Tig welding aluminum, water cooled torch or not?

Air cooled torches will produce good welds, just not as much at a time. The torch will tell you when to let it cool down. If it is in class, just bump up the pre-flow and post-flow. Just kidding. That wastes gas. Beads slumping because they get too hot usually happens in class when putting down stringer beads on a single coupon. Grab a few, and alternate. Remember that the aluminum oxidizes a bit as it heats up, so a quick swipe with the stainless brush before moving on to the adjacent bead helps. Also gives the torch some time to cool down. I've only needed a water cooled torch once, when I was building up an area. I bought one, and a larger welder, but have not had a project that required it yet. If I had just calmed down and watched some birds, everything would have been fine. Most of my work doesn't need a water cooled torch.
 
Take the pulse off and set the amps to 200A. To prevent the piece from getting heat-soaked and sunken-in (to some degree) at the end, you need to outrun the heat flow gradient that you cannot see that is warming up the piece the moment the arc is initiated. The only way is to use a lot of initial amps, get the puddle going in about 2-3 seconds max, and then move and taper off as needed. Sitting there at only 130A will only warm up the part first, and then you are at the mercy of the overly-warm part. Subsequent beads should be done only after the practice piece has cooled, otherwise, you are once again at the mercy of the warmed piece, which introduces another variable you aren't ready for. If your torch can handle the heat (and your hand) then going to a water-cooled torch will not cure a welding knowledge/technique issue. It will however provide more comfort for you since the torch will heat up less, and the tungsten may retain more of it's initial grind because it is running cooler. If you plan to do a lot more aluminum, you will inevitably desire a water cooled TIG torch, IMO. I say get it now and be done with it. You already sourced the torch and pricing, so just take the plunge. It will not solve the knowledge/technique issue, but the added comfort is a tremendous advantage.
 
General Zod has an excellent point in regards to "sitting and warming up the part." When I first started to TIG weld I was 'afraid' of too much heat in the part so I started my welds with a gentle ramp-up with the pedal. What I ended up with was a mess. I had too much heat in the part and my bead was just garbage. I asked the instructor about this and his response was "stand on it", meaning don't be shy with the pedal and get the weld pool started immediately and get going on the bead. Once I started doing that my welding improved dramatically.
 
First, stop using a grinder/flap wheel to clean your aluminum. Only use a stainless brush and it has to be dedicated to aluminum only. The problem with grinders and aluminum is that it will leave silica in/on the aluminum. Aluminum is very fussy about surface contamination and lack of shielding gas. A lot of beginners (I am also an amateur) don't realize that you can have the best gear and very often the weld will still get contaminated by air (or anything else) penetrating from the back side of the weld so anything you can do to minimize contamination on the weld area (ie: no flap wheels, no sandblasting, no etc) is well worth the effort.

I have an Everlast 250. Came with a water cooled torch. Anything over roughly 125-150 amps you need to start looking at water cooled torches. Get up around the 200 amp mark for any significant amount of time and water cooling isn't an option, it's a necessity. With aluminum, you're over the point where you should be looking at water cooling nearly 80% of the projects you will do, unless you only work with thin sheet or maybe stuff in the 1000 alloy group.

Sure, the torch gets hot to hold without water cooling, but it's more about not having the heat damage the torch itself. You can get air cooled torches that are good a bit over over 125 amps, but that's not your average torch. If you had one, you'd know it because they're not cheap.

Aluminum welding is learnable (even fun), but a good part of it is experience and perhaps a bit of intuition about what you need for settings.

Aluminum takes a lot of amperage to get it started, I'm usually starting no lower than 150 amps, even for the thinner stuff. You have to get it clean and then hit it hard to get it flowing.

When I say “hard”, I mean every single amp you have dialed in, full press on the pedal. Thats where the phrase “stand on it” essentially cones from with regards to tig.

Once you see a puddle form, you need to back off the amps or it will turn into a big liquid ball on the floor (or burning through your boot!). It's a bit of a balancing act between how fast you feed the rod and how much you feather the pedal, all determined by what you are observing at the weld puddle.

Experience is key here as you have to develop an "eye" for whats a good puddle and how to control it. Feeding rod cools the puddle, so you may find you have to give it a bit more once you're travelling, but you also have to watch the puddle and back off the amps if you see it getting too wide or fluid (ie: about to form a puddle on the floor). I can't really describe it, you just have to develop the "eye" for it. For me, it's a never ending back and forth between the pedal and the rod feed to keep a stable puddle and flowing well. Generally, I often see a change in the “texture” of the puddle, which tells me a lot about too hot, too cold, contamination, etc.

My 250 runs a bead in aluminum no problem. I've done everything from 1/8 sheet to big old nasty castings. the Everlast never skips a beat.

I would recommend switching out from the stock torch collets to a gas lens. It cost a couple bucks more, but it gives you much better gas coverage and makes getting a good bead running much easier for a beginner. I also find the larger gas lens cups make it easier to see whats happening at the puddle. You can even get glass cups so you can see everything happening at the business end of the torch.

There's so much to know about tig welding aluminum it could fill several encyclopedia sized volumes. Your classes will give you a good start on the basics, then you start building up the experience base. I find its as much a craft as it is a trade. Trades you can learn in school/class, a craft you have to learn the fine details through time/experience.

Good luck.
 
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You can get air cooled torches that are good a bit over over 125 amps, but that's not your average torch. If you had one, you'd know it because they're not cheap.
The TIG torch that came with my Lincoln is rated for150 amps, and I have routinely run 200 through it for short runs.
 
Experience is key here as you have to develop an "eye" for whats a good puddle and how to control it....... I can't really describe it, you just have to develop the "eye" for it.

I agree with developing an "eye". You described it as best as it can be described in words/text. In other words, one simply has to learn how to weld. :)

The only part I disagree with is just sorta based on a technicality with regards to when one needs to consider water-cooling as a necessity. I'm sure you know that 26-series torches are rated to 200A, and the good ones are 100% duty cycle if you can withstand the heat in the torch body. There is also the Heavy Hitters TIG Torches. Their big boy torch is rated @ 350A with their special cable assembly, or a standard cable assembly with a 1awg cable. A friend of mine tested it, and according to him, the "real world" capability is around 300A, which is still pretty impressive.

Here in this pic, From Left→Right, you can see a basic cheapie 17-series, a CK 17 series, a basic cheapie 26 series, and the HH350 HD. It is massive in both size and weight. Almost twice the mass compared to a cheapie 26-series (131g vs 228g)

uc



Part of the reason it is rated very high, aside from the mass, is due to the argon port. It doesn't simply come into the torch head from the bottom like all other torches. Instead it is routed around the torch head and the argon is delivered from the top of the torch head. I'm pretty sure this provides better cooling.

uc



Of course it has it's place, so I'm not saying it's the best choice for all high-amperage welding w/o water cooling. But in a pinch, when you can't take your water cooler out to a mobile/remote job, one of these could potentially get you the extra work. Couple it with either medium or Large Gas Lens collet bodies for even more added mass to help absorb heat, and there is your forearm workout for the day. Just throwing things out there for the community. :)
 
That was really good info General Zod. Thank you for that. :cool:
 
Okay, there are quite a few things going on here. For reference, I have an Everlast PowerTIG 210EXT and a Miller Syncrowave 250DX TIGRunner so I'm pretty familiar with both style machines.

Let's back up a bit to talk about the variables for AC aluminum welding. Amperage is obviously the primary variable...more amps equals more heat, but other factors come into play as well. For machines with a variable frequency, the higher the frequency, the less heat goes into the work and vice-versa. Pulse also puts less heat into the work, which is why it helps on thin material. AC balance is primarily about cleaning action, but also does affect the amount of heat in the work....more EN puts heat into the work and more EP puts heat into the tungsten.

Also, post-flow is important to cool your tungsten. If the tungsten doesn't return to it's normal color you need more post-flow. It will prevent the tungsten from balling as much, splitting and growing nodules.

With the Everlast there are more things you can set, so more things that can cause issues. You said you're running pulse, but didn't mention the AC balance or frequency the machine is set for.

The Syncrowave is fixed at 60hz for frequency, most don't have pulse (it's optional) and the pulser is pretty limited. You can set the AC balance just like with the Everlast.

With the Everlast, if you have the frequency set higher than 60hz, it puts less heat into the work for a given set amperage on the panel. Running pulse puts even less heat into the material for a given set amperage. Combine those two things, and it's very possible you're putting quite a bit less heat into the work with the Everlast than the Syncrowave. Now, you're going to say "I'm putting less heat in, why is it melting?" right?

Less heat input means you have to go slower, and the longer total arc time means the work gets hot. Run one bead and it's okay, but start a second and the work is already hot, so it quickly overheats and melts. I like to keep two or three pieces on hand, and rotate them between each bead. If I'm really practicing hard I'll keep a small pail of water and cool the pieces every couple of beads.

The normal rule is roughly 1A per thousandth of an inch of material. So, for 3/16 you'd want to set the machine for something in the 175-200A range as a max. You're only going to use the max to get a puddle, and back off from there. More heat up front will get a puddle faster and put less heat into the work than creeping up on it.

Turn off pulse, set the frequency to something in the 60-100hz range, set the AC balance to 20% EP, and whatever post-flow keeps the tungsten gray. I can't recall, but I think Everlast does their AC balance opposite of the Miller, so just check that you're at 20% electrode positive.

Give those settings a try and see what happens. Just rotating the work will make a big difference on aluminum.

For a number of reasons I won't go back to an air-cooled torch. The WP-20 torch that's good for 250A is the size of a WP-9 (125A) air-cooled torch, so you get the best of both worlds....small so it fits in tight spaces, light and easy to hold steady, and shouldn't get any more than just a touch warm even when run hard.
 
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I'm not surprised that you find welding to be a pleasure with the Syncrowave (and, therefore, Dynasty as well) welders. They have sophisticated pulse and stitch modes that drastically reduce the duty cycle of the torch and machine. As far as I am concerned, these are the best welders out there. I don't have much experience with these new, imported switched-power suitcase welders that everybody is touting these days, so if they are where it's at, then I've missed it.

The normal Syncrowave models you run into like the 250 and 250DX don't have sophisticated pulse or stitch at all. Pulse is optional on both of those models and it's very limited compared to something like a Dynasty.
 
In my view, a water cooled torch is the way to go. I have a syncrowave 351 and a lincoln 200. The 351 is water cooled and the lincoln isn't. The torch on the lincoln gets hot quickly, and it really kills your rhythm having to wait for it to cool down. It's almost as bad as reaching the end of the duty cycle.

The syncrowave performs better in general and I've never had to wait for anything. I don't use pulse with either machine, preferring to pulse with the pedal. I can change the frequency on the lincoln which helps in cases where I need a really tight arc, but in other cases it's useless and serves only to produce substandard welds.

I can weld just fine with the lincoln but prefer the miller any day of the week, from welding sheet metal to 1/2 aluminum. There is a difference in arc for sure. The miller is more aggressive and with power to spare, I can get a puddle almost instantly with thick, cold aluminum. It's a pleasure to weld with it.

But my point is that no two machines are alike. You have to learn how to weld with each of them. The principles are the same, but not the welders, and some welders are easier to transition between than others.

I found early on that setting the amperage about 10-15% higher than the work thickness helps create a more consistent bead. You can push down on the pedal to get the bead started quickly but don't have to pull back as much once you get moving. Setting the amperage too high and having to back off a lot kills consistency. Plus, if you sneeze or twitch, that pedal gonna go to the floor and there goes your nice bead. :oops:

Bear in mind that, as you weld, the material gets hot and needs fewer amps to advance the puddle. You have to back off on the pedal or speed up the bead. I prefer to back off on the pedal as it give me more control.

I also use blocks of aluminum or wood to support my hands when I'm welding on a bench. Sometimes I need support only on my "torch hand," and sometimes both. Also, concentrate...on...the...puddle. Adding filler rod will become second nature with practice. So, will your torch control.

Try to keep consistent with torch height. I tend to weld real close to the work, which is fine with steel. But, with aluminum, you have to move the torch back much more when adding filler rod to avoid dipping the electrode in the puddle. The higher the torch height, the more you have to drive the pedal.

Keep at it. Tig is an artform and it takes a long time to really get good, but it's so worth the effort. Once you reach a certain point, you will be able to weld anything and not doubt yourself for a minute. It's hard to describe other than to say that it's a liberating feeling and opens the door to possibilities you never dreamed of, whether it's making simple repairs on the spot or fabricating intricate parts. It's an awesome tool.
 
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