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eBay bargain: Hollow desoldering needles. — Parallax Forums

eBay bargain: Hollow desoldering needles.

GadgetmanGadgetman Posts: 2,436
edited 2013-09-03 21:50 in General Discussion
Hi!

I found these needles and figured that I should share the info.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=370723601236#ht_3548wt_820

These are hollow-tipped needles used for desoldering through-hole components without ruining the PCB.

remove as much solder as possible using normal methods(suction pump and wicks)
Pick a needle that fits the leg of the componentand slide it down as far as it goes.
Apply heat while twisting, until it slips through the hole in the PCB.
Remove needle and admire a thoroughly despoldered pin.

Works best on round pins, though, and the handles are poorly cast plastic, but for $3.44 it's good value for money anyways.
(I have one set, and will be ordering more. These are extremely thin-walled tools so they won't exactly last a lifetime... )

Comments

  • skylightskylight Posts: 1,915
    edited 2013-09-03 03:11
    @ Gadgetman If I have ended up with a filled hole i've applied heat to the pad whilst holding a desoldering pump over the hole from the other side, this has always cleared the hole for me
  • GadgetmanGadgetman Posts: 2,436
    edited 2013-09-03 03:53
    This isn't for 'filled holes', but for removing components that can't easily be attacked from both sides, or with many pins.

    IC Sockets with round pins, the 8x8 LED matrixes, all kinds of weird stuff.
  • Duane C. JohnsonDuane C. Johnson Posts: 955
    edited 2013-09-03 05:26
    Hi Sky
    skylight wrote: »
    @ Gadgetman If I have ended up with a filled hole i've applied heat to the pad whilst holding a desoldering pump over the hole from the other side, this has always cleared the hole for me
    I hate solder suckers!!! Ok, if I really have to I'll use one.
    The likelihood of via damage is high.

    I use home made needles made from 0.021" or 0.024", and other assorted sizes, piano wire. Creatively bend a head and sharpen to a fine point.
    I have NEVER damaged a via with these.

    I was unaware of these thin hollow needle types before. Got to get me some.
    I can see a problem if there is not enough clearance between pin and via though.

    Duane J
  • skylightskylight Posts: 1,915
    edited 2013-09-03 05:39
    Gadgetman wrote: »
    This isn't for 'filled holes', but for removing components that can't easily be attacked from both sides, or with many pins.

    IC Sockets with round pins, the 8x8 LED matrixes, all kinds of weird stuff.
    Apologies I misunderstood
  • skylightskylight Posts: 1,915
    edited 2013-09-03 05:41
    Hi Sky
    I hate solder suckers!!! Ok, if I really have to I'll use one.
    The likelihood of via damage is high.

    I use home made needles made from 0.021" or 0.024", and other assorted sizes, piano wire. Creatively bend a head and sharpen to a fine point.
    I have NEVER damaged a via with these.

    I was unaware of these thin hollow needle types before. Got to get me some.
    I can see a problem if there is not enough clearance between pin and via though.

    Duane J
    Never thought about damage to vias must have been lucky so far.
  • GadgetmanGadgetman Posts: 2,436
    edited 2013-09-03 05:44
    I've never seen them before, either. That's why I bought a set and also mentioned them here.
    I'll try to take a few measurements tonight, and maybe a picture or two.

    That is, if I'm still alive...
    Going to pick up my HP Agilent 16702A logic analyzer today, and that thing weighs 25Kg...
    (Only vehicle I have that's in running condition right now is my bicycle with cargo trailer... Sure, I have a 250W motor in it, but it's still uphill all the way home... )
  • Martin_HMartin_H Posts: 4,051
    edited 2013-09-03 06:36
    Interesting, are there any videos online to illustrate the technique described?

    What I often do is heat the joint up and then give the board a quick knock against a table. The quick deceleration of the board causes the solder to fly out of the hole and onto my work surface. I'll repeat that for all parts of a component until it is mostly free of solder. I have a solder sucker too which I use when there's too much solder for this technique.
  • PublisonPublison Posts: 12,366
    edited 2013-09-03 06:43
    Martin_H wrote: »
    Interesting, are there any videos online to illustrate the technique described?

    What I often do is heat the joint up and then give the board a quick knock against a table. The quick deceleration of the board causes the solder to fly out of the hole and onto my work surface. I'll repeat that for all parts of a component until it is mostly free of solder. I have a solder sucker too which I use when there's too much solder for this technique.

    LOL. That's been my technique for the last 30 years.
  • GadgetmanGadgetman Posts: 2,436
    edited 2013-09-03 13:01
    Can't seem to take a good picture of the desoldering needles, but...
    Outer diameter is:
    0.8mm
    1.0mm
    1.2mm
    1.4mm
    1.6mm
    1.8mm
    2.0mm

    And a bit of prodding gives the inner diamet of the two largest to be 1.5 and 1.7mm respectively.
    For those, the wall thickness seems to be .15mm
    The thinnest feels loose when I try it with a .5mm pin, so the wall thickness can't be any thicker on the thinner needles, either.

    For those who prefer inches:
    1" = 25.4mm
    0.02" = 0.508mm
  • CuriousOneCuriousOne Posts: 931
    edited 2013-09-03 13:13
    The problem is, that solder gets caught in needle, rendering it useless.
  • GadgetmanGadgetman Posts: 2,436
    edited 2013-09-03 21:50
    Yes, eventually...

    As long as you use the needle that is the tightest fit to the pin you're trying to remove from the hole, very little solder will get trapped in it.

    And I suppose that it might be possible to remove at least some of the solder by using a loose-fitting wire.
    (Not going to deliberately fill one and test... )
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