TIG time

It looks like I am going to have to buy a TIG for aluminum for my invention. I don't want to spend big bucks, and don't need anything that will do more
than about 1/4". What would be your suggestions? Lincoln 185 comes to mind, but right now, I'm not too happy with Lincoln. I know ESAB is a favorite of Ernie's, just not sure of cost. Or consumables.
What size unit should I be looking for in terms of reliability, cost of consumables, lifetime, starting cost, etc. I do like quality, and don't mind paying extra, so long as the consumables aren't really spendy for the basic stuff.
And do I need a water cooled unit, or is that something I could cobble together on such a small unit?
And then, what would be the next size up, say medium large, as I have a tendency to overbuy because I have a tendency to grow out of things once I start using them if they make me money, or I use it a lot?
Thanks.
Steve
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wrote:

Greetings Steve, Though I can't speak about newer machines I can talk about torches. CK worldwide makes very good torches. You for sure want water cooled. 1/4 aluminum takes quite a bit of power. An air cooled torch to handle the amperage will be large, much larger than water cooled, and cumbersome. Plus, you will be limited on welding time with an air cooled torch because they get too hot to hold. I finally junked my air cooled torch when it got so hot that the fumes coming off of it started to contaminate the weld. Not to mention being so hot I could barely hold it. My tig welder is an old Miller Goldstar. It works well, is pretty bulletproof, but it is huge and only has sine wave output. None of the fancy squarewave stuff the newer welders have. And those fancy features are really nice. The newer inverter based machines are much lighter and use less power so they are easier to wire up and transport. And if you can afford it buy a machine that will weld at least 1/2 inch aluminum without pre-heat. Eric
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snipped-for-privacy@whidbey.com wrote:

A used Syncrowave 250 will do the job very, very well. You absolutely want a water cooled torch as well. It seems that if you're at the right auction at the right time a Syncrowave setup can be had pretty cheap.
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Great welder indeed, seconded.
i
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Ignoramus31030 wrote:

I just used mine yesterday repairing a neighbor's floor jack. It seems the hex head that engages the handle to turn the valve mechanism had stripped out, while the socket part in the handle was fine. I took it apart, built up the worn hex with the TIG, milled a proper sized hex on it with the dividing head in the mill, then I TIG heated it and dunked in case hardening compound. Total time ~1hr working at a relaxed pace.
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And a very nice project.
i
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On 9/24/2012 12:29 PM, Steve B wrote:

Ernie's rule of thumb for initial current setup is 1.5A per thousandth of aluminum thickness. So 1/4" would be a 250A machine.
A used Syncrowave 250 is an excellent machine. That would be my recommendation as well. I had a Dialarc 250HF before that and it was a good machine also, but the square wave for welding Aluminum is really nice.
A 250A gas cooled torch has a large stiff hose and is a big torch. A 250A water cooled torch has much smaller and more flexable hose and is a smaller torch. When I changed to a water cooled torch, it made a visible difference in my work.
For cooling water, you could run full loss and just dump the warm water on the ground, or a 5 gallon bucket with the pump on top should be fine and use less water. I have built a couple of water coolers and I can't say that you need a radiator on the water return line. You do need a pump that will make 40 - 60 PSI at low flow rates. Gear pumps are my favorite.
Good Luck, BobH
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wrote:

I suppose I could chime in...
Your amperage requirement sets the size of machine.
Amperage rules start at 1 amp per 0.001" of thickness for aluminum and steel for a flat butt weld, single pass, full penetration.
1/4" = 0.250" = 250 amps.
With newer inverter machines you can cheat that a bit using a higher output frequency. Transformer machines can't do that.
A 250 amp machine is going to be your minimum. A used Miller Syncrowave 250 or Lincoln Squarewave 255 would work fine as long as you have the power to feed it. My Syncrowave 250DX has a dedicated 90 amps circuit of 220 volt single phase. An inverter based machine will pull considerably less power from the wall, but they cost a lot more.
Miller is bringing out a new Dynasty 250DX this year. The Dynasty 300 was replaced with the 350 and the price stayed up around $6000. The Dynasty 250 is supposed to be around $4000. The Dynasty 200 runs around $3000.
You can find older transformer machines, but with aluminum you need good AC and a good high frequency unit and the high freq's get less dependable as they age. Also a big 400 amp transformer machine will need at least a 120 amp circuit.
Is there any way you could Aluminum MIG weld the part? The machine would cost considerably less, if it would work for your application.
Also for aluminum you really need a large water cooled torch. A CK 230 Flex head would be my first choice.
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wrote:

I have yet to see a picture of what you are doing.
Miller and Lincoln both have small spoolguns out that work pretty well. For aluminum you need a 220 volt MIG for any real work.
Lincoln does have a tiny spoolgun that actually does work on their 110 volt MIG, but it is limited to 1/8" aluminum.
For 1/4" aluminum you need to be in the 150 to 200 amp range, at least, for a MIG.
That means the 220 volt "baby" MIGs or the smaller roll-a-round units.
So on the Miller side you have the Millermatic 180, 211 or 212, or the inverter based Passport Plus or Multimatic 200.
All of these can use their small spoolguns. The Spoolmate 100 works with the Millermatic 180, and Passport Plus The Spoolmate 3035 works with the Millermatic 211, and Multimatic 200 The Spoolmate 200 works with the Millermatic 212.
You can go pro level and get a Millermatic 252 with a Spoolmatic 30A, but that starts getting pretty pricey again.
Lincoln has a similar lineup.
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wrote:

At least give it a try. It could save you a lot of money. You will need to sacrifice a bunch of metal to get your machine dialed in to your weld requirements.
When you get a setting that works, write it down. Aluminum MIG is not like Steel MIG. With aluminum you have to set the machine precisely to what you are doing.
You have a choice of 2 wire alloys. 4043 is a better color match for 6061, especially if polishing or anodizing. It is softer, and more shock and heat resistant.
5356 is a better match for 5052, and other marine grades of aluminum. It is stronger, and more corrosion resistant.
Use pure argon or argon/helium as your shield gas.
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wrote:

Stick with 5052 sheet and 5356 filler wire. You will need to isolate the aluminum from the steel, with a rubber or plastic gasket and plastic washers on the bolts, or you will get accelerated corrosion.

You will need to dial the machine and wire down. You will be running in "short circuit" mode, and the arc should sound like steel MIG.
Again you will need to run test welds to get the settings right.

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wrote:

Depends on who used it. A lot of people buy them because the sales guy pushes them, but they end up never using it.
If it is in good condition, used is fine.
There are 3 transfer methods with aluminum. ----------------- Globular is low voltage, low wire speed
Sounds like "pop pop pop". Useful for filling in holes and working near edges, but looks kind of lumpy. Acts almost like TIG welding. ------------------ Short circuit is low voltage, medium wire speed.
Sounds like steel MIG or tearing heavy canvas. Makes a weld similar to steel MIG, the most common methods for welding thin sheet. ------------------- Spray is high voltage, medium wire speed.
Sounds like a high pitched hum with a hiss. The most common process for 1/4" aluminum and above. High speed, but also high heat. --------------------- Short circuit and globular usually have the tip flush or slightly proud of the gas cup. Spray has the tip recessed inside the gas cup to prevent the end of the tip from melting. Spray eats more tips than any other process. Copper and aluminum can melt together to form aluminum bronze.
Keep your wire trimmed close to the tip, and keep your nozzle clean so you don't lose shielding gas coverage.
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message wrote

There's one more method making it four. Constant current. Used with large wires. Very hot but really lays down metal! We used a King Cobra water cooled gun powered by a Lincoln DC-600 with 1/16 wire at 350 amps on 1 1/2" 6061. The Anderson brothers from Traverse City said we would be told that it would not work but believe me it worked a charm. Deposits were clean as the wind driven snow. We ran all the qualification tests and finished the job under time routing. The company hired a new 'welding engineer' and the first thing he wanted to do was throw out this procedure! We had to convince him otherwise. Made a believer out of him... ;>)} phil k.
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I think that is spray. This is from the Lincoln web site.
Power-source selection: When selecting a power source for GMAW of aluminum, first consider the method of transfer -spray-arc or pulse. Constant-current (cc) and constant-voltage (cv) machines can be used for spray-arc welding. Spray-arc takes a tiny stream of molten metal and sprays it across the arc from the electrode wire to the base material. For thick aluminum that requires welding current in excess of 350 A, cc produces optimum results.
If you think about spray arc welding, the use of a constant current power supply makes sense. The wire is not contacting the work. So it makes sense that the current ought to remain fixed.
I had a friend that had a 110 volt mig welder and a AC/ DC stick welder. He was not a proficient welder so when he needed to weld something that was too heavy for the little mig, he would disconnect the mig power supply from the wire feed and connect the stick welder to the wire feeder. So he was using a constant current supply. I thought it would not work, but he insisted it did and I later figured out that he was operating in spray mode. I have tried it and it does work.
Dan
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