pencil tip in my Metal and try to solder a row of 0.100 screw down terminals on a board with a 2oz copper pour on each of the pads, it's never going to work - the board has a higher ability to suck heat from the joint than the tip->board interface can deliver. 

Same joint with a fat chisel tip and nice iron would be no problem.

In this case, I see lots of copper pours on that board... so if he doesn't have the right tip, it's not going to work no matter what technique he uses.

[0utsider89]

This looks like the job for a Weller Soldering Gun.

[eKretz]

Ahhh!! Kill it with fire!!  LOL 

[G7PSK]

It is not the cost of the iron or the solder that makes a good joint it is the person who is doing the soldering, it does not mater how good or bad the equipment is if the operator has not yet got the skills he/she will never get a good solder joint.

Have to disagree there... if I put a pencil tip in my Metal and try to solder a row of 0.100 screw down terminals on a board with a 2oz copper pour on each of the pads, it's never going to work - the board has a higher ability to suck heat from the joint than the tip->board interface can deliver. 

Same joint with a fat chisel tip and nice iron would be no problem.

In this case, I see lots of copper pours on that board... so if he doesn't have the right tip, it's not going to work no matter what technique he uses.

I mostly use a 60 watt electronically controlled iron for every thing but just today I acme across a job that the expensive iron would not touch simply due to the fact that in order to get rapid heat up and close temperature control the tip has to be light in weight (whatever the tip shape) To do the job I got out my old 25 watt Antex that cost about a tenth of the other iron  as it is not electronically controlled the tip is a largish chunk of copper which stores a lot of heat and will unload that heat in a hurry when required. So it is not the cost of the iron that is important in many cases its the tip weight but it is also the operator that is important if he/she has not the skill to recognise what is going on it is most unlikely that a good joint will be formed and in many ways a simple iron is a lot easier to learn with, no need to worry if the control is set to the right temperature etc and I expect that most people on this forum drive their iron by feel not by this or that temp.setting you only get this feel by practice, you don't learn to ride a bike by learning which gear to use you learn to ride the bike first then you learn to use the gears (quite likely your first bike wont have gear changes) And yes by the fact of what you say you have the soldering skill to recognise that you need to change the tip. But these skills have to be learnt, it is no good spending mega bucks on equipment and material and expecting to make a perfect solder joint but some with the right skills can take the crappiest of irons and the mankiest of solders and flux and still get a passable joint.

[envisionelec]

Even as a beginner, this is pretty bad.  So I'm working on my first real electronics project which involves desoldering a number of components from a PCB and soldering on new ones. I've since realized what some of my mistakes were such as using cheap solder which was also too thick. I'm not sure what went wrong with the desoldering process but getting the solder to become molten so my solder sucker and wick could remove it was very difficult. Eventually I was able to remove all the old solder but not without making a mess of the board. Adding more solder only made it worse.

Right now I'm trying to clean the existing solder off the board but can't get it to melt even when setting my iron to a high temperature. Applying solder wick doesn't absorb it. Maybe all the flux burned off and that's causing it not to melt? What would be the best way to clean up a PCB that's been badly soldered like this?



Thanks for any advice. 

As a former car audio repair person, I see stuff like this ALL the time. It is fixable but it won't be pretty. You need to clean your tip using a Sal Ammoniac block. That will remove the corrosion and other junk. Next, get a quality leaded solder and flux and blob it on to the existing lead-free solder. Be generous. Then using more flux and braided desoldering wick, remove it.

Clean the board up using isopropyl alcohol (even the cheap drugstore stuff works...) or lacquer thinner (preferred!). Install your new parts and scrape away the solder mask from where the pins were connected. Anywhere "upstream" is fine. Using 26 or finer solid, insulated wire, solder the wires to the component and the PCB. This is a simple two layer board and it looks like most of your functional traces are right on the bottom!

Verify that the whole mess works then...

Get out the two-part epoxy and go to town securing the leads in their holes. Don't let epoxy get into the pot(!).  Another option is to place shipping tape on the top of the board, dam the epoxy in the holes and wait for the epoxy to cure. Redrill the holes and replace the pads with a kit (very expensive) or copper tape. I've done all of these successfully, depending on what cosmetics are required.

And don't do that again.

[tszaboo]

If you want to desolder something, first, decide if you need the component afterwards, or not. If not, than cut the component on the top side, if possible and desolder them one by one. If you need it, than you dont want to remove the solder on the bottom side. In fact, you want to solder the three terminals together. After that, all terminals are molten, you can apply some force on the other side of the component an pull it out. Dont force it out with the iron, it will break you tip.
You were using your tip with too much temperature. Anything above 350 degrees could burn your board. First, as envisionelec wrote, you need to clean it. Use tip activator, wet sponge made for this or brass solder tip cleaner.  And for god sake, buy leaded solder. Lead free is completely useless.
Also, if the solder doesnt melt, be patient, and dont increase the temperature. If you have a second iron somewhere, take it, ask someone to help.

[PedroDaGr8]

If you want to desolder something, first, decide if you need the component afterwards, or not. If not, than cut the component on the top side, if possible and desolder them one by one. If you need it, than you dont want to remove the solder on the bottom side. In fact, you want to solder the three terminals together. After that, all terminals are molten, you can apply some force on the other side of the component an pull it out. Dont force it out with the iron, it will break you tip.
You were using your tip with too much temperature. Anything above 350 degrees could burn your board. First, as envisionelec wrote, you need to clean it. Use tip activator, wet sponge made for this or brass solder tip cleaner.  And for god sake, buy leaded solder. Lead free is completely useless.
Also, if the solder doesnt melt, be patient, and dont increase the temperature. If you have a second iron somewhere, take it, ask someone to help.

All excellent advice. A clean tip AND TINNED tip is hugely important. The tip should be bright and shiny with fresh solder on it. Otherwise it doesn't transfer heat as well. I'm sligtly farther along in learning how to solder and recently encountered this as well, possibly. I didn't read this whole thread but I have seen with some lead free solder it forms an oxide coating on the surface which won't melt. A healthy dose of rosin solder and it cleans right up and melts quickly and easily. Using this method and a solder extracter I was successfully able to depopulate an entire old power supply. I got to the point I could desolder most pins in under 1 sec. Heatsink pins took the longest because they often used SO much solder.

[open loop]

Looks you are starting out on soldering and like myself when I started things where not pretty, you just need to practice with the iron you have. BTW the iron you have is way better than the one I had back in 1982 you DO NOT need a new or better iron  just practice and practice some more. I am still practicing even after 30 years

I think that you had the iron at too high a temp and it as already been said that temp is down to feel ( Except on really expensive SMT rework systems). When the temp is too high and you leave the iron switched on the tip oxidises and then in some cases would need a thorough clean and re-tin. When the tip gets really old it is unable to take solder and is pitted and corroded. I have even seen 1mm holes in tips before now.

What I use  to re-tin my tip is a little 1/2oz pot of TTC1 but this seems similar

http://www.digikey.com/product-detail/en/4910-28G/473-1099-ND/1278246

The problem may be that the iron tip is too small and when you apply it to larger area it losses temperature. Also as has been correctly said that the heat is not getting from the tip to joint and if you are using lead free solder then this will make matters worse, try with a rosin cored leaded solder.

If you want to really spend money say 80 dollars then get some IPA ( isopropyl alcohol) and use this to clean you board/s. Some tip cleaner and attach this to your rework station using double sided sticky tape-now it will never get lost. Cut up some 2" cotton squares from an old cotton shirt - you can also buy lint free pads from digikey or similar.Some thin rosin cored leaded solder is probably on your shopping list.

I would also look at chip quick as this is very useful stuff and it is not just for chips. I have used it where I wanted to recycle some connector off a board. I have removed 20 way connectors with before now and this would have bee perfect to remove a two gang pot from the amplifier board you were working on. Dave has done a video check out eppisode #437.

Want another iron? I would recommend a heavier duty cheaper iron as this would be usefull in some cases where you are working on heat sinks etc. something like.

http://www.digikey.com/product-detail/en/WP35/WP35-ND/251718

I have two irons one for SMT and he other is for "heavier" work. The key thing with soldering it is a skill and needs practice, more practice and some more. Been soldering since the 80s and all of my friends think I am amazing at soldering but when I am at work and seen on he shop floor by my colleague Sarah who does soldering every day all day she just shakes her head and says "give that to me and I will do it properly". Trust me there are different levels of good when it comes to soldering.

[dfmischler]

... when I am at work and seen on he shop floor by my colleague Sarah who does soldering every day all day she just shakes her head and says "give that to me and I will do it properly".

I worked (as a bare metal programmer) at a place where most of the technicians had ratings to NASA-STD-8739.3 or the previous standard.  I told them I had been soldering since I was 8 years old.  They laughed and said my soldering still looked like I was 8 years old  .  Actually, I learned a lot from those techs and one said I should go ahead and test for my rating, but I never did.  At this point I don't get enough practice to maintain that level of proficiency.

[jamesb]

FWIW, I too have had good success with desoldering very crappy quality solder by forming a sort of alloy with my leaded solder and then wicking the resulting blob away.