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Random question here... I'm playing with some aluminum. Using 1/16th 2% thoriated? (red) tungstens, running mostly about 70 amps using an old buzzbox set to AC smooth with a high freq arc stabilizer- welding aluminum.

Here are a few of my tungstens:



Sorry, its a poor pic. The left have just been sharpened, the middle obviously got dabbed with filler rod , and the right 2 are my question- they have a small ball at the end. Doesnt take long for the ball to form. Is that okay? Varying sources say the tungsten needs to be balled for aluminum, and others say sharpened. Seems like I get a more focused (read: hotter) puddle with the point, but the ball works fine as well.

Also curious as to the colors- sometimes I can go quite a while (for me) without the tungsten changing colors, other times it seems like the first weld it changes colors. Is the color a sign of contamination? Normal?

Still not pretty but I'm getting better.



Couple of shots of the welder just for fun:

Oly cow!

My dad has that exact same machine and torch.

Tungsten turning colors while welding is not enough shielding gas. The electrode (tungsten) should stay shiny in its envelope of pure argon. You should have about 15 to 30 CFH of gas to weld. Closer to 30 for aluminum.

The old practice was to use pure tungsten for alumunim on an AC sine wave machine (you have) and other blends on an inverter welder.

With pure tungsten (green paint on end) the ball will form on its own or you can make an arc on DC+ for a second or so to form it.

Its OK to use the thorated you have. It may form a ball or not. It may grow all kinds of things off the end so it needs re sharpening more frequently. If dunked (which I do frequently) stop welding right away and replace or re sharpen the electrode.

I cut the new electrodes in half and then get a short cap for the torch. It makes things easier than waving around the long back cap.

70 amps aint jack for aluminum. I think what you are doing is heating up the whole cupon then welding it. I have a tough time on 1/4" aluminum with 200 amps. Its not quite enough unless I switch to helium.

Good luck
David

Everything David says is spot on. In addition to his tips:

Your tungsten looks a little thin for alumium. I use 3/32. It should hold up to the amps better.

There's a lot of either soot or smudges on your work. If it's soot from the welding process, it's another sign that you are having shielding gas problems. What type of gas are you using? If it's smudges from your gloves, get a clean pair of gloves. Having clean work makes all the difference with aluminum.

I am wanting to be able to weld very thin (20 gauge) aluminum sheet, but practicing on the thin stuff was just driving me crazy so I went back to this thicker piece I had from a community class I took... Just using it to get the motion, puddle control and rod control down.

I will try higher amp settings. So lower amps will take longer to form a puddle but heat the whole piece up, giving me the blobby melted beads instead of the "stack of dimes"?

I am using pure argon, set to 15 CFM. Not sure what size the cup is, will check on that. Will also try higher flow there and see what that does.

I do have a 3/32 tungsten and collet, will give that a try as well.

Re- the gloves... They are the same ones my students use (7th and 8th graders) so they are alllll kinds of dirty. Been looking for a pair of dedicated TIG gloves and a TIG finger, but living in a small community makes it hard to run down to the "local" welding store... Not that I have the money at the moment to afford them anyways.

Thanks for all the suggestions!

When I'm welding alum I use lots of clamps for heat sinks and I always clamp to a backing so the puddle won't fall through. Just a hobby guy.

My tungsten stays shinny using 15 CFH. (1993 250 Syncrowave, air cooled torch)

This is thicker (1/8") so I don't have the larger backing I'd use for the thinner guages. I'd also have backing behind the corners.

We got a snow day so I went in to finish up my grades and play with my welder.

I tried a higher amperage but you can see the results... Not pretty. The one on the left was at about 150 amps, AC smooth, 1/16th tungsten and filler rod. Didn't last more than 5 seconds. The next was turned down to about 100, the next 80, and the last two are at 65. I switched to 1/8 rod on the last tungsten and managed to keep it going for a long time, although I probably *should* have changed it because it got contaminated... I did also turn up the gas to 20 CFM. I also started leaving the gas on when I was done longer to keep the tungsten cool- pretty sure that was what was causing the coloring in them.



The results. Might not look like much but it is getting better (I hope)! It can be tough welding over top of junky welds but they are starting to smooth out. Finally getting the dip/jump rhythm. The thicker rod makes it a lot easier to dip/jump for me.



I'm also starting to get the hang of telling when the base metal is too cold or hot to weld. To cold and the puddle just won't carry and the rod beads up on top. Too hot and it sinks in and looks "filmy" after it cools. Just right- you get a nice puddle that is easy to carry, the rod melts nicely, and the finished weld is nice and shiny with the "stacked dimes" appearance.

I didn't try the thicker tungsten yet. Any suggestions for welding THIN aluminum? Thanks for y'alls help so far!

I’m getting ready to buy a welder and wanted to ask for opinions on some of the different machines out there. But before I do I thought I would explain what I will be welding. I am a sculptor and while I have done a lot of bronze casting in the past and still do a bit most of what I have been doing lately is steel fabrication using 1/8” plate welded to look like large constructions with 2” plate, As you can imagine this requires a lot of lineal inches of welding very close to the edge and tons of grinding. I teach part time and have been using the school facilities but I’m getting to the point where I need to do more welding and at times other then when I am at school. I know most of what I need to weld could be done with a mig but I prefer a TIG for the control and versatility.
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The Miller dynasty 180 is an attractive looking set up and I can get one for 1952 +tax and the cost of a tank. I know miller makes some less expensive welders but from what I can tell this dynasty is the lowest costing AC/DC TIG and I do not want a scratch start DC unit. I also have a line on a pristine looking Miller 33A/BP with a water cooler, torch, foot control, regulator, ground and stinger for $1,200. I know that sounds like a lot for such an old welder but this particular unit is super clean inside and out.
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For those not familiar with the Miller 33A/BP it is a supper versatile machine and can be wired for 208/230/440 input and has an output of 465 amps, that&#8217;s not a typo, it will put out 465 amps. This is a brick shit house of a transformer welder with over 300LBS of its 850 lbs being copper. The scrap value of these things is close to 1K. I once used one of these welders to do some fabrication with ¾&#8221; aluminum plate and never came up against the duty cycle limitations. It was also first made in the early 1950&#8217;s and remained virtually unchanged up to the early 80&#8221;s when it was discontinued. Inside they are simple like a rock.
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I have a very small shop and the size of the new inverter welders is apeaing but I do not need the portability and I can find the room for the big old beast. More important is the cost and reliability.
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I would like to hear some opinions on some of the other newer welders and how they compare in reliability to the old Miller 33. I&#8217;m not hooked on miller.

You will need a 100 amp outlet for that old miller. I have used them.

They are all good. What are you going to use 465 amps on? what torch?

Find and read the power requirements on line at miller,com.

I have all inverters. AC tig IS much better than a sine wave and cheaper for electricity.

I use a Thermal Arc Arcmaster 185 AC/DC on a 30 amp circuit with a water cooled torch. I also have a Lincoln V350 DC only which I rarely go over 250 amps for tig. It has a water cooled 350 amp torch. This is on a 60 amp 220 Volt Circuit.

You will see those big ol transformer machines on Ebay for $500 frequently. Shipping not included.....

http://www.lincolnelectric.com/en-u...atters.aspx?WT.mc_id=slider_home_moneymatters


Go to this link and about half way down the page is the Square Wave 175 for $1729. You get a rebate or a gearbag of welding gloves and quickchange helmet.

I can't imagine needing 465 amps and most of what I would ever weld could be done with 270 (the medium setting on those old millers) the 220 outlet in my shop is only 50 amps but I do have 100 amps comming into the panel. I wouldn't be surprised if I never kick the breaker as it is with what I will be welding.

The welder at school is an inverter AC lincoln with an air cooled torch and I'm not overly impressed with it, but that is mostly due to the torch getting too hot to hold way before the duty cycle kicks in. I haven't had a chance to try it on aluminium.

how mucch would you expect to pay for your welder on the used market and would you feel confident doing so?

20 gauge? Have you thought about oxy-acetylene welding (or better yet, oxy-hydrogen)? You'll need aluminium flux for the process, but it will probably be easier than TIG welding something that thin. If you want to give it a try, Fornier Enterprises sells a kit with flux and a manual called "How to Gas-Weld Aluminum."


Kit: http://www.fournierenterprises.com/cart/product.php?productid=16170&cat=8&page=1
Or just the flux: http://www.fournierenterprises.com/cart/product.php?productid=17012
And there might be a new pair of gloves for sale there too

Can anyone tell me if this gas is 100% Argon or a 75/25 mix by looking at the label. I know it says Argon , but can't remember if my old bottle specified it was a 75/25 mix. This is a new bottle and just doesn't seem correct. It may just be me though.

It's Argon.
If it was 75/25 or any other mix the label would indicate what and the % of each.

Thanks fxstbiluigi
I knew it didn't seem correct.Guess a trip to the welding supply is in my future. The reciept states Ar/CO2 mix.

One tip-off is UN1006, which is the (united nations) number for argon gas: http://en.wikipedia.org/wiki/List_of_UN_numbers_1001_to_1100
The second is the word Argon without Carbon Dioxide or CO2 beside it. They gave you the wrong gas.

Yeah thats what I thought, just did not pay attention to the old tank. "ARGON" on the label with nothing else should have been a clue

you dont need gas when you arc

Takes longer to learn arc but worth it

rather change a rod size then a spool

Use my little mig 95% of the time, but have the option of arc (stick) with this old dog if need be,

I've got not exactly a welding question but you should be the right group of guys to ask.

I'm looking for a portable rig I can use for those times when I'm in the middle of tearing something down and need to get a fastener red hot. Taking a motorcycle to work's oxy/act rig isn't always feasible when it's half torn down and getting the resulting broken off bolts out has not a bit of fun.

Is a portable oxy/acetylene rig the most sensible choice? Recommendations for a red hot rig?

Why not a MAPP gas torch?