One of the first tools that is added to a toolbox when working on electronics, perhaps besides a multimeter, is a soldering iron. From there, soldering tools can be added as needed such as a hot air gun, reflow oven, soldering gun, or desoldering pump. But often a soldering iron is all that’s needed even for some specialized tasks as [Mr SolderFix] demonstrates.
This specific technique involves removing a large connector from a PCB. Typically either a heat gun would be used, which might damage the PCB, or a tedious process involving a desoldering tool or braided wick might be tried. But with just a soldering iron, a few pieces of wire can be soldered around each of the pins to create a massive solder blob which connects all the pins of the connector to this wire. With everything connected to solder and wire, the soldering iron is simply pressed into this amalgamation and the connector will fall right out of the board, and the wire can simply be dropped away from the PCB along with most of the solder.
There is some cleanup work to do afterwards, especially removing excess solder in the holes in the PCB, but it’s nothing a little wick and effort can’t take care of. Compared to other methods which might require specialized tools or a lot more time, this is quite the technique to add to one’s soldering repertoire. For some more advanced desoldering techniques, take a look at this method for saving PCBs from some thermal stresses.
Thanks to [Filip] for the tip!
30 thoughts on “Finessing A Soldering Iron To Remove Large Connectors”
This is were the desolder needles come in: heat a single pin, push the stainless steel needle over the pin though the pcb, rinse and repeat.
Protip: buy several boxes as the thinner ones for dil packages don’t have a long life.
Very clever. Makes perfect sense really
Of course if you do this with a stranded wire it might soak up more solder. But then give reinvented soldering wick.
/give/you’ve/ …. Can I blame auto-defect?
I use a solder pot for removal of things like that. Cant ever damage a board while doing rework- ever
Or there’s low-temp solder.
Thats the trick, yeah.
Only caveat, you need a decent soldering iron with the ability to put enough heat into all that mass and a wide enough tip to transfer it.
I was going to say that.
That’s a single use hacked up woodworkers iron to my eyes. Clumsy hands could make the same tool look bad. We take temp control for granted.
Won’t be my first or last ‘custom’ cheap iron. Got one to solder around corners.
Not just enough power to keep the whole blob molten, but enough to heat it rapidly enough to avoid the same board damage as you’d risk with hot-air rework.
I use a mix of a Hakko FR-300 and a “scoop tip” to remove things.
The FR-300 is self explanatory, its just a vacuum with a soldering iron on it. Put it over the pin, pull the trigger, and wiggle it around a bit. Then move to the next pin.
The scoop tip is a secret I wish more people would know about. Its basically a bevel tip, but has a “scoop” milled out of the bevel. When tinned properly and clean, pressing the scoop near a weld will often “suck” blobs of solder up into it. You can also fill the tip with solder, and then drag-solder. Great for doing surface-mount chips, without having to use solder paste.
I bought one for my iron ages ago, but can’t find em again.
The Hakko FR-300 is the best $300 I’ve ever spent on a tool.
Do you have any link to the “scoop tip” please?
Hakko has a couple of beveled tips with a dimple. Google “Hakko BCM2|BCM3”.
I know it as a “reservoir tip”. I wish they were more popular and readily available, and I think they would be if more folks knew about them and got a chance to work with them. They are indeed the cat’s meow for drag soldering, but I never knew about their desoldering capability. Thanks for the ‘tip’ – pun intended!
I been soldering for 20+ years . What you done was downright like feeding a chicken after you cooked it. A little bit of flux the right beveled tip and a solder sucker would take that off the board in a quarter of the time and none of the mess you just made . Please don’t make tutorials showing people how to do it the most wrong way there is .
Exactly so. Literally every other way to do this — and there many — is faster, more efficient, and uses less energy. This is the worst way to do this.
I’ve been soldering for 50+ years, and have experienced many situations where your method doesn’t work. Sometimes the hole size vs pin size, and/or the accuracy of the match between the pin grid of the connector and the hole grid on the board, and/or pins having been bent a bit when the solder was applied, can make removal a real SOB. Even a really good solder sucker, lots of flux, the right solder, and the addition of wick can leave some pins stuck. I can often free them with sideways pressure applied with the tip of the iron, but this sometimes damages the through-plating.
The best solution is a good solder removal gun that allows you to wiggle the pin while sucking the solder out; but if you don’t have one, then you do what’s needed to remove the part. Sometimes that turns out to be a big back-and-forth drag-soldering exercise that risks damaging pads, traces, components, etc. And I wouldn’t want to try that with the connector shown in the video, except put of desperation. The video shows an inventive and potentially useful technique – I’m happy to know about it and will use it if ‘kinder’ alternatives either aren’t available to me or don’t work for reasons mentioned above.
The hard part is the “sliding it off” at the end after it’s all fluid. Not easy to do this method unless what you’re desoldering is on the edge of the PCB.
You can just turn it upside down. Reheat if needed.
I’ve used a Weller soldering gun in the past for this purpose – being cheap, I would use #12 or #14 solid copper wire salvaged from [USA] household wiring projects for the tip, instead of the expensive Weller tips. I would bend the end of the wire in a shape appropriate to cover the pins [instead of the simple loop used for soldering. The soldering gun had enough power [60/100W] to heat the pins quickly. I would then [in my pre-soldering wick days heat each pad from one side with a normal iron, and use ‘inertial transfer’ [tap the board against the table] to remove solder from the pad’s hole.
I recall seeing DIP desoldering tips for high wattage irons in the distant past, back when they also sold GOLD plated Ungar soldering iron tips. A shipper “lost” the latter (along with the other items in the electronics tool box) in a move otherwise I’d still have them. Talk about holding a tin and lasting forever… which is probably why, more than about the price of gold, they got rid of them. You can find them on eBay at times, like now: Ungar Brand Item# 6313 Iron Clad Gold Plated 24kt Replacement Soldering Tip.
I have a spare soldering pen at work that has the “tip” for a DIP, but that was used a long time ago. I converted a heated hollow tip spring release piston de-soldering tool to have a foot power suction bellows. It’s much faster than that single shot and reload stuff. Now I have single hand repeatable action. The capture handle gets hot doing a lot of pins in one session.
At home and at work a trusty Weller 100/140W resides in a holster attached right at hand under the edge of the bench. Quick to draw and hit a little spot anyone where anyone else would have to wait and heat up an iron. Boards with thick cold joints at plug-in pins and power transistors get shot at where an iron will take too long because of the thermal mass at each pin.
Of course I use 10 or less often 12 gage wire in my gun. Pro gun when it comes to soldering especially on tubes and terminals gear. Lots of repair on older stuff is just refluxing and it’s good to go.
There is a point where the torch, or the butane lighter, needs to come out. I have enjoyed considerable success with a $5 gas station butane lighter in just such applications, especially on older equipment with excessive soldering.
Greetings, I am a high school student and I need a angle sensor to measure incline angle. I used a Tilt sensor for Raspberry Pi but it is too sensitive and I do not have a luck using it in my project. I came across BerryIMU but it is not in the US. What else can I use? My project is to measure an angle of a person when that person bends foreword towards the screen/monitor. Any help is appreciated.
Paint the person black and white checkerboard than use image processing.
What exactly is a person’s ‘incline angle’? Body kinematics are complicated.
Might I suggest the gyro chipset in the phone the person already has. Write an app that talks to the rest of your project. Ask them to carry the phone in a shirt pocket or their bra/cleavage for the duration. Have app grab pics.
When I was your age, I was busy putting subliminal ‘you should fuck HaHa’ messages onto the girls computer screens. The rest of my time, I wasted. Girls didn’t get enough screen time back then. Also tricky, could go awry if the wrong person was exposed (coach Buzzcut?). Bugs also hazard fraught.
Your problem will be defining the reference datum angle for the person. Everyone is different. It may be better to create a fixed seating position and monitor, and measuring the separation between the nominal, calibrated-per-person, “resting” position and the face of the monitor with a rangefinding device or with video records from the side and a graduated background like Mythbusters used to do in many of their investigations. Derive the angle from those data points.
That works in a pinch, but if one can afford it, something such as a Hakko FR-301 shines, even with the extra time spent cleaning it afterwords. Of course, be sure to still have some wick and a manual sucker for the odd-shaped pins that you may not have a nozzle for (or don’t want to spend the extra $ for a nozzle for an odd-shaped pin you only remove occasionally.)
My personal choice when I don’t care about the part I am removing is destroying it completely so that only small parts of it still remain attached and patiently removing the rest with a normal soldering iron. It works best most of the time. Also the mobile phone SMD tip for the hakki clone I have also helps ease the process. The method mentioned is best if one wants the part to remain intact. But like someone else told, the solder pot is best wrt ease.
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