[sdiy] solder wick?

[Gene Stopp]

This is one of them things that has mutliple ways of doin it... funny you
should mention exactly the way that I came up with long long ago way before
marriage and kids when I actually spent time gathering wages sitting near
soldering irons...

I'd use pair of "electronics cutters" - I'm sure they have a *real* name,
which I never bothered to learn. Anyway they have physically small jaws and
you can come in from above on a standard DIP chip and cut a single pin right
at the "shoulder". Go around the chip and cut all the pins, and the chip
will fall out leaving all the pins. Then you just touch them with the tip of
an iron, and they will stick to it and pull away from the board
effortlessly. I think they are so small they heat up instantly, and there's
a tiny bit of magnetism on a WTCPS station tip, so the pad never even gets
hot. The pins just drop out like magic.

This leaves you with a bunch of clean pads filled in with solder. At another
company long long ago we had these big pedal-controlled air-powered sucker
irons with little glass traps on them, and they worked great even though
they were pretty loud. Sounded like a tire shop. And you could only get on
them during break time or lunch when the rework girls were away. So usually
I was stuck with a spring-powered sucker, so I got good at those. The white
heat-resistant tip would get a little gouge in it from the iron tip, and you
could use this as an advantage to get a good air seal on the pad with the
iron tip still sticking through and touching it.

Bulb suckers, same thing, less recoil, not as strong a suction, but they'll
get you by. Not good if you plan to do a lot of pins.

I find that solder wick kills pads and traces (but then that just may be
me). It's really only useful for places where solder is really blobbed up,
like panel component terminals or high-power components. It's not very good
on DIP-populated circuit boards.

One thing that is really neat for removing parts whole is a solder pot. Good
example - I used to have all the circuit boards from a 360 Systems Digital
Keyboard. Loads of good parts - CEM3360's, nice trimpots, TL082's by the
dozens. With a solder pot I stocked up my parts drawers in a matter of
minutes. This ruins the circuit board. The fiberglass starts to come apart.
Solder pots are also fun for experiments with molten metal when the boss
isn't around.

So - if you care about the circuit board, but wanna trash the chip, use the
pin-cut method (like Jim says)

If you care about the part but wanna trash the circuit board, use a solder
pot.

If it's a DIP chip and you want to keep it and the circuit board too, a
powered sucker is best. You can use a manual sucker but be prepared to
repair some pads with jumpers.

If it's not a chip, a manual sucker should be OK.

If it's a big part, solder wick may work, but it's a judgement call.

Of course all this only applies while through-hole parts are still in use...

- Gene



-----Original Message-----
From: patchell [mailto:patchell at silcom.com]
Sent: Friday, February 28, 2003 4:45 PM
To: Stephen Begin
Cc: synth
Subject: Re: [sdiy] solder wick?


    Here is how I unsolder stuff....

    Step 1:
        Get a pair of diagonal cutters and remove the part from the board by
clipping it out.
    Step 2:
        Use a soldering iron to remove the leads from the holes using either
a
pair of tweezers or pliers.
    Step 3:
        Use a cheap desolder pump to clean out the holes..

    I have found that this methode, at least for me, is the least
destructive
way of removing parts from the PC board...although, I realize, if you are
trying to remove a part intact, this will not work.


Stephen Begin wrote:

> I've got a couple questions about desoldering
> Does anybody use the "no-clean" type of solder wick?
> What do you use to clean up the mess from normal solder wick?
> Is a cheap desoldering station worth having, or is it pointless unless you
> are willing to get a good one?
>
> Basically I'd like to hear anything people have learned about desoldering
> from experience.

--
 -Jim
------------------------------------------------
* Visit:http://www.silcom.com/~patchell/
*-----------------------------------------------
* Come to the Pacific Southwest DIY Meet
* April 12, 2003 10am-5pm
* Santa Barbara, CA
* http://www.silcom.com/~patchell/synthdiymeet.html
* for details
*-----------------------------------------------