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K3 mods and methods: smt resistor/capacitor de-soldering

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David Windisch

K3 mods and methods: smt resistor/capacitor de-soldering

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Brgds,
Dave, N3HE
Cincinnati OH

Bob Naumann W5OV

Re: K3 mods and methods: smt resistor/capacitor de-soldering

I find that the key to removing SMT components like those involved in the
mods described is best done with solder-wick and quick movement of one
small-tipped iron to both ends of the component. I removed most of the
solder with the solder-wick and then alternate heating of both ends of the
component until it lifts up from one end. It then becomes a matter of
heating the remaining end and plucking the old part off with the iron's tip.
Then, clean the pads with the solder wick and install the new component.

Being able to see is crucial, and loads of task lighting is helpful.

73,

Bob W5OV

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Don Wilhelm-4

Re: K3 mods and methods: smt resistor/capacitor de-soldering

Bob,

I have been successful using that technique, but when there is any
difficulty with the solder re-attaching, I slide a THIN knife blade
under the first side when the solder melts. The blade must be thin (and
must have a sharp edge) so the amount of lift is very small - a thick
blade could pull the pad that is still soldered to the board.

73,
Don W3FPR

Bob Naumann wrote:

> I find that the key to removing SMT components like those involved in the
> mods described is best done with solder-wick and quick movement of one
> small-tipped iron to both ends of the component. I removed most of the
> solder with the solder-wick and then alternate heating of both ends of the
> component until it lifts up from one end. It then becomes a matter of
> heating the remaining end and plucking the old part off with the iron's tip.
> Then, clean the pads with the solder wick and install the new component.
>
> Being able to see is crucial, and loads of task lighting is helpful.
>
> 73,
>
> Bob W5OV
>
>

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gm3sek

Re: K3 mods and methods: smt resistor/capacitor de-soldering

In reply to this post by David Windisch

David Windisch wrote:

>
>It's a process, it's easier than you think, and there is plenty of room
>for creativity. I don't pretend to know it all; this works for me.
>
>BASICS:
>
>Light up the work area.
>
>Get comfortable seating.
>
>Buy a pull-down magnifier. Don't skimp here. I use OPTI-VISOR, 3X
>lenses. Buy 2 of the physically-smallest low-power soldering pencils.
>Buy a *large* decorative clothes pin. Buy various-length,
>variously-shaped stainless tweezers.
>
>Attach the pencils to the clothes pin. Hose-clamps? Shim the jaws open
>so the pencil-tips get proper spacing to (just) clear the device, or a
>skosh less to grab it.
>
>OPTIONAL: Take a dose of your favorite relaxation agent <grin>.
>
>Take your time. Practice on junk boards: heat, tweeze, pluck.
>
>Now you can remove any smt you can get this contraption on to.
>
>Ymmv. No pics available. I'm omitting the green stuff and presenting
>only basics. Real tools cost BIG bucks.
>

I strongly agree about the lighting [1] and magnification - and for
serious SMD work, stay off the espresso!

But it really isn't necessary to use a double soldering pen to remove a
bitty 0603 chip. It goes like this:

Use a normal solder pen with a small pointed tip.

1. Melt solder at left-hand end of chip.

2. Switch to right-hand end, melt solder there.

3. Back to left.

4. Ri... Oh, it already came off. Wasn't that easy?

[1] For lighting, get one of these - it's brilliant!

USA: http://www.ikea.com/us/en/catalog/products/50128713

UK: http://www.ikea.com/gb/en/catalog/products/50128708

More info here:
http://www.ifwtech.co.uk/g3sek/in-prac/best-of.htm#0809

--

73 from Ian GM3SEK 'In Practice' columnist for RadCom (RSGB)
http://www.ifwtech.co.uk/g3sek
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Brett Howard

Re: K3 mods and methods: smt resistor/capacitor de-soldering

In reply to this post by David Windisch

We've got a tech who is amazing with a soldering iron. He has two very
nice soldering irons on the bench next to him at all times. All this
guy does is work magic with a soldering iron all day long...

His two irons are one with a bit of a cup in the end of the tip (for
holding solder) and the other is a smaller pencil type. If he simply
wants to remove a small 2 in SMT component he just sets the largest tip
over the top of the part and then slides it off the pads.

The only time he uses both irons is if he needs to reuse that SMT
component. If he's doing that he then just uses the two irons and
simply picks the component up with the irons (one in each hand) that way
the tweezers aren't needed...

Just a few other thoughts...

~BTH

On Mon, 2010-02-01 at 07:13 -0800, David Windisch wrote:

> It's a process, it's easier than you think, and there is plenty of room for
> creativity. I don't pretend to know it all; this works for me.
>
> BASICS:
>
> Light up the work area.
>
> Get comfortable seating.
>
> Buy a pull-down magnifier. Don't skimp here. I use OPTI-VISOR, 3X lenses.
> Buy 2 of the physically-smallest low-power soldering pencils.
> Buy a *large* decorative clothes pin.
> Buy various-length, variously-shaped stainless tweezers.
>
> Attach the pencils to the clothes pin. Hose-clamps?
> Shim the jaws open so the pencil-tips get proper spacing to (just) clear the
> device, or a skosh less to grab it.
>
> OPTIONAL: Take a dose of your favorite relaxation agent <grin>.
>
> Take your time. Practice on junk boards: heat, tweeze, pluck.
>
> Now you can remove any smt you can get this contraption on to.
>
> Ymmv. No pics available. I'm omitting the green stuff and presenting only
> basics. Real tools cost BIG bucks.
>
> Brgds, Dave, W8FGX

DaveL G3TJP

Re: K3 mods and methods: smt resistor/capacitor de-soldering

In reply to this post by David Windisch

Simple two pole devices don't need much "engineering" to remove, but I would caution against the "cut in half with sharp cutters" method as it can lead to damaged pads.

I can't be bothered creating special tools for two pole devices, just a quick flip with a pair of soldering irons, then use a bit of desolder braid to clean up the pads.

What can be quite exciting is the removal of multi-pin devices and for that, Chipquik is a wonderful friend. It's not cheap, but then it's worth using an inch to remove a high pin density chip. The flux they supply is great for cleaning off pads with cotton buds. Chipquik is a great substitute for a hot air desoldering station, see here, (and get your free sample!).

http://www.chipquik.com/

73 DaveL G3TJP
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W6ODJ

Re: K3 mods and methods: smt resistor/capacitor de-soldering

Dave,

Their video showing surface-mount soldering techniques is double-recorded in the audio channel. Pretty frustrating. Do you know someone there you can tell?

--Oliver
W6ODJ

On 2 Feb 2010, at 3:42 AM, David Lankshear wrote:

> Simple two pole devices don't need much "engineering" to remove, but I would caution against the "cut in half with sharp cutters" method as it can lead to damaged pads.
>
> I can't be bothered creating special tools for two pole devices, just a quick flip with a pair of soldering irons, then use a bit of desolder braid to clean up the pads.
>
> What can be quite exciting is the removal of multi-pin devices and for that, Chipquik is a wonderful friend. It's not cheap, but then it's worth using an inch to remove a high pin density chip. The flux they supply is great for cleaning off pads with cotton buds. Chipquik is a great substitute for a hot air desoldering station, see here, (and get your free sample!).
>
> http://www.chipquik.com/
>
> 73 DaveL G3TJP
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>

W6ODJ

Re: K3 mods and methods: smt resistor/capacitor de-soldering

Dick,

You're right. Operator error. Sri. Very well done videos.

Oliver
W6ODJ

On 2 Feb 2010, at 10:30 AM, Dick Dievendorff wrote:

> I didn't hear double audio. Could you have started the player multiple
> times?
>
> Excellent videos!
>
> Dick
>
>
> -----Original Message-----
> From: [hidden email]
> [mailto:[hidden email]] On Behalf Of O. Johns
> Sent: Tuesday, February 02, 2010 10:01 AM
> To: David Lankshear
> Cc: [hidden email]
> Subject: Re: [Elecraft] K3 mods and methods: smt resistor/capacitor
> de-soldering
>
> Dave,
>
> Their video showing surface-mount soldering techniques is double-recorded in
> the audio channel. Pretty frustrating. Do you know someone there you can
> tell?
>
> --Oliver
> W6ODJ
>
>
> On 2 Feb 2010, at 3:42 AM, David Lankshear wrote:
>
>> Simple two pole devices don't need much "engineering" to remove, but I
> would caution against the "cut in half with sharp cutters" method as it can
> lead to damaged pads.
>>
>> I can't be bothered creating special tools for two pole devices, just a
> quick flip with a pair of soldering irons, then use a bit of desolder braid
> to clean up the pads.
>>
>> What can be quite exciting is the removal of multi-pin devices and for
> that, Chipquik is a wonderful friend. It's not cheap, but then it's worth
> using an inch to remove a high pin density chip. The flux they supply is
> great for cleaning off pads with cotton buds. Chipquik is a great
> substitute for a hot air desoldering station, see here, (and get your free
> sample!).
>>
>> http://www.chipquik.com/
>>
>> 73 DaveL G3TJP
>> ______________________________________________________________
>> Elecraft mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:[hidden email]
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>