Best way to desolder a transformer?

[braeden]

Hello,
Without correctly installing the mu-metal shields on my OEP transformers for a G9 project I'm doing at the moment, I soldered all of the transformers onto the board, only for the shield's base plate to fall off a few minutes after. What's the best way to desolder these transformers? They were a pain in the ass to get in and I don't see myself solder sucking these transformers out anytime soon. I'm also being very cautious about the pads on the PCB as well.

Ideas? I'm stuck otherwise!

Thanks!

 

[zebra50]

They were a pain in the ass to get in and I don't see myself solder sucking these transformers out anytime soon.

I'm surprised to hear that! I swapped mine from OEP to Lundahl and I don't recall any problems getting these in or out again with just a sucker and a bit of brute force.

Which boards are you using?

 

[peter purpose]

Heat gun, or blowtorch..... be super gentle.

 

[gyraf]

..you can get a long way by just putting on the top cover of the mu-metal shield, perhaps holding it into place with a drop of glue.

I'd try this first and see if results (hum levels) are good enough - desoldering OEP's is quite complicated, and the pins are easily pulled out (and transformer thus dead)

Jakob E.

 

[Rob Flinn]

Buy yourself a Hakko 808.

 

[braeden]

Thanks guys, I think the only option for me is to buy a desoldering gun. Expensive but I think it will come in handy.

I'll see how it goes!

 

[Kingston]

Just hold on there a second! Don't run to the shop to get an expensive desoldering gun just yet.

Because there's solder wick. I have yet to see a desoldering gun that is as flexible and reliable.

Just make sure it's the kind of wick with rosin infused and it will suck the solder right out. That plain copper wick is pure bullsh*t I just don't see the point.

$2 wick vs. $400 desoldering gun. hmm.

 

[zayance]

I have yet to see a desoldering gun that is as flexible and reliable.

I have this, reliable?, will see, the price is nice tough and it's been used quite often now, and still no prob, it's big tough...
Recommended for hobby use i think , better go for the real thing if it's on daily basis...
But as for the filters and all, it's maybe better to get the Hakko ones, used in the 808, they are the same here..
the Aoyue ones are ok, but maybe not as good in time..

I achieved good results with solder pump for quite some time, but it needs skills, as you can damage the board easily

http://www.aoyue.de/product_info.php/info/p2960_Station-de-dessoudage-AOYUE-474A-.html

 

[Kingston]

I achieved good results with solder pump for quite some time, but it needs skills, as you can damage the board easily

I've never gotten any use out of solder pumps. They just suck out the major portion of the blob, and still leave the part firmly attached. Then when you think it's completely desoldered you end up ripping out the whole via! I would say avoid in all situations.

Solder wick will remove the whole thing.

 

[zayance]

Yes true, but if you go fast then it works at least for me, i usually have the pomp really close to the solder tip,
and when melted just move the pump on top and Boom, gnd pads could be a Pita tough...
I used Solder wick as well, and remember adding a drop of thin to it before,
it helped the succion process....., but again, i think both methods need some practice
and so if it's the first time, it could be first disaster imho....
Better practice on some other boards before, to get the idea and figure out your own method...

 

[Kingston]

I used Solder wick as well, and remember adding a drop of thin to it before,
it helped the succion process.

Yeah it helps because the tin conducts heat better when the iron tip touches it. If you really want a super suction for serious problems spots add extra rosin there, and on the target area as well (the same stuff used on SMD work). Then the solder will be GONE. You can see it travel up the wick quite far.

 

[zayance]

All solder wick are not good tough, i remember using a no clean one (First Braid NT) 2mm one
the wick is tightly made, which one are you using Kingston?

 

[Kingston]

It's called Chem-Wick or Soder-wick:

http://www.partco.biz/verkkokauppa/index.php?cPath=2072_1908

All wicks that have rosin infusion will work. I guess the one you used has no rosin, the copper braid tightness should have no effect. It will simply not suck at all if there is no rosin. I don't know why they even sell that stuff.

 

[zayance]

Well now you have all sorts of working options to choose from braeder,good luck!

 

[braeden]

I didn't end up using the solder wick, I bought a $180 ( :'( ) desoldering gun from Rhino Tools in Australia. It works great, albeit one of the pads has half disappeared, but I am sure that was a result of my previous brute-force style desoldering efforts ???

So glad that I finally got these damn audio transformers off!

Thanks everyone!

 

[soundcollage]

+1 for the 808. Make sure you get a tip size that the lead can fit into so you can wiggle it a bit when applying suction (insert joke here). I find its good to add a little fresh solder with a regular iron first, especially if you are repairing an ancient board. I have tried every solder sucker type and nothing beats it. Rosin wick works ok for single sided boards but i could never get it to clean out plated through holes. Make sure you clean it after each use though or cleaning it becomes a pain. I also recommend the pin vise and appropriately sized bit for the tip that is offered as an accessory to it, which cuts down headaches when you aren't as diligent at cleaning it as you should be.
(oops realized I was too late as you found your solution)

 

[pucho812]

hand held  none electric de-solder pumps and wick are rubbish. You stand a greater chance of destroying traces and over all causing more problems using those.  If you plan on doing much repair work, a desolder station is the way to go. here is a inexpensive desoldering station by xytronics.


http://www.howardelectronics.com/xytronic/988d.html