Desoldering

Discussion in 'General Electronics Chat' started by Firestorm, Jan 27, 2005.

  1. Firestorm

    Thread Starter Senior Member

    Jan 24, 2005
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    0
    well i guess i can use a soldering iron without any flux to get the caps and resistors off a couple chips i have that i dont use
    ive found the stuff on them is qute common and some hard to find and want to make use of them...
    will my idea work? if not or maybe it does, is there a better way?
    Any desoldering ans soldering info would help alot...
    thx
     
  2. jcinci1

    New Member

    Jan 27, 2005
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    0
    just add regular solder while you desolder components, it has flux in it.. and remember not to get the component too hot while unsoldering
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    I imagine you mean printed circuit boards, rather than chips.

    You really want to use a wet soldering iron to remove components. Solder and flux on the iron makes the heat flow faster, so less damage is likely to occur.

    The crudest effective solder removal technique is to heat one joint and immediately bang the board against the table top such that the solder flies off from inertia. Don't use the dining room table.

    Or you can get a solder sucker to literally slurp up the liquid solder. The come in bulb and piston types, and work well for a period of time. They are good for large joints.

    Best is to use a braided copper wire, known as solder wick od desoldering braid. Placed between the joint and the iron, it wiks the liquid solder away fron the work. It requires a wet iron to work.

    Whichever technique you use, be sure to wiggle the lead with pliers to make sure it's unstuck before trying to pull the component - tearing the lead off because you're prying with a screwdriver is a dead loss.
     
  4. Firestorm

    Thread Starter Senior Member

    Jan 24, 2005
    353
    0
    k thx for the info, i found some wick at Radioshack and plan on getting it and a heatsink...still have a couple questions though...wut do you mean by a wet iron and if i just use the wet iron( which im still trying to figure out) and solder to remove it, do i just stick the solder to the joint like im soldering it until it all gets liquidy? then pull it off?
    thx 4 the help...

    -fire
     
  5. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
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    Hi,

    By wet iron, I mean that the tip has been touched to solder so it is covered by a film of liquid metal. A clean dry tip will not transfer heat very efficiently.

    Using wick, you place the wick on the joint to clear, and press the soldering iron tip against it so as to heat the joint. The liquified solder from the joint will flow into the braid. You'll see when it gets saturated and has to be moved to a clean section to keep wixking.
     
  6. lykanthropus

    New Member

    Feb 18, 2005
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    Keeping a fresh thin film of wet solder on the tip will also make the tip last longer and keep it from overheating. Basically, you should not solder with a dry tip. If you solder with a dry tip the solder tends to push away from the tip making it difficult to control and the tip will start to oxidize and become corroded.

    I would also like to suggest not buying the crappy starter iron that radio shack sells for ~$10. Spend a few more dollars ($30-50)on a Wellar with the screwable replaceable heating element, and 3 prong plug for safety. There are several more tip varieties to choose from and they screw on easily instead of having a side screw. Be careful using the skinny tips (for soldering integrated circuits)on the nonadjustable higher wattage irons since the tip may disfigure from overheating. You can use a 25Watt with a skinny tip(IC's and smd components) or 33W with conical tip (standard through hole) and 50W for larger surface area soldering and then 100W for soldering large gauge wire to terminals like 8awg. You could spend a few dollars more for an adjustable soldering iron as well but i have found that just having the right size tip in a certain wattage iron works just as well.
     
  7. atferrari

    AAC Fanatic!

    Jan 6, 2004
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