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From: rstevew@armory.com (Richard Steven Walz)
Subject: Re: Desoldering: where's a cheap, small torch
Organization: The Armory
Date: Tue, 16 Aug 1994 10:43:40 GMT
Message-ID: <CuMJ4u.968@armory.com>
References: <32dm6q$eki@lastactionhero.rs.itd.umich.edu> <D> <1994Aug12.133745.28725@kocrsv01.delcoelect.com>
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In article <1994Aug12.133745.28725@kocrsv01.delcoelect.com>,
Jim Buchanan <c22jrb@kocrsv01.delcoelect.com> wrote:
>
>In article <32dm6q$eki@lastactionhero.rs.itd.umich.edu>, ocg@cw-u02.umd.umich.edu (John Roldan) writes:
>[...]
>> something in RadioShack a while back.  I'd hate to convince my wife I 
>> need to buy a big torch and one of those metal masks I see the riveters 
>> wwearing.
>[...]
>
>I've used the Radio Shack mini-torch. The main problem with it is the poor
>seal of the valve (a pin on a threaded screw that is also used to puncture
>the seal on the butane cartridge). If you don't use all the gas in a week
>or two, it all leaks out.
---------------------------
Yep, those are crap! Some of them have good valves, but you almost have to
test them in the store! Buy a real full sized utility propane torch! That's
NOT a welding torch and you don't need a mask!!
-Steve

>I usually use the same torch I use for household plumbing. It's cheap,
>useful for many other jobs, and a tank of propane lasts for a long time.
----------------------------
I have used the same four tanks I bought in a power outage that lasted
three days in 1982, and they were $2.50 and $3 aa piece, and I have only
gone through one and a half of them!!!
-Steve

>I heat the IC solder till it looks like it's flowing, then wait a little
>longer before I apply force to the device. This ensures that the solder is
>really soft, and minimizes physical damage.
-----------------------------
I apply the force and wait for it to let loose! Never lost a one!
-Steve

>Even though I use this method, it's not ideal. Solder and parts can fly
>around if you're not careful, and fire is a real possibility. I have set
>the board itself on fire this way.
------------------------------
Fiberglass boards are inflammable! They are epoxy! Do it outdoors and blow
them out with your mouth! They only do that after the first 20 chips off
them!
-Steve

>Jim Buchanan                    
>c22jrb@kopt0017.delcoelect.com  "Catch 22"
>c22jrb@delphi.com               
>'73 BMW R75/5                   "Frau Bluecher"
-------------------------------------------------
Nevertheless, the propane torch is SO useful, (the larger one), and SO
versatile that I cannot imagine a roboticist of ANY scale getting by
without one! And all chip removal with them should be done outdoors or in a
VERY well-ventilated room, with safety glasses, ( welding mask is NOT
necessary at all! ), respirator or elastic breathing mask; it should be
done so the fumes escape DOWNWIND, and the torch needs to be adjusted to
its lowest setting. Buy the better one with the brass valve handle and not
the cheap plastic one with the hinky valve! Use a bowl of water to drop hot
chips into to preserve them against die heating, and mount the board in a
vice edge-on to your eyes so you may see both sides at once and place your
chip puller (can be the cheap steel one) first, and pull while applying
heat. I recommend going right down the row, as one will tend to begin
heating the next, and thus it is speeded up. It also doubles as a heat gun
for shrink tube, a giant soldering iron for soldering wires to bolts or
other large heatsinks, and I use another tank and tube and my large mouthed
bunsen burner in front of the TV to toast marshmallows for guests! I
sacrificed a found torch unit years ago to having a detached tank, and it
has been very useful. I have done a bunch of glasswork with it as well.
I have also done silver soldering of jewelry and other art. It even can
weld very small pieces of the right kinds of steel. And it can be used to
completely roast and eliminate a marching column of over ten thousand ants
by just waving it over them burning out their eyes, antennae, and brains,
so they don't even know HOW to come back!!! Two such attacks will usually
cripple a home ant colony for up to two years!;) Wave it over them just
slow enough to roast them and it doesn't leave even the slightest mark on
the floor, even full blast!!! Just don't stop moving!!;->
-Steve Walz   rstevew@armory.com

