Best way to desolder?

[meirman]

What is the best way to desolder?

I have tried solder wicks, single bulb solder suckers, pen-like solder
suckers, solder suckers with integrated soldering irons, and I've
tried heating the item and shaking off the solder.

My current best method is heating the solder and blowing it off with a
plastic soda straw. This sometimes leaves solder all over the place,
and I have to use my fingernail or a chopstick to nudge the solder off
places where it is shorting two connectors, or where it might fall and
short something (which is everywhere).

I ask now because I have, that I found in the trash years ago, about
12 Western Electric circuit boards, obsolete now, each with up to 7
6-pole double throw relays. Needless to say, Western Electric used
high quality relays, but when I try to desolder them from the boards,
I lose a lot of the connections (there are 20 of them), and often I
lose one of the two connections that goes to the relay coil, and I've
ruined the relay.

I need a better way to get these relays disconnected from the circuit
boards.

Help?

Meirman

 

[Travis Jordan]

What is the best way to desolder?

For removing PC mounted relays I'd use a SOLDAPULLT (tm) followed, if
necessary, by a little solder wick.

 

[James Sweet]

What is the best way to desolder?

I have tried solder wicks, single bulb solder suckers, pen-like solder
suckers, solder suckers with integrated soldering irons, and I've
tried heating the item and shaking off the solder.

Depends what you're trying to solder, aside from very expensive vacuum
stations I've had the best luck with the Radio Shack desoldering iron (one
of the few truly useful things they sell) for larger joints, and solder wick
dipped in liquid flux for smaller stuff. The flux is really the key, it
dries out quickly from solder wick which then works poorly.

 

[Cubzilla]

">

My current best method is heating the solder and blowing it off with a
plastic soda straw.

Try sucking,

 

[Ken]

For removing PC mounted relays I'd use a SOLDAPULLT (tm) followed, if
necessary, by a little solder wick.

The only thing I would add to your suggestion is a web site:
http://www.hvwtech.com/pages/products_view.asp?ProductID=444
and the comment that desoldering takes some skill. My suggestion would
be that he practice on some items that he doesn't need before attempting
to desolder the real items he wants.

 

[worldcitizen]

What is the best way to desolder?

I have tried solder wicks, single bulb solder suckers, pen-like solder
suckers, solder suckers with integrated soldering irons, and I've
tried heating the item and shaking off the solder.

My current best method is heating the solder and blowing it off with a
plastic soda straw. This sometimes leaves solder all over the place,
and I have to use my fingernail or a chopstick to nudge the solder off
places where it is shorting two connectors, or where it might fall and
short something (which is everywhere).

I ask now because I have, that I found in the trash years ago, about
12 Western Electric circuit boards, obsolete now, each with up to 7
6-pole double throw relays. Needless to say, Western Electric used
high quality relays, but when I try to desolder them from the boards,
I lose a lot of the connections (there are 20 of them), and often I
lose one of the two connections that goes to the relay coil, and I've
ruined the relay.

Something I've done in the past that works pretty good is to heat the
solder joint with your iron, remove the iron and then imediatly brush
the hot solder away with an old tooth brush. Works good and all that
is left to do is remove all the solder you have brushed away. Try to
brush in a direction so that the debris is easily removed. I've even
been know to lay a peice of cloth next to the solder joint before
brushing and let that catch the trash solder. Taping down a peice of
paper works too. Use a hot iron and get in and out fast so that you
don't damage the part. A not so hot iron will force you to stay longer
on the joint before the solder melts and could damage the part. Good
luck.

 

[b]

What is the best way to desolder?

(snip)

I use pieces of old 75 ohm coax cable, with the core removed so just
the braid remains, dipped in flux. Works like a dream. usually need to
use a hot iron (40w at least). Practise on some old junk first to get
the hang of it.
-Ben

 

[Travis Jordan]

I use pieces of old 75 ohm coax cable, with the core removed so just
the braid remains, dipped in flux. Works like a dream. usually need to

This would be solder wick.

 

[Isaac Wingfield]

What is the best way to desolder?

I have tried solder wicks, single bulb solder suckers, pen-like solder
suckers, solder suckers with integrated soldering irons, and I've
tried heating the item and shaking off the solder.

My current best method is heating the solder and blowing it off with a
plastic soda straw. This sometimes leaves solder all over the place,
and I have to use my fingernail or a chopstick to nudge the solder off
places where it is shorting two connectors, or where it might fall and
short something (which is everywhere).

I ask now because I have, that I found in the trash years ago, about
12 Western Electric circuit boards, obsolete now, each with up to 7
6-pole double throw relays. Needless to say, Western Electric used
high quality relays, but when I try to desolder them from the boards,
I lose a lot of the connections (there are 20 of them), and often I
lose one of the two connections that goes to the relay coil, and I've
ruined the relay.

I need a better way to get these relays disconnected from the circuit
boards.

Help?

Back in the days when computer memory chips looked like sixteen-legged
caterpillars and cost a fortune each, a friend of mine got his hands on
a pile of circuit boards with dozens of the things soldered in.

His solution was to grab a board by the corner with pliers and hold it
in the flame of his kitchen stove until the solder turned all shiny. A
quick flip to bang the edge of the board, upside down, on the edge of
the stove, deposited all the chips -- and lots of solder splats -- on
the vinyl flooring.

Almost all the chips were good. He was happy; his wife was distinctly
*not*.

Isaac

 

[meirman]

In sci.electronics.repair on Mon, 07 Mar 2005 20:36:45 -0800 Isaac

These are great boards btw. Very thick and they have half-inch high
steel frames on three sides of them.

Back in the days when computer memory chips looked like sixteen-legged
caterpillars and cost a fortune each, a friend of mine got his hands on
a pile of circuit boards with dozens of the things soldered in.

His solution was to grab a board by the corner with pliers and hold it
in the flame of his kitchen stove until the solder turned all shiny. A
quick flip to bang the edge of the board, upside down, on the edge of

This sounds great. One more reason I wish I had a gas stove.

Thanks a lot, and thanks to all of you for a lot of good ideas.

Also someone emailed me to suggest a heat gun applied to the solder
side, pointing up, and gravity or pliers or a pry to the other side.

the stove, deposited all the chips -- and lots of solder splats -- on
the vinyl flooring.

Almost all the chips were good. He was happy; his wife was distinctly
*not*.

Isaac

Meirman

 

[meirman]

In sci.electronics.repair on Sun, 06 Mar 2005 21:51:47 GMT Ken

The only thing I would add to your suggestion is a web site:
http://www.hvwtech.com/pages/products_view.asp?ProductID=444

Thanks to both of you.

I looked at the webpage and then I looked at my solder suckers (I have
two, bought at rummage sales I think.)

Much to my surprise, one of them was a Soldapullt, although a
different model from the one shown. Mine is 3 inches shorter, but the
stroke is only 3/4 inch shorter. 2 1/2 inches instead of 3 1/4.

But mine doesn't work at all, and from the web page I realized I must
replace the o-ring.

The other one is one of those imitations they mention, and I don't
think it works very well based on how well it sucks on my finger --
that's probably why they sold it.

and the comment that desoldering takes some skill. My suggestion would
be that he practice on some items that he doesn't need before attempting
to desolder the real items he wants.

Is there a problem letting the soldeapullt touch the soldering iron
tip -- Does that damage it? Should I make sure that I only touch the
liquid solder?

I don't think I'll be able to get a replacement tip for the one I
have, although if it wears out, I'd be willing to buy a new model.

Thanks again.

Meirman

 

[meirman]

In sci.electronics.repair on Sun, 06 Mar 2005 18:41:12 GMT "James

Depends what you're trying to solder, aside from very expensive vacuum
stations I've had the best luck with the Radio Shack desoldering iron (one
of the few truly useful things they sell) for larger joints, and solder wick
dipped in liquid flux for smaller stuff. The flux is really the key, it
dries out quickly from solder wick which then works poorly.

I actually have liquid flux. I bought a small bottle of it new but
hadn't realized yet that I have a use for it. I'll try that as you
suggest.

Meirman

 

[meirman]

In sci.electronics.repair on Sun, 6 Mar 2005 21:42:16 -0000 "Cubzilla"

">

Try sucking,

I've worried about that, but I think I've got it down to only
blowing. .... You're not serious, are you?




Meirman

 

[meirman]

In sci.electronics.repair on 7 Mar 2005 07:33:17 -0800 "worldcitizen"

Something I've done in the past that works pretty good is to heat the
solder joint with your iron, remove the iron and then imediatly brush
the hot solder away with an old tooth brush. Works good and all that
is left to do is remove all the solder you have brushed away. Try to
brush in a direction so that the debris is easily removed. I've even
been know to lay a peice of cloth next to the solder joint before
brushing and let that catch the trash solder. Taping down a peice of
paper works too. Use a hot iron and get in and out fast so that you
don't damage the part. A not so hot iron will force you to stay longer
on the joint before the solder melts and could damage the part. Good
luck.

I'll try those things too. I actually have a lot of experience doing
this, and it's worked pretty well, although slowly, and I knew there
must be a better way.

That's why I was surprised when I did so much damage to so many of the
relays and ruined about 3 of them, out of 7 that I removed.

Thanks to you and to all.


Meirman

 

[Ken]

In sci.electronics.repair on Sun, 06 Mar 2005 21:51:47 GMT Ken



Thanks to both of you.

I looked at the webpage and then I looked at my solder suckers (I have
two, bought at rummage sales I think.)

Much to my surprise, one of them was a Soldapullt, although a
different model from the one shown. Mine is 3 inches shorter, but the
stroke is only 3/4 inch shorter. 2 1/2 inches instead of 3 1/4.

But mine doesn't work at all, and from the web page I realized I must
replace the o-ring.

The other one is one of those imitations they mention, and I don't
think it works very well based on how well it sucks on my finger --
that's probably why they sold it.




Is there a problem letting the soldeapullt touch the soldering iron
tip -- Does that damage it? Should I make sure that I only touch the
liquid solder?

I don't think I'll be able to get a replacement tip for the one I
have, although if it wears out, I'd be willing to buy a new model.

Thanks again.

Meirman

If you will go to the following:
http://www.hvwtech.com/pages/products1a.asp?CatID=36&SubCatID=154
you will see you can purchase a refurb kit which includes a replacement
tip. (Even a local Radio Shack might have them) It is true that
eventually the tip will become damaged, but it does not occur as quickly
as one would expect. Place the tip as close to the component as you can
and release the solder sucker vacuum when you see the solder flow around
the component. Again, practice is the best method to learn how to
effectively do this. When I hired a technician for my crew many years
ago, I would have them practice on scrap PWBs for a week before working
on real product. One can do a lot of damage quickly to an expensive
circuit board if you don't have the process perfected. Certainly you
won't need to practice that long, but some is advised in my opinion.

 

[jtaylor]

This sounds great. One more reason I wish I had a gas stove.

Propane torch. Heat & beat (the board against an edge).

 

[Stein-Olav Lund]

For removing PC mounted relays I'd use a SOLDAPULLT (tm) followed, if
necessary, by a little solder wick.

To remove leaded components from plated-thru holes
nothing beats a desoldering iron with vacuum pump built into the handle.
We use one made by Den-on Instruments in Japan called SC7000.
It is somewhat expensive (around US$ 500)
Units with the pump on the table and a hose in between lose much of
their efficiency in my experience.

Stein

 

[Isaac Wingfield]

Also someone emailed me to suggest a heat gun applied to the solder
side, pointing up, and gravity or pliers or a pry to the other side.

Takes too long to heat up to solder-melting temperature. Long before
that, the components will be cooked.

Isaac

 

[Mika Lindblad]

Takes too long to heat up to solder-melting temperature. Long before
that, the components will be cooked.

Isaac

 

[Mika Lindblad]

Also someone emailed me to suggest a heat gun applied to the solder
They'll be fine. With correct (high enough) heat, and proper working, most
of the components will be in excellent condition.
I've even seen surface mount IC's being installed with a regular heat gun..

One must not fry the components. Just heat the solder (from the solder side
only..), hit the board lightly, and the components will drop off the board.
Well, unless their legs have been turned. In that case, it'll be a bit
trickyer.
And of course, one spot of the board must not be heated too long. That too
will cook it up.