Subject: Re: Building a resistance solder machine

From: [email-masked] (Fredric W. Dabney)
Date: 11 Dec 1994 07:08:17 GMT

Ian Simpson ([email-masked]) wrote:
etc-rification

: I mounted the rod in an old soldering iron handle (heat resistant 
: plastic) using telescoping brass tubing to match the diameters
: of various components. 

: The connection to the rod from the battery charger is about #8 flex cable,
: again connected to the nested brass tubing. (I crimped it all with an 
: industrial strength crimping tool).

: I modified the battery charger by putting a normally on push button 
: switch in the primary circuit (mains side of the transformer) to allow
: me to postion the rod, brass components etc. before applying
: the current. If you don't do this you will ruin small components with 
: burns from the arcing. 

: Does it work? yes, but my 6 amp battery charger is not strong  
: enough for my needs, also keeping my foot on the push switch 
: and releasing to turn on the current is not natural and akward.

: Modifications for the future:
: A larger battery charger of transformer/rectifier.(a friend uses a 15 amp 
: lashup with no problem)

: A better and independant control for foot operation. Probably a dimmer
: switch mounted in a box with a plug, this should also work for my
: dremel motor tool and setting the temperature of my soldering irons. 

Watch out!!!!  A triac-type dimmer may either blow itself into the next
county with such an inductive load, and Dremel does NOT endorse the idea. 
Most of their tools now use a permag motor with a bridge rectifier inside
the case.  Use of half-wave rectified scr controls can destroy the tool,
but a full wave control works fine.  I use a variac with a resistive foot
control for my small power tools- Dremel, Unimat, Sherline, etc.  I also
picked up a small adjustable xformer which was made by Ungar for my
soldering pencil- type iron.

Sears has a foot switch in their tool catalog which is heavy enough for
larger tools like a drill press, table saw, etc.  In my shop, every thing
is controlled by a foot control.  It makes life a lot easier.

See if you can find a catalog by a company that supplies tools for
jewelers- Vigor used to be such a company.  After you quit salivating all
over the pages, you might find a resistance unit or just the tool for use
with your own transformer for a more rational price than PBL wants.  Or
not- I haven't priced one in decades.  I bought mine from a company called
"Brookstone" which used to offer a great line of precision tools, but they
went yuppie with exotic garden and kitchen tools and I haven't heard from
them in many years.  Pity.

Again, I'd suggest a Variac feeding a husky fixed xformer via a foot
switch for the current source.  These beasts can be found in surplus
places sometimes for a good price.  Five amp minimum, I'd say for the
input into a step-down xformer.  Mine is not metered- I adjust for smoke
as the expression goes so can't give you any idea of what I'm using.

I'll look into it and try to post some numbers later.

Fred D.

---

From: [email-masked] (Lawrence Boul)
Date: Fri, 16 Dec 1994 08:39:29

In article <[email-masked]> [email-masked] (Vance Bass) writes:
>From: [email-masked] (Vance Bass)
>Subject: Re: Building a resistance solder machine
>Date: 14 Dec 1994 12:48:26 -0500

>Can someone who actually uses one give some details regarding resistance vs.
>torch (and what kind of torch you use)?
>-- 

As Fred D points out all these tools have their place.  I have a Proxxon 
(German) micro torch than runs on butane (lighter fuel).  It has push button 
ignition and cost around NZ$90 =US$45.  Its one of the best buys I ever made 
and was prompted by the success I had with a cheap (US$10) Asian made torch I 
picked up at a hardware store.  At that price you can afford to experiment.

I have not tried resistance soldering yet -which is why I'm following this 
thread- but here are some thoughts on flame soldering.

Temperature is very high and thus the soldering process is fast.  Unsoldering 
adjacent parts is prevented by placing wet paper tissues around them.  I like 
to liquid acid flux and then place a small piece of resin cored solder near 
the joint.  A lick of flame, and the solder wicks into the joint beautifully, 
partly because of the fast heating and partly because the resin core is doing 
its job (which does not happen when you carry solder to the work on the iron 
because it burns off before you get there).  Flame is very good for big lumps 
of brass that require a lot of heating.  Setting pieces up to hold them  
obviously requires some thought and wooden clothes pegs etc. don't work too 
well!

I'd be interested in any soldering tips anyone has to offer. 

:-{  Lawrence

---

From: Flint Smith <[email-masked]>
Date: 14 Dec 1994 04:38:52 GMT

It seems there are many ways to make a resistance solder machine.  I
myself have used the core from a battery as a soldering iron in an emergency
in the desert. But...

What is it good for in a metalworking/hobby/modeling setup.  What
makes it preferable to other techniques?

1) you can make it for $20
2) localized heat delivery
3) ?

Flint Smith

[email-masked]

---

From: [email-masked] (Gregory Clark)
Date: 16 Dec 1994 01:55:52 GMT

In article <[email-masked]>, [email-masked] (Vance Bass) says:
>
>In article <[email-masked]> Flint Smith <[email-masked]> writes:

>That's the key for me -- being able to attach a part, then solder on something
>else nearby withou having the whole thing collapse on me.
>
>  I'm about to start on the tender, which
>is much more complex, and I can't imagine how I'm going to hold it all 
>together while I'm soldering.  
>

When I built my tender I simply riveted the thing to gether and only used
the solder as an extra seal on the seams. I used an old 1.5 pound iron
 and a gas blow torch to heat it and followed the 
procedures used by copper basin makers of 75 years ago.
 Everything being riveted tends to hold it together quite well ;->
What kind of engine/tender are you building? And I guess what scale.
Mine being 1" scale made this easy. Riveting HOn3 might be tougher.

[email-masked]
[email-masked]

---

From: [email-masked] (Fredric W. Dabney)
Date: 14 Dec 1994 18:25:03 GMT

Flint Smith ([email-masked]) wrote:
: It seems there are many ways to make a resistance solder machine.  I
: myself have used the core from a battery as a soldering iron in an emergency
: in the desert. But...

: What is it good for in a metalworking/hobby/modeling setup.  What
: makes it preferable to other techniques?

: 1) you can make it for $20
: 2) localized heat delivery
: 3) ?

Handy.  I've a resistance machine- a big commercial one I got years ago. 
For me, it is the thing I use when brute force is called for, since I
don't like running a torch with all paint and solvents around the bench,
and it often isn't handy to go outside to work.

Depending on the toolpiece, one can set everything up, holding parts in
place with the tweezers or the handpiece and blip the footswitch and have
a soldered part.  Choice 2 is the operative one to supplement this.

At the other end of the spectrum, a Wahl or similar cordless iron is very
handy if one is soldering small piping and other light but intricate parts
on a steam engine, etc.  Here it is the lack of the power cord hanging in
the way while one is trying to juggle sixteen other things which makes it
so useful.

I've been intending to get a set of tweezers for my resistance machine,
but for now my soldering tools of choice are the machine (which can be
stepped down so far it won't even get .010 wire warm), a small 47 watt
Ungar pencil iron with an adjustable transformer control (also Ungar- both
very old) and my Wahl quick charge cordless.  They all have their place,
I'd miss any of them, but I could live without any one of them.

But the matter of tools is a very personal one.  If I have a lot of
repetitive wire bending to do, I'll make a jig first, even though it may
take as long as just bending the wire.  But the jig means that the results
will match.  And if the job is nit-picky, I'll go to the local rock hound
shop and buy a pair of pliers, and grind the tips just for the job at hand.

Fred D.

---

From: [email-masked] (Vance Bass)
Date: 14 Dec 1994 12:48:26 -0500

In article <[email-masked]> Flint Smith <[email-masked]> writes:
> ...

I've been building the cab, boiler jacket, domes, etc on a small live-steam
locomotive.  The cab was tricky in that I had to wire and clamp the whole thing 
together in order to start soldering.  I'm about to start on the tender, which
is much more complex, and I can't imagine how I'm going to hold it all 
together while I'm soldering.  I figure that a resistance solderer will let
me tack on everything with only local heat gain.  (I've seen a videotape by
the owner of PBL on soldering, which amounts to a plug for resistance units,
which he sells :-)  That showed me how useful they are for very fine work.)

Can someone who actually uses one give some details regarding resistance vs.
torch (and what kind of torch you use)?
-- 
=-=-=All the above are OFFICIAL POSITIONS and are ABSOLUTELY TRUE!=-=-=
Vance Bass                    	  	  Reply-to: [email-masked]
"It don't mean a thing if it ain't got that certain je ne sais quoi."
						   -- Peter Schickele

---

From: [email-masked] (Ian Simpson)
Date: 22 Dec 1994 15:45:09 GMT

In article <[email-masked]>, "Vance R. Bass, Nashville 
Garden Railway Society" <[email-masked]> says:
>
>Can someone help me with further info on carbon electrodes for this
>rig?  (Battery brands/sizes, date you actually found one in there, etc.)
>
Try an electric motor overhaul shop. Brushes from larger motors/generators
are ideal. Even a vehicle parts shop may have what you need (alternator
brushes). These are very convenient as they often have a copper braid
moulded in which will ensure adequate current flow to the carbon.

Ian

---

From: [email-masked] (Bob Grime)
Date: Fri, 23 Dec 1994 02:19:47 GMT

In article <[email-masked]>,
Vance R. Bass, Nashville Garden Railway Society <[email-masked]> wrote:
>Friends,
>
>I have followed all the excellent advice given by the kind readers here
>and in rec.crafts.metalworking, and now have a homebuilt resistance
>solderer sitting on my workbench.  Total cost is still well under US$50.
>
>The catch is that I can't use it yet because I don't have a source of
>carbon rod yet.  (I know that I can buy them from MicroMark, but I had
>my heart set on scrounging EVERYthing...).
>
>I have dismembered two different sized (AA and C) alkaline batteries,
>and all I found in the center of either was a dubious-looking silvery
>goop.  There WAS some cakey carbon-looking stuff around the outermost
>layer, but it was certainly not useable.
>
>I tried my local home improvement warehouse, and all they had in their
>welding department was metal rods of various sorts.  The young lady
>who helped me was very knowledgeable about these products, but knew
>absolutely nothing about anything not on their shelves.
>
>Heartfelt thanks to all who have responded and followed up on this
>question!  What a GREAT group this is!
>
>Vance

Vance,

I have been following this topic with interest as I built myself one of 
these most useful tools from a Scope soldering iron innards and transformer.
With a little practise you can solder numbers, makers plates and even 
single rivets on. 

Just a couple of tips from bitter experience if I may. When soldering 
individual numbers or small makers plates, place a small piece of thin 
aluminium sheet (not foil, it is too thin) between the carbon rod and the 
face of the makers plate. 
This will prevent the concentration of heat at the tip of the carbon from 
burning the fine detail of the plate. Secondly, don't lift the carbon rod 
off the job while the power is still on. You will draw a small arc and 
the tool will become a spark eroder and will burn a hole or burn off any 
fine detail in (literally) a flash. 

The procedure I use is to tin the back of the part to be soldered on 
with a very small amount of solder, add a small amount of liquid flux to 
the back of the part and place it in place on the loco side or where ever. 
Place the carbon rod on the part and when it is correctly lined up in the 
exact spot apply pressure and turn on the power. Watch to see the solder 
appear at the edge of the part. Once this happens switch off the power and 
maintain the pressure until the solder has solidified, then release the 
pressure. The pressure must be vertical or once the solder melts you may 
skid side ways and ruin the job.

They are a great tool and you will be able to do very fine soldering work 
just not possible with an ordinary iron.

Regards, Bob Grime.     [email-masked]

---

From: [email-masked] (Ted Becker)
Date: Thu, 22 Dec 1994 08:19:59 GMT

Carbon rods are available in welding supply shops.  They are made for 
carbon arc torches and are available in various diameters.

Vance R. Bass, Nashville Garden Railway Society ([email-masked]) wrote:
: Friends,

: I have followed all the excellent advice given by the kind readers here
: and in rec.crafts.metalworking, and now have a homebuilt resistance
: solderer sitting on my workbench.  Total cost is still well under US$50.

: The catch is that I can't use it yet because I don't have a source of
: carbon rod yet.  (I know that I can buy them from MicroMark, but I had
: my heart set on scrounging EVERYthing...).

: I have dismembered two different sized (AA and C) alkaline batteries,
: and all I found in the center of either was a dubious-looking silvery
: goop.  There WAS some cakey carbon-looking stuff around the outermost
: layer, but it was certainly not useable.

: I tried my local home improvement warehouse, and all they had in their
: welding department was metal rods of various sorts.  The young lady
: who helped me was very knowledgeable about these products, but knew
: absolutely nothing about anything not on their shelves.

: Can someone help me with further info on carbon electrodes for this
: rig?  (Battery brands/sizes, date you actually found one in there, etc.)

: Heartfelt thanks to all who have responded and followed up on this
: question!  What a GREAT group this is!

: Vance

---

From: [email-masked] (Fredric W. Dabney)
Date: 22 Dec 1994 08:33:05 GMT

It may be that you need to find an old-fashioned carbon-zinc type battery
which used to be the only sort made, but which is now outmoded because
their shelf and service life are so short compared to modern "alkaline"
cells.  I know that old battery had a nice carbon center rod, because I
used to take them apart as a kid.  I never /did/ anything with them but
being a kid, I still had to do it...

Fred D.

---

From: adrianw@cassius (Adrian Whichello)
Date: Thu, 22 Dec 1994 21:57:09 GMT

>layer, but it was certainly not useable.
[snip]
>question!  What a GREAT group this is!

Vance, the LAST thing you want is an alkaline battery. Get a an ordinary
NON-alkaline carbon-zinc cell: an Eveready silver/red/black type if they are
the same in USA as they are here in Australia. Or a cheap "Flying Bomb" brand
>from  China, even! But not an alkaline. Merry Christmas!

Adrian Whichello                            Phone:  +61 2 351 4824
Imaging Science and Engineering Laboratory   Home:  +61 47 588 319 
Electrical Engineering, Sydney University     Fax:  +61 2 351 3847
Australia                                   Email: [email-masked]

---

From: [email-masked] (James W. Swonger)
Date: 25 Dec 1994 03:15:07 GMT

Ask for gouging rod, or carbon rod, at any real welding shop.
Don't screw around with D-cells. The rods are cheap, and they
come with a copper cladding that makes electrical contact
efficient. Try fluxing it and soldering braid, like coax
cable shield with the core removed, for a nice low resistance
electrical path.

 Gouging electrodes are also good for electrochemical machining.
Try working aluminum in a tank of brine using gouging rod as 
the cathode and a 12V car battery as the power source. Underwater
chlorine arc can really chow into aluminum. A clearing jet would
help. This is analogous to EDM but chemical rather than physical
attack. It could be just the thing for head porting work, etc.
where access in a straight line is not there; use a short 
graphite tip on a flexible wand.
-- 
##########################################################################
#Irresponsible rantings of the author alone. Any resemblance to persons  #
#living or dead then yer bummin. May cause drowsiness. Alcohol may inten-#
#sify this effect. Pay no attention to the man behind the curtain. Billy!#

---

From: [email-masked] (Colin Constant)
Date: 21 Dec 1994 17:17:05 GMT

Lawrence Boul ([email-masked]) wrote:

: of brass that require a lot of heating.  Setting pieces up to hold them  
: obviously requires some thought and wooden clothes pegs etc. don't work too 
: well!                                      ^^^^^^^^^^^^
                                  Thanks for this.  This is just what my
                                  current project has been crying out for.

Colin (now why didn't I think of that)

---

From: "Vance R. Bass, Nashville Garden Railway Society" <[email-masked]>
Date: 22 Dec 1994 04:39:39 GMT

Friends,

Vance

---

From: "Vance R. Bass" <[email-masked]>
Date: 25 Dec 1994 23:47:38 GMT

> cable shield with the core removed, for a nice low resistance

	Yup, this is exactly what I did.  The rods are cheap, but my
local welding supply shop wouldn't sell me a couple.  I ended up buying
a box of 50 for US$25, which is almost the cost of the rest of the
materials put together.  No complaints from me, though.  I took apart
a cheap soldering pencil, tapped a set screw hole in the metal barrel,
soldered the power wire directly onto the copper cladding, and snugged
the set screw.  I was in business.

	What a fabulous machine this is!  I can't tell you what a joy
it is to solder with this rig!  I used an auto battery charger for the
power source.  It's switchable to 6v/6amp, 12v/2amp, 12v/6amp.  I find
that the lowest-wattage setting (12v/6amp) will solder small parts 
and brass shaped stock just fine.  The higher settings will heat small
parts to red-hot in a matter of a few seconds!  The joints are very
clean, the surrounding material doesn't heat up much if any, and it's
fast and safe.  EVERY workbench should have one of these!

Vance Bass
Nashville Garden Railway Society
=====================================
"Remember, it ain't got a thing if it ain't got that certain
  je ne sais quoi."                     -- Peter Schickele