Twin Carbon Arc Torch

Ulma Doctor

Infinitely Curious
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in high school, i learned oxy/acetylene welding and brazing operations.
when i went to community college in the late 80's, i spent 2 years and a semester learning welding processes.
gtaw and smaw. i learned a ton of stuff from a master welder who ran the program.
i would use a mig welder at work, get off work drive to school,show up early to class, and learned smaw on monday,wed
learned gtaw tuesday,thursdays. i couldn't get enough :welding:.
needless to say i got a lot of welding in and became addicted to joining metal together.
i came across a process that's very old- carbon arc welding...
i have been intimate with a gouging torch may times, but never even considered carbon arc as a welding process.
come to find out that it was first discovered and used in 1800 and is effective on ferrous and non-ferrous metals.
DCEN (straight polarity) is used.
i then remember my welding teacher talking about brazing and welding with twin carbon arc on AC.
there was 1 half page explanation of the process in our textbook and i had forgotten all about it entirely.
i recently reread some of the textbooks and ran across some notes that i had taken on the subject.
the first thing that jumped out at me was the process was extremely effective for repairing cast iron, both as a welding process and a brazing process.:thinking:
:idea:
i came to the sudden realization...
i never had the pleasure to twin carbon arc braze or weld anything:angry: this was a hurdle i had to jump,
here's why...
i recently found a deal on a complete vintage 1972 wards(century) 230 ac welder w/ a twin carbon arc torch set up complete with some electrodes .
i have an old school JET 370 power hacksaw that has some cast iron in need of repairing...:biggrin:
JETPOWERHACKSAW.JPG
the miter clamping bolt goes into a cast iron clamping plate with poor threading...
photo (10).JPG
i got lucky on one side i was able to put a stud into the clamp on one of the clamps, an easy fix.
as for the other clamp, i wasn't so lucky.
it was poorly drilled from the factory and not much of the thread profile remained.
a stud was out of the question for now...
i thought to myself, what an excellent opportunity.... to try a new old thing
i fired up my recently acquired shop oven(on casters) and preheated my damaged clamp to 300*F
jetfix2.JPG
i took out the Twin Carbon Arc Rig, slapped a couple 3/8" carbon rods cranked er' up to 90 amps and went to town on a brazing operation to fill up the hole in the cast iron. the process is slow , but, i was amazed that i didn't need flux on the brazing rod to get the puddle to stick. after a few minutes of brazing, BaddaBing ...

i put the casting on firebricks inside the oven to cool overnight.
i'll post more as i finish the repairs!
stay tuned for part 2
thanks for reading!

JETPOWERHACKSAW.JPG photo (10).JPG jetfix2.JPG
 
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You can also braze thin galvanized sheet metal together with Everdure (sp) rod and a single carbon without having the cyanide smoke release from the galvanizing.
 
i Made the brazing repair on the miter clamp with the TCA and preped the clamp for the drilling operation!

photo (12).JPG

i'll drill and tap the hole to accept a 1/2-13 stud to match the other clamp i repaired earlier.

photo (12).JPG
 
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I can vaguely remember an article in Mechanix Illustrated (I think) in the '60s that told how to make a twin-carbon torch. As I recall, it plugged into a regular wall outlet and used an electric iron as a ballast to prevent the breaker from blowing.

Might have to make one to run off one of my welders. One more for the project list.
 
thanks for the post Ulma Doctor.
OMG, you sure stirred some old memories with this one.
(look at me, typing like a teenager)
i remember in the late 60s when my house payment was $98 a month.
i splurged for a Lincoln 225 AC stick welder($104 out the door)
i found a can of 1/8" fleetweld 180 that had gotten wet, but it worked
for crude cutting of old car frames and such.(one tuff little buzzbox)
but i needed a way to heat, bend and braze. a complete set of torches was
selling for more than two house payments and i couldn't swing it.
Enter your "Miracle Tool"
Montgomery wards carried an attachment for welders called a Carbon Arc Torch
that claimed to do everything but clean your windows.
it came with a variety pack of carbons and a hand held face shield for less than $30.
bakelite handles and a sliding thumb screw to adjust the arc.
i used to light up the night skies at all hours. after a few visits from the cops and
the fire department, they told me if i was going to use that thing at night to close the door.
my paranoid neighbors never knew what to expect to roll out of my garage.
they had a huge block party when i finally moved and let them have their peace and quiet.
as they say.... the rest is history.
But i finally got my torches, then plasma. i just counted 11 of the Red and the Blue welding devices.
that old carcon arc torch is probably still around here somewhere.
thanks for shaking the cobb webs.
y'all remember what the old man said... always hammer on the cheapest part!
 
Thanks swarfed , for giving my post a read!
i'm glad it stirred up them feelings:))! here's the set up i got last Wednesday.
PK230(2).JPG
WARDSPOWER_KRAFTTCAWTORCH1.jpgWARDSPOWER_KRAFTTCAWTORCH2.jpg


just as you described!

thanks ED for the input!!!

PK230(2).JPG WARDSPOWER_KRAFTTCAWTORCH1.jpg WARDSPOWER_KRAFTTCAWTORCH2.jpg
 
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After completing the TCA brazing repair, i prepared the clamp for the drilling operation.
Jetfix5.JPG

i then tapped to 1/2-13 and cleaned the bore with laquer thinner and compressed air.
i added high strength(red) locktite to the stud before installation.

Jetfix6.JPG
JETPOWERHACKSAW.JPGJetfix7.JPG

a really fun fix, and used another process to boot:drinkingbeer:

thanks for reading, please add your comments and/or stories!

Jetfix6.JPG Jetfix5.JPG JETPOWERHACKSAW.JPG Jetfix7.JPG
 
Here is an old one I have in my collection of welding gear. The slider on top adjusts the carbon rods as they burn.


P1010040.JPGP1010041.JPGP1010042.JPGP1010043.JPG

P1010040.JPG P1010041.JPG P1010042.JPG P1010043.JPG
 
here's another example of a brazing build up of a damaged lathe compound rest.
the part will be dressed down and filed to the correct dimensions.
CRfix1.JPG
CRfix13.JPG

the process is a little tricky to learn.
the arc is very hot i've read somewhere in the neighborhood of 4,000*f and 9,000*f, dependent on amps,rod diameter, and i'm sure other factors not coming to mind.
the process is very simple and works equally effectively as an oxy/acetylene torch on brazing cast iron, albeit a little trickier due to the large volume of heat.
with more practice i'll take on other types of repairs, for now i'm concentrating on cast iron repairs.
thanks for viewing!

CRfix1.JPG CRfix13.JPG
 
Thanks to all of you. I never used carbon welding but I am impressed with the results. I used to think carbon arc was used for creating light for search lights and big movie projectors.
 
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