Desoldering help and where to buy

[rmeldo]

Hi,

I changed my mind and I now want to remove a 10 pin header which I soldered on a PCB and I am trying to understand what is the best way to desolder.

I heard of low temperature solder and I found a link, but the prices are very high. Has anyone else found cheaper elsewhere? It seems so expensive.... is there a specific reason for that?

I would like to buy some to try.

An alternative is the copper wick, which I have already bought but not tried yet.


Help would be appreciated.

Thanks

Riccardo

 

[hippy]

Cut the header down to individual pins by removing any plastic surround and pin joins if possible. That lets you take it out a pin at a time which is much easier than all in one go.

 

[BeanieBots]

There was quite a long thread a while back on de-soldering methods.
Worth having a search, there were some good tips.

Personally I prefer to use a solder sucker. I don't like using wick but that's a personal preference. Have salvaged many 40 pin chips using a solder sucker and re-used them afterwards.

 

[rmeldo]

Thanks to both.

Is the integrated solder-sucker sold by Maplin much better than using two separate tools?

 

[BeanieBots]

I've only ever used seperates so cannot comment.
What I can say, is that the sucker needs to be a good one with replaceable tips. If it's not a fast sharp suck, it won't do the job.

 

[Andrew Cowan]

If you have a heatgun, you can try heating the whole thing up (from the solder side), and pulling off the header with pliers. This may damage the PCB.

Alternativly, cut the header into individual sections (or blocks of two), and pull out. This will damage the header.

Or get a solder sucker (the ones with a built in heater are best), and you may be albe to save the lot.

A

 

[George Sephton]

Ive survived without a solder sucker, mine broke. I had to de solder some 20 odd pins at once adnd did Andrew's method. Use a heat gun heating up a few pins at a time, (you can do this method with a soldering iron but it's longer) then hit the pcb againt a side, or ground and all the solder will fall to the floor and solidify, shouldn't stick, then do this until barely any solder is left, give all the pins a heat then pull them out with a pliers or tweezer but the plastic may melt. Try what you can, I de-solder like that its a good method.

P.S: this often requires two people, one to hold the pcb and heat it another to pull them out.

 

[Andrew Cowan]

P.S: this often requires two people, one to hold the pcb and heat it another to pull them out. Or a vice.

Using a heat gun is great, and works for all (uncrimped) components (especially SMD). However, you can burn the PCB if you are not careful.

A

 

[kevrus]

Heat gun, never thought of that...i've had good success with a decent solder sucker.
I find that if for any reason, the 'suck' was unsuccessful, it's easier to re-solder the joint and then try again rather than keeping the iron on the joint and trying to remove that last little bit of solder...works well for plated through holes

 

[Andrew Cowan]

And with the heat gun - watch for solder spray. (Wear gloves if holding the PCB).

A

 

[Janne]

I've tried the heatgun to remove componponents 2 times, the first and the last.. it was with my first "real "picaxe project. I salvaged the IC holder off for the 18x from an old pcb with the heat gun, and it was no good. The reset pin, for example would leak down to 2 volts, even when I had an 500 ohm resistor for pull-up! You can only imagine the frustration when i found the cause for all the odd problems after an evening of troubleshooting...

I guess the heat gun damaged the holder beyond being usable. Might work for some components, but I won't be trying it again.

 

[Dippy]

Oh dear.

Just like lager, 'heat guns' are not all the same.
Just like lager, some are more powerful than others.
And just like lager, you sometimes need to get used to it.
And always practice on duff stuff first.

Personally, I wouldn't use a hot air gun. Fine for plumbers, but not enough control and heat is indiscriminate. But for stripping Grandad's old Radiogramme boards then its probably OK after a bit of practice.

Be wary of overheating PCBs if you are simply replacing a component on a PCB. Overdoing it can separate the copper from the base.
Especially cheap crappy PCB.

For most stuff, most people use an iron and sucker as mentioned. Some prefer wick(braid). Its a personal thing. Stan uses his beard with a bit of flux - you may think his beard is grey, but in fact it is solder splat

I find suckers poor for quick desoldering on double-sided boards for anything with a lot of legs - as solder wicks up the pth.

I haven't tried the Maplin desoldering thing. I think CPC do a cheapy desoldering electric pump thing too.
In the past I have used proper (expensive) desolder stations, but they're too expensive for casual hobby work.

My suggestion: part with a whole massive fiver and buy a sucker and some wick/braid and give it a go.

But, AGAIN, there are suckers and suckers. Some are wimpy, some could suck a golf ball up a hose pipe. But ones with huge springs have recoil, which is quite a laugh with smd. Motorised pump ones don't and the benefits are noticeable.


Alternatively, use a heat gun method over your Mum's £80/ metre Axminster carpet and she'll soon buy you a desoldering station.

Like BB says, this was covered in great detail a while ago, so have a search.

 

[Ralpht]

Solder Wick is only useful to remove components from single sided boards and for cleaning up.

The cheapo de-sucker thingy's that are spring loaded - you 'gets what you pays' for and even then, no guarantee. They probably will work on a single sided board, don't even bother on a double sided board. Unless the double sided board is not thru-hole plated.

A double sided board most likely will be thru-hole plated. That means that solder is all the way through the plating and on both sides. I've had years of experience with solder re-working and have never found solder wick or the spring loader sucker thingy's to work on these boards.

(They are called suckers because only suckers will buy them) I just had to put that in - Sorry!

Assuming you don't want to destroy the board and/or the components, a heat gun is not a good approach but can yield fair results with a lot of care and luck - and very good control of where you put the heat.

A re-work station is the only real viable option for double sided thru-hole work. Yes it's expensive beacuse of the vacuum pump and special iron and tips. But it will work every time.

Good luck, you may get away with using the other methods presented above.

Low temp solder will have no real effect on removing a component that has already been put in using normal solder. It can assist by not needing as much heat to remove a component, only if the component was original soldered in using low temp materials.

 

[KIGX]

I can never get wick to work and the spring-loaded suckers just bounce around too much. If you have money to burn a real desoldering gun with a built-in vacuum pump is wonderful. They will suck the hole clean. A friend of mine has one and he removes header strips, ICs, all kinds of many-legged things with no problem. You're probably talking US$100-200 though. Best thing is to find a friend who has one...