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buserror

Trick to desolder thru holes?

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I've desoldered my thru hole caps, but the hole is now 'full' and no amount of heat and manual desoldering pump seems to help. Do I have to re-drill the center with one of these tiny bits? Seems some of the holes are straight onto a power plane, so they act as heatsink...

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Try adding some fresh solder and a bit of flux when heating it up for removal. Braid may also prove helpful. 

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8 minutes ago, dzog said:

Try adding some fresh solder and a bit of flux when heating it up for removal. Braid may also prove helpful. 

Thanks, I do try all of these, add solder, add flux, use 400C on the iron etc etc not much luck. Well i cleared about 2/3 of them using various combination of these, but some are just... tough!

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On 5/22/2020 at 11:28 AM, buserror said:

Thanks, I do try all of these, add solder, add flux, use 400C on the iron etc etc not much luck. Well i cleared about 2/3 of them using various combination of these, but some are just... tough!

I have an 858D clone hot air gun that I use in conjunction with the iron when I have to deal with a ground plane soaking heat up. If the iron isn’t enough, usually adding the hot air will provide enough heat to clear things out. In my experience, copper wick will just soak up even more heat, which is a problem if the ground plane is posing an issue on its own.

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1 minute ago, Michael_b said:

I have an 858D clone hot air gun that I use in conjunction with the iron when I have to deal with a ground plane soaking heat up. If the iron isn’t enough, usually adding the hot air will provide enough heat to clear things out. In my experience, copper wick will just soak up even more heat, which is a problem if the ground plane is posing an issue on its own.

Ah good tip, in fact, excellent idea! I also have hot air so I'll try that next. I've been sulking for a day or so because of that problem so it gives me "options" :-)

 

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I've managed to clear stubborn thru-holes by using a bare piece of solid CAT5 wire. Heat up the thru-hole with hot air, cut a wire out of the cable several inches long, strip it, and pull it straight through. It's helped me get thru-holes clean enough where I can stick other components in.

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Old thread, but I figured I would chip in with some info. I've just gotten a set of "desoldering needles" from AliExpress. They're basically stainless steel needles that you put into the heated-up joint and solder won't stick to them. They clear holes fairly well, although I've only needed to use the smallest one and the plastic handle is getting a little melty from heat over time.

 

https://www.aliexpress.com/item/32848142453.html

 

Lots of vendors for these, so please shop around.

Edited by ravuya

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8 hours ago, ravuya said:

Old thread, but I figured I would chip in with some info. I've just gotten a set of "desoldering needles" from AliExpress. They're basically stainless steel needles that you put into the heated-up joint and solder won't stick to them. They clear holes fairly well, although I've only needed to use the smallest one and the plastic handle is getting a little melty from heat over time.

 

https://www.aliexpress.com/item/32848142453.html

 

Lots of vendors for these, so please shop around.

Interesting! Just bought a set to try. 

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Decent wick (gootwick from Japan), leaded solder and flux. I use Amtech 223. For individual through-holes, it might be advantageous to invest in a desoldering station like the ZD-915. 

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I think I'm gonna love those needles! :approve:

 

 

I have several 030 PDS connectors to remove, Now I can probably use a side cutting wheel on the drill press to remove the connectors a couple of mm off the PCB and easily do each pin individually! Can cleaning up the pads with wick refill the thruholes with old solder? If so, I'd imagine that would be easily removed using this method. Many thanks!

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Happy to help. It definitely made a recent job (Famicom AV board) go a lot smoother since I could just push old wires out of the holes. Since they were an impulse buy, it did take me a few months before I figured out this is what they were really good at.

 

Usually in my experience cleaning things with wick (as long as you have enough flux on the wick) makes solder not stick into the holes. The wick grabs it up too fast, like brushing a paper napkin over a soap bubble blower wand if that makes sense.

Edited by ravuya

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On 8/16/2020 at 5:49 PM, archer174 said:

Interesting! Just bought a set to try. 

Aliexpress doesn't take paypal so I ordered a set from ebay to test.

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I've had good luck with my Hakko FR-301. I used an old bulb-style Radio Shack desoldering iron for over a decade that worked, but tended to leave solder in the holes like you mention. The FR-301 can blast through a whole PDS connector in no time and leave the holes squeaky clean. It can bog down with a large ground plane but in that case bumping the setting up one step usually does the trick. There's probably clones if the cost is too high.

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