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Henshao
| | Posted on Monday, April 11, 2016 - 05:47 am: | 
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Just to chime in on a tangent, but all it takes to make hydrogen is water and electricity. You'd think that private, on-site hydrogen generation wouldn't be too large of a hurdle; there have to be paintballers and scuba divers that compress their own tanks. |
Reepicheep
| | Posted on Monday, April 11, 2016 - 08:01 am: |
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I think the compression of the hydrogen is a bigger issue than the creation of the hydrogen. But I suppose it might not have to be compressed if made on site. |
Etennuly
| | Posted on Monday, April 11, 2016 - 01:45 pm: |
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Tonight, I couldn't seem to get it despite heavy use of wire brush, playing with settings, turning up the argon flow, etc.
Maybe it is not really aluminum. Or perhaps too much alloy metals in it. Cast aluminum can be mixed with magnesium, like in cast wheels, and engine side covers and such. That takes different alloy wire or rods. |
Thumper74
| | Posted on Monday, April 11, 2016 - 05:03 pm: |
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I used to work at a shop doing custom driveshafts and always heated up the aluminum with a torch first... |
Sifo
| | Posted on Monday, April 11, 2016 - 10:43 pm: |
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Just to chime in on a tangent, but all it takes to make hydrogen is water and electricity. You'd think that private, on-site hydrogen generation wouldn't be too large of a hurdle; there have to be paintballers and scuba divers that compress their own tanks.
Not sure where you were heading with this, but paint ballers generally use CO2. Divers generally use plain dried air. The equipment for dive tanks is very expensive. You not only need to dry the air, but compress it to around 3,000 PSI. Contamination with oil is a huge no-no. Specialty mixes with helium are used in advanced deep water diving. Not the stuff of typical sport divers.
Doesn't magnesium have a habit of catching fire when welded? |
Henshao
| | Posted on Tuesday, April 12, 2016 - 10:36 am: |
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In regards to the question of why atomic hydrogen welders fell out of favor. |
Etennuly
| | Posted on Tuesday, April 12, 2016 - 12:45 pm: |
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I poked a hole in a side cover on a 1973 Honda XL 250 many years ago. The guy who welded it tried aluminum TIG but it was no go. He said too much Magnesium in it. Switched to a special filler rod and was good to go.
Magnesium will burn if it is more pure than the aluminum alloys that I have seen. |
D_adams
| | Posted on Tuesday, April 12, 2016 - 01:29 pm: |
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Try this chart for correct selection of what filler material to use.
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Zac4mac
| | Posted on Tuesday, April 12, 2016 - 09:56 pm: |
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In regards to the hydrogen welder, the H2not only shields the weld from oxygen but it boosts the temp by dissociating the H2 to H+ then recombining.
Water torches are neat, I played with one at one of my past jobs.. nowhere near the output of the GE torch.
Seems that I remember it being similar to a MAP torch.
Not even as hot as Oxy-Acetylene.
Z
Oh and as to why they fell out of favor..
The transformer weighs around 600lbs and it's a LOT more awkward than a modern TIG.
As for the hydrogen supply, the torch takes 10-12psi to run.
(Message edited by zac4mac on April 12, 2016) |
Mrlogix
| | Posted on Wednesday, April 13, 2016 - 03:18 pm: |
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GE Atomic Hydrogen welder
two words- Hydrogen Embrittlement |
Fast1075
| | Posted on Thursday, April 14, 2016 - 04:21 pm: |
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I HATE welding with 7018 overhead. I get too much in my shirt pockets. |
Ourdee
| | Posted on Friday, April 15, 2016 - 09:37 am: |
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Harry, I was going to talk about the leather half top jacket and my green jacket with the pockets on the inside that I use for overhead welding. Then I saw you were in Florida. Too hot to wear any extra stuff down there unless it is winter. Only suggestion I have is to turn your jacket inside out and hose it down with cold water. =] |
Fast1075
| | Posted on Friday, April 15, 2016 - 02:16 pm: |
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I wore sleeves to keep molten chunks from getting against the skin on the insides of my elbows, and a drape over the helmet to keep them off the top of my head.
I had a few good ones. One burned thru the drape and lodged between my glasses and my upper cheek, just below my right eye.
Had a few somehow make it into my boot tops. And some get thru the shirt and get caught by my belt. (I was young and skinny then). Nowdays my belly would defect anything long before it ever reached my belt. |
Etennuly
| | Posted on Sunday, April 17, 2016 - 07:14 pm: |
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I frequently repair and weld aluminum top frame rails on box trucks and trailers. The two inch top edge where the roof skin will attach, will get bent down from rubbing on tree limbs or low buildings and such. It will crack the two inch edge loose from the extruded rail causing a leak.
This repair usually requires heat annealing to get the rail edge straightened, shrinking it, and then cleaning and welding it, back up under the top edge. Many times they would be split for eight feet or more, they got welded solid for the length of the break.
A while back I was told by a major rental truck company that I was one of three, of several hundred nation wide box truck repair vendors, who could do the lengthy upside down weld on the extruded aluminum top rails.
I used a leather welding jacket on backwards when welding aluminum upside down twelve feet up. I had a quilted jacket that I wore under the welding jacket that caught on fire more than once. The quilting insulation kept me from feeling the heat for a while. Once, it burned through to melt into a sweat shirt I was wearing under it.....hell of a fire. One of my guys douched me with a water hose on a cool day when I did not even know I was on fire. What a cold rush!
I hate those mini sparks that bounce around and end up in the ear. Also I have had people grab my welding gloves to pick up and carry stuff. What a surprise later when a finger seam is unknowingly split and weld sparks get in a glove.
The sacrifices and the things we put up with for our jobs! |
Aesquire
| | Posted on Sunday, April 17, 2016 - 08:09 pm: |
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Some aluminum alloys won't weld. 6061 welds nicely, but 2024 just won't... you might think it's welded, and it cracks. Friction welding is the only way I know to weld 2024. Million rpm ball..... Developed by Chrysler back before WW2 IIRC.
Safety tip for welding. Leave your Bic or other butane lighter in the locker room... or another room. Slag will set one off. The hot stuff will get into jeans pockets you can barely get your hand in.
I'm mediocre at best with a welder. Lack of practice. But I hear some good advice here. |
Ourdee
| | Posted on Sunday, April 17, 2016 - 09:06 pm: |
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At work there is a fire-watch person required. I learned to brief them ahead of time that they are not to hose me down. Just pat the fire out with out saying anything. I don't want to be disturbed while stitching the thin stuff back together. |
Torquehd
| | Posted on Monday, April 18, 2016 - 01:10 am: |
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What process are you guys talking about? |
Etennuly
| | Posted on Monday, April 18, 2016 - 12:02 pm: |
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What process are you guys talking about?
I weld aluminum with my Miller Matic 250 MIG with a spool gun using a 25/75 argon mix. On a top rail that needs a long weld I start in the middle with a tack weld then go to the middle of each end, then split the distance between them and so on until I have tack welds every inch inch or so. Frequently I have to partially quench areas of the tack weld areas to keep heat stretching under control. Then I go back and weld the spaces between the tacks, again starting in the center and working back and forth end to end. I do several welds then stop for a while for it to cool naturally. I might weld and stop, letting it cool like this, five or six times on a weld over say eight feet or more.
I always keep a 2 gallon bucket of water within reach of me, a water hose turned on and at the ready, and a five gallon bucket of water nearby, and extinguishers where they should be. It is so much easier to put out a fire just as it is starting.
As a safety habit I don't leave my shop welding area for at least an hour after welding. Welding at twelve feet above the ground presents a lot of showered sparks that can roll into places you forgot were there. |
Ourdee
| | Posted on Monday, April 18, 2016 - 01:20 pm: |
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+1 what Vern said. I also keep wet rags handy and put them on stuff ahead of time, like inside the body of the vehicle where the foam is inside newer cars. I split the difference when stitching to keep splits from opening up, or going all wonky. Not letting the heat build up on thin stuff is key. |
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Filler rod selection