Austin Community College (Texas) "Art Welding Course"

After about five years of soaking up knowledge from this group I
enrolled, along with my wife, in an "art welding" course at Austin
Community College.
The instructor's highest priority is to teach us to gas weld. That's
just fine with me because I have more enthusiasm for, and less
experience with gas welding, than any other process.
Our first project assignment was to weld up a cube from 4" squares of
1/16" steel.
Unfortunately, by the time we got the rudiments down, we were short of
coupons, so we were supposed to cut up some more at last night's class.
Then, on the way home, I had a blow-out on the old Ford diesel van. By
the time I got the tire changed and made it home we'd missed the class.
Not only was I tired and dirty, but my nerves were pretty frayed too.
The blowout occurred at fully 70mph on the right passenger side. It's
almost a miracle I didn't lose control.
In order to not fall behind with the class, today I cut up some 5"
squares from a 6' long strip of 3/16" x 5" material I had on hand.
This means Alma's and my boxes will be the biggest and baddest even if
they don't win "best" honors, which of course, we hope they do.
I nearly finished my cube today. To my surprise it's reasonably
square. Once I got in the groove, my welds looked pretty decent too.
Maybe after the class is over in May I'll feel proficient enough to
learn to TIG weld.
Alma is showing early promise of being the best welder in the class.
She took to laying beads like a duck to water.
So hers will probably be better.
Regards,
Vernon
Reply to
Vernon
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I visited one school where they pressure tested their cubes. I am not sure what pressure they used but a fitting was welded to the center of one panel. Some of the pieces had a nice even bulge on all the panels while other had split seams. I wondered about safety on this test but didn't ask about pressures. It sounds like you are having fun Vernon. Doing things together is nice. It doesn't work well for me. I couldn't get past the second dance class ( two left feet and no sense of the beat) On the other hand Marlene is damn handy building garages. Randy
Reply to
Randy Zimmerman
My boss at school does that with his students. He pressurizes them with water. That way there are no rude explosions, just an ocasional squirt in te eye. He had 2 russians who got in a competition. They kept repairing their cubes to reach higher and higher pressures. Eventually the winner got his to 620 psi and the cube had attained the shape of a sphere.
Reply to
Ernie Leimkuhler
It is a manual hydraulic testing pump we got from Boeing surplus. Works fine for pressure testing sheet metal boxes.
Reply to
Ernie Leimkuhler
Today I finished up the remainder of the welds on the cube.
I dumped the cube into a tub of water. Although I didn't see any air bubbles, after I took it out of the water I could hear it sucking air.
Later, I put it on a stove burner and was soon able to identify several pin holes, nearly all of which were at the corners.
Tomorrow I'll attempt to patch 'em and continue to search for holes. I thought the story about the guy pressurizing his into a sphere was really funny. Don't think I'd have the nerve to try that at home though.
Also, I attempted to lay a bed with some 308 stainless rod I bought on ebay. It is 1/8" diameter rod and I bought a shitpot of it.
What I was hoping to do was lay a bead of stainless rod on some plain mild steel. In my mind's eye I had visions of making signs that way. Glistening stainless letters on a background of rusty brown.
To my disgust, the stainless did not bond with the mild steel at all. I must admit it was a casual exercise conducted on some really rusty metal.
Nevertheless, with a no. 3 Victor tip I could not get anything that even reminded me of fusion. Can somebody tell me what should happen when you do this?
I don't know diddly about stainless. Does it require flux to gas weld?
Clueless. Ernie Leimkuhler wrote:
pressures.
attained the
Marlene is
night's class.
reasonably
Reply to
Vernon
Teh trick to gas welding stainless steel is to use a very carburizing flame. The SS rod will flow like water, but...
...the downside to this is that it will impart more carbon into the stainless steel, thereby increasing the formation chromium carbides, and therefore reducing it's corrosion resistance.
It does work though. I do it every quarter at school.
Reply to
Ernie Leimkuhler
Ernie to the rescue!
I forgot to ask about the 1/8" rod. I imagine there's a relationship between the thickness of the metal you're working on and the rod you use... But is it critical? In other words how much wiggle room do you have? I imagine that if you're welding 24 gauge sheet you can't get away with 1/8" rod but is there a rule of thumb?
Thanks!
Pulgarcillo ("Tom Thumb")
Reply to
Vernon
Don't use a filler rod thicker than your base metal.
BTW the carbon feather should be about twice as long as the inner blue cone.
Reply to
Ernie Leimkuhler
In a water-filled vessel, a simple hand pump will do this. Just make sure there's no air bubble trapped inside the cube.
Because "liquids are incompressible", you can reach a high pressure without putting much energy into it. This has two consequnces; firstly you can do it (with just the hand pump) and more importantly, a failure has relatively minimal energy to produce damage or injury.
If you want crazy hazardous, look up the Elizabeth Brim technique for blacksmithing.
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Air pressurisation of badly-welded red-hot steel !
Reply to
Andy Dingley
My dad tells a tale of the county fair as a young boy - you know - Horses were the main thing and steam engines were newish.
A man was showing the strength of boilers - after some problems were reported in newspapers -
A large box or boiler box that is - and a fire is set inside. The door closed and the boiler box soon crushed. He had earlier demonstrated the strength by various crushing and pulling apart. Simple fire burnt enough oxygen to cause a vacuum that was strong enough to pull in the sides.
What the lady did was ok - not enough pressure to blow the part apart - as it was being watched in real time. The bad ones are filling and building pressure with no stretch occurring - just pops!
Martin
Reply to
Martin H. Eastburn

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