"clifto" wrote in message
...
bill wrote:
... making your own soldering iron by
using the carbon rod from a C cell battery
(carbon zinc cell)
http://www.coldheat.com/
They have a three-minute QVC commercial for it.

Good info Clif...Bill, whatever,
Boy, you new guys sure don't know what's been around for a long
time...(:-)
OLD idea. LOW voltage, HIGH current.

It is called "resistance soldering". I believe it is most important to
know that the current is only passed through ONE of the pieces being
soldered, not through the joint being soldered. In the QVC video, notice
that he only does one piece of wire and what look like solder blobs on a
board....

In fact, this is how soldering *GUNS* work! The gun "TIP" is a 'wire' &
has a high current from a transformer secondary that is in the gun body.
Long ago I stopped buying soldering gun tips and just use #12 or #14 solid
copper wire. Sometimes in really weird shapes to unsolder IC and the like.
It is interesting to see what the strong magnetic field around the tip does
to molten solder... Reminds me of that recent NASA video about the solder
flux in space...
The (soldering gun) secondary is 1 or 2 turns for fractions of a volt at
MANY amps. I should measure it, but I think it CAN NOT damage a transistor
since it is less than 0.4 volts (I think, far less)
I have a professional resistance soldering unit used for making dental
braces and similar things and it is powerful enough to do PL259s _VERY_
well. Heavy wire to the probe and large clamp and several secondary taps.
Interesting thing is that the manufacturer uses the blue handles from
Weller, so it looks like a Weller soldering iron, but with an extreemly worn
and oxidized tip, since it is not tinned. Looks carbon-like.

More info I found with a quick Google:

Didn't read it all, but an explanation:
http://www.geocities.com/budb3/arts/meth/sldrrst.html

Build your own:
http://www.trainweb.org/bristol-s-ga...jects/rsu.html


The web had anything!


http://www.wassco.com/regressolhan.html

http://www.contacteast.com/product/g...p?parent_id=16
http://www.greenspun.com/bboard/q-an...?msg_id=004VTC
Build your own (model railroad magazine references)

http://index.mrmag.com/tm.exe?opt=S&...put=3 &sort=d

http://www.ares-server.com/Ares/Ares...partment&ID=81
Beware URL WRAP






It's obvious that it's
running current through the object to be soldered; they show the little
red "power" light going on and off as they touch and un-touch a solder
pad on a circuit board.

Like the Radio Shack butane unit, the device is $20 and tips are $10.
They have three different tips shown. Takes 4 AA batteries.

"This tool is appropriate for most electrical projects with wires between
18-24 gauge, small jewelry repair, and electronic projects."

"We do not recommend it for soldering of large metallic components that
require a lot of heat transfer, such as heavy gauge wire. Also be aware
that high temperatures will be created during active soldering; please
consult your component's datasheet for any special precautions needed."

"What is the spark I see sometimes during soldering?
"The spark (arc) is caused [sic] electrical current passes from one half
of the tip to the other. Although the tool's spark should not damage
any electrical or electronic components, we recommend caution when
soldering sensitive components. Also, ensure that the tool is not used
in flammable or explosive environments, such such as near gas or
gasoline fumes."

One thought that occurs to me is that it looks like a DYNAMITE tool for
desoldering with a suction device, since it appears that solder doesn't
stick to the tip it ships with. Can't speak for the other tips; they
look more metallic and are not demonstrated on the site. They recommend
wick for desoldering, but those of us not of that religion might have
an alternative.

--
"Kerry arrived in-country with a strong anti-Vietnam War bias and a
self-serving
determination to build a foundation for his political future."
-- Rear Admiral Roy Hoffmann, USN (Ret.), May 4, 2004