Reusing Solder

Discussion in 'General Electronics Chat' started by johnmorisi, Nov 17, 2014.

  1. johnmorisi

    Thread Starter New Member

    Nov 17, 2014
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    Hey, I'm new to this forum, so I apologize if this belongs in a better suited section. I'm also pretty new to soldering but...

    I recently got a used Volca Beats, analog drum-machine, from my friend. My first thought was that it sounds great and it's very versatile, but the snare drum sound is pretty crap. I looked at some youtube videos, and it turns out a lot of people think this snare sound is crap... such a common thought that somebody decided to make a video on how to mod your Beats with a capacitor. Rumor has it that this capacitor originally belonged on the instrument and there were some manufacturing errors that caused it to go missing on every single 'Beats instrument... including mine. Well, I opened it up, and there it is, labelled C78, two pieces of solder, a white line and no capacitor gapping it. Here's an image for y'all: http://oi58.tinypic.com/30i9c2p.jpg

    Now my question, can I simply just place each leg of the capacitor on the corresponding soldering points and just push down with my needle-tipped soldering iron to solder it in? Or because this solder has been used before, would the connection be less effective? If so, should I just take off this solder and go from there, or do you think placing solder on top of these points would be effective. I'm still waiting for the capacitor to come from Amazon in the mail, its labelled 104 for anyone curious.
     
  2. Brownout

    Well-Known Member

    Jan 10, 2012
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    You'll have more success if you add a little flux to the old solder. Pick some up at your local Radio Shack.
     
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  3. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    For a surface mount like that, you will be fine using the solder mound on the board. Just use a small screw driver to press it down into place, touch the soldering iron to one end and it will drop down slightly. Without releasing pressure, heat the other side and it will drop a bit more. Then heat the other side again to relieve the tension without pressure. The biggest problem you could have is that solder flows under the capacitor and shorts the gap between the mounds of solder.

    Do it right and you'll be done in 30 seconds. Plan, know what you will do and don't try to make it look perfect. A connection is all you need.
     
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  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    This should definitely work, but you can also run into some problems:

    The solder on the board is lead free and your iron can't melt it.

    You press down on your cap and break it in two.

    You press down on your cap and break it somewhere in the middle you can't see.

    You make a little mess and short to another part, and then...


    Since you have an iron I'll assume you've used it already. For this I would make a little larger blob of frech solder on one of the pads. The using tweezers hold the cap to the blob and reheat.

    Now with the cap stuck there put your iron and solder to the other side and flow that too. It may not look "professional," but if I was doing it I'd first remove the existing solder with a magical device I own (called solder wick with flux).

    Good luck and welcome to the forums!
     
  5. DerStrom8

    Well-Known Member

    Feb 20, 2011
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    Brownout is right, you'll definitely want some flux. The chances that the contacts are at least somewhat oxidized are quite high, which means resoldering could produce a very poor joint. Personally I'd recommend very fine rosin-core solder to redo the job. I never recommend reusing old solder.
     
  6. johnmorisi

    Thread Starter New Member

    Nov 17, 2014
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    Thanks a lot guys. I am pretty new to this, so the thought of adding solder in such a small area gives me a little bit of a scare, I've only soldered wires to areas with much more room for error. I've never ran into any problems of shorting gaps though. If something like that happened, wouldn't I be able to fix it by removing the overflow, or is that a lot harder than it sounds? Also, if I happened to overlook some overflow and I short it, what kind of effect do you think that would have on the device if I turn it on? Will it go mad http://giphy.com/gifs/movie-film-horror-dZJKiSR7mMxSE/fullscreen ? and maybe have permanent damage?

    In other demonstration videos of this, people have just touched the capacitor to those spots by hand and you can hear the difference almost immediately, so I think all it would need is a very small connection.
     
  7. johnmorisi

    Thread Starter New Member

    Nov 17, 2014
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    I probably should've mentioned that the capacitor that I'm using is relatively big: http://www.alibaba.com/product-detail/50V-0-1uf-disc-RADIAL-Ceramic_505898594/showimage.html so i just gotta get those two legs touching each soldering point... so solder flowing under this is not that big of an issue I dont think.
     
  8. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    You could have also gone to RadioShack and picked one up for 1.79.
     
  9. johnmorisi

    Thread Starter New Member

    Nov 17, 2014
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    Yeah... but the bus there is $2, plus 3 hours out of my day that I don't really have to spare. also I had to get a few things off amazon too. meh, dont ridicule me!

    but thankyou for your advice, it didn't mean to come off snotty
     
  10. takao21203

    Distinguished Member

    Apr 28, 2012
    3,577
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    Its very easy with a broad tip you can just move off bridges, soldering almost like drawing with a pen. 1mm or 0.8mm solder is just fine and it contains flux already. 0805 parts arent all to easy however, I'd not recommend a point tip, since you cant remove solder with it.
     
  11. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    You do realize that you probably want to cut those legs down significantly? Normally, they would go through the board so that the disk is resting on the PCB and all the excess leg material on the back is cut off.
    TH Components.png
     
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