TIG TAWK! AC Welding Aluminum

back in my shop sweatshirt I feel my power I really should have taken some time out this summer to wash this thing [Music] let's talk about TIG welding aluminum at home I mean what we're gonna be doing here works anywhere it doesn't have to be at home but I mean for hobbyists take some of the heat off it's not gonna be rigorous TIG welding will try to make sense of all the settings and knobs you can turn and what really makes a difference in what doesn't start off really basic and then you're welcome to take it from there before we get into this I just like to take a moment to set the stage set expectations if you will there is a long list of videos on the internet about TIG welding aluminum by people who have absolutely no authority to be making such videos not formally trained or just not good at it I well I thought I'd add to that list it's 2019 and for our purposes to TIG weld aluminum you're going to need an AC TIG welder a TIG welder capable of belting out alternating current at first blush this might look complicated but let me jump the gun a bit and show you 95% of the settings you'll need to weld aluminum part of that other 5% might be making sure you're shielding gas is actually on before you jump down into the comments to tell me your great grand mom welded aluminum airplanes with a gas torch or you bought a pound of amazing a LUMO one dirt roads at the box store for your stick welder to fix your kids car seat and it's still holding great hear me out can you weld aluminum with DC TIG can you weld it with a spool gun on your DC MIG no no you can't okay okay fine maybe you can or some people can but if you're watching a tic video on this channel odds are you're worse off than me don't make life any harder on yourself if you want to weld aluminum swallow the bitter pill buy a decent AC TIG welder I know they can be expensive what is inexpensive these days but on the bright side once you learn to weld aluminum and the word gets out you'll be swimming in it [Music] [Music] I should have mentioned this earlier but this video to some extent assumes you've watched my other tig videos mechanically we're doing the same thing here as far as the motions were going through except we're dealing with aluminum and not steel but same basic steps you start the arc wait for the puddle to form add some filler scoot forward add some filler scoot forward add some filler and so on stick and move torch angle arc length keeping the filler and the shielding gas being comfortable all that jazz still applies if you can take walled steel and you have an AC welder you can TIG weld aluminum if for some reason you can't it's probably something basic that you're overlooking like not having turn on your gas I can tell you right now there are no magic settings that you're not getting right that's keeping you from welding so don't worry about settings not yet anyway I remember back when I was first learning to all the aluminum it's a phase I'm still in today and I don't know if people say this anymore but some of the older viewers might remember the popular thing to drill into new people was that welding aluminum was more difficult than steel because you couldn't see the puddle in steel the puddle turns red and molten E an aluminum it doesn't change colors so for some reason that meant it was invisible I never really had that problem sure it won't turn bright red unless you're trying to weld using hydrogen gas which you shouldn't but it won't turn bright red nonetheless you can still see it the solid turns liquid right in front of your eyes for crying out loud it gets really shiny starts to shimmy around a bit and well it's liquid fun fact if you grew up on earth most of the aluminum you'll come across in life isn't usually in liquid form so you'll probably know it when you see it personally I've always found aluminum easier to weld than steel mechanically speaking laying down the welt don't confuse that with easier to get stronger good welds not what I'm saying and steel even if it's ugly if you've used it it's probably pretty strong you know a little when I'm not always the case I'm not sure if it's the surface tension thing or the fact that aluminum pulls heat away so fast or both probably when you lay down a bead or a single dab rather the puddle tends to plump up and round itself out in fact the aluminum can prop up proud enough to fail your electrode if you're not careful with your torch or how much fill you're adding I found that surface tension to also help when you're out of position no weird upside down welds or rounded corners or something steel seems a little runny err let's put it that way that sort of self-leveling clumping rounding effect usually makes for a nicer looking beads nicer looking than and steel anyway at least for me that surface tension can work against you too however if you're really welding and not just practicing you're usually dealing with more than one part and if they're not meticulously clean you're not quick on your feet or you haven't brushed your teeth those beads can pull away from each other especially in thin parts it's really easy to do more harm than good heavens to Murgatroid am I ever getting ahead of myself I've got some strips of eighth inch aluminum about three millimeters thick a hack solved them out of my neighbors siding if you have neighbors with that cheap thin aluminum siding the best place to look for practice material is your local fab or weld shop or maybe you've got a manufacturer nearby that makes air conditioners and refrigerators if you're nice they might let you dig through their trash sure there'll be odd shaped pieces and full of holes but if you just want to practice it doesn't much matter if you're making a video however you did be crass not to shear them to a more respectable shape like rectangle [Music] I've got a 9 sighs - water cool torch with a number seven lens on it and it looks like an eighth inch tungsten probably 2% lanthanide it it's sharpened to a point I don't usually bother putting a ball on the end anymore mostly because I'm not good enough to have to worry about those details but if you like feel free I find the point usually rolls itself over fast enough on its own I do however knock any very sharp points off at the grinder if I know I'll be welding with high amperage sharp points at high amperage will auto eject off the tip of your tongue stone and embed themselves in your weld puddle which will notably lead to a failure a leak or something else not good and you may have seen it I'm using a foot pedal down under the bench that's my setup just the mood I'm in today actually just the way I left the machine last time I used it if you don't have exactly this stuff and you're about to ask if a standard 17 air-cooled torch or the switch would work the answer is No okay big picture this is an HTP 221 no lie says so right there if it looks crooked don't worry it's just the camera angle welder is doing great ten out of ten would buy again if you don't have this welder my condolences but don't sweat it layout and settings are more or less about the same on all these modern machines buttons knob settings that sort of thing in the connections at the bottom in particular there are four torch gas remote amperage control and ground ignore the shielding gas and amperage control the foot pedal for now it's not relevant to what we're talking about now you probably can't see it from where you're standing with your crooked head but the terminals on the machine are labeled negative on the left hand side and positive on the right hand side these are the large styled ins connectors there's two of them positive and negative the leads are connected as usual for TIG welding torches going to the negative side it's set up as electrode negative there's an electrode in the torch and it's connected to the negative side that's electrode negative the ground clamp is connected to the positive side again that's normal for TIG but backwards for stick welding make sure your torch is electrode negative where all the settings are about to make will be completely backwards we're in AC mode so I have access to all the AC controls we'll get to that just a second the main adjustment arguably on any well there is the amperage control amperage setting isn't really all that important since I'm using a foot pedal and can change them on the fly if I need to but if you don't have a foot pedal or a little slidy button start off maybe around a hundred amps see how that feels I'm giving myself some Headroom I don't know 140 amps but again I can adjust that on the fly as I'm welding rule of thumb if you start the arc and it's taking you 20 minutes to form a puddle your amps are too low turn them up if you start the arc and your torch and bench explode your amps are too high turn them down it should only take 2 maybe 3 seconds for the puddle to form 4 seconds is probably fine but at that point you're just being lazy the thing with amps and aluminum is that aluminum really likes to lose heat it's a great thermal conductor there is a reason heat sinks are made out of aluminum and whatever that reason is is working against you when you want to weld it when you're first starting off and the work is cold room temperature it'll probably want a lot of amps to puddle in a few seconds maybe a 120 amps to start in this case as soon as heat gets in one spot the aluminum will start to sink it spread it shut it so you've got to push hotter with the torch initially to get it to melt by the time you get to the end though the part will likely be smoking hot 120 amps we started with might be too much if you're a slow welder like I am by the time you get across this part you may only need 80 or 90 amps to keep the weld bead going I do that by letting off the pedal a bit and dropping the amps if you can't adjust your amps on the fly you may find yourself welding faster to stay ahead of the beat that or I don't know you could try blowing on it I'm exaggerating here this part isn't that big and unless you're a really slow welder it probably won't run away from you I mean in my case it's also on a 500 pound ice cold steel bench but if you notice your weld beads are getting wider towards the end or you're flattening out compared to where you started or all the single weld abs are blending into one another forming one continuous lump you've got an amp control issue or a heat issue to be more precise while other me is finishing up those welds let's get back to the machine we left all saying the torch is connected to the negative side and we're in AC mode the other two important settings arguably are frequency and balance on this machine when you hit the set AC button you light up one of those two lights depending what you want to adjust and the readout is here it's C frequency and balance it pops up temporarily and overwrites the volts and amps display in this case I'm at 70 Hertz for the frequency and it just happens to be at 78 or the balance that's 78 percent electrode negative let's talk about the frequency first I'm just gonna put it out there if you're a shade tree welder like myself frequency doesn't matter all that much set it to whatever doesn't cause you to seizure and just practice practice practice again the frequency and balance display don't last very long so it's hard for me to show you making settings on the fly but if I go to frequency it'll go anywhere from 20 it's 200 Hertz I'll just leave it around 84 now as I said unfortunately there aren't any magic settings if you're having trouble welding aluminum and you're sure you're in AC mode with the cables in the right spot it's probably something else lack of cleanliness something in your setup not enough or bad shielding gas maybe some unwell doable alloy big-picture stuff like that it's not the difference between 90 and 100 Hertz no frequency setting is gonna stop you from welding well maybe the extremes 1 Hertz and 1 kilohertz you might have a harder time but for Joe's like us frequency isn't all that important if you're a pro we're doing production welding or have some really specific combination of material thicknesses or something crazy yes frequency can make a difference that's why they let you adjust it but for me and you just starting out those are shades of gray at this point no offense intended of course I didn't mean to drag you down with me practically speaking the frequency range I stay in is usually 70 or 80 up to maybe 120 150 if I'm feeling frisky when I started out my only option was 60 Hertz so to me that sounds and feels writer for the examples you've been seeing in this video I've been at 80 Hertz but you could do 90 or 100 whatever you like it won't make much of a difference on clean metal at the pen in our nice comfy chair I mean heck we're not even technically welding two pieces together AC balance in contrast to the frequency setting if you set it too far off this could cause you some problems I mean it won't stop you from welding I don't think but it sure will make your experience less than enjoyable ac balance seems to screw with a lot of people I know it messed with my head when I first started probably no thanks to different manufacturers taking their own twist on it sometimes it's called balance sometimes cleaning sometimes penetration but it's all the same thing let's take a moment to internalize remember back like two weeks ago when I said the torch has attached to the negative side of the machine and the ground is positive well an AC welding that's a bit of a blurry line if it's an AC alternating current there really isn't a positive or a negative pole on the machine academically speaking or better yet the machine keeps switching them up when you push that AC button the machine no longer cares about the stinking labels on the terminals it's gonna start to do what you tell it to do think of it this way if you had a DC only TIG welder and you were the flash you could unplug the torch and ground clamps swap places and keep doing that 60 70 or 80 times per second and you'd have yourself an AC welder unfortunately for us however swapping cables on the fly at supersonic speeds is a fire and electrical hazard so instead people invented AC welders that do the switching for us not to mention it's hard to swap cables like that while you're welding believe me I've tried how often these cables figuratively swap back and forth is the frequency setting we just talked about again at 80 Hertz for example the torch side switches from negative to positive 80 times per second here's the thing you should know about AC welding although the terminals are switching polarities and your tungsten is going bananas switching between electrode negative and electrode positive it really just wants to be electrode negative think of your tungsten is very emo it wants to be negative for weight maybe that's goth I've lost track sure it's alternating because you asked it to and it's trying its best to play along but at night when no one is watching the tungsten lets his hair down kicks up its feet and wants to be electrode negative every time you force it to switch to electrode positive a little piece of it dies inside I think that awful buzzing you hear when you weld an AC is the tungsten swansong so if a tungsten electrode hates being positive why would we put it through such anguish well to explain that we have to talk about aluminum aluminum when it's just hanging out like this generates a very hard oxide coating basically it rusts instantly you could scrub that coating off but the second we stop bang oxide coating again the oxide layer is sort of invisible so you have to take my word for it but I'll try to show it to you later to put it simply there's an oxide layer on the surface we need to get through to weld the aluminum underneath if you try to weld through that like you would steal that oxide layer will fight you tooth-and-nail it's a near impenetrable Fortress of oxide don't despair though there's a bit of a trick coming closer as it turns out alternating the current while you weld aluminum for some unknown and/or very scientific reason can punch right through that oxide layer like it isn't even there shatters it like glass just switching from DC to AC peels that candy coating right off and we can get right down into the aluminum now you sit there look at me square in the eyes and tell me the universe wasn't intelligently designed so we've got ourselves a bit of a dilemma don't we on the one hand we need AC to break through the aluminum force field on the other hand the tungsten hates the time it spends being electrode positive if there were only some way to control how much time the tungsten is spending being electrode positive balance if somehow we can tune the Machine AC balance so we have just enough AC to break through the oxide layer but not so much that tungsten gets upset well would you look at that a balance setting on this HDPE and I think on most other socially well-adjusted welders balance refers to percent electrode negative I can set it anywhere from 90 percent down to 10 percent that means 90 percent of the time it's electrode negative or 10 percent of the time it's electrode negative it won't let me go to a hundred percent electrode negative because that wouldn't make sense that would just be regular TIG welding right it wouldn't be AC anymore I should clarify what I mean by tungsten electrodes hate being positive I mean honestly here's what the electrode hates or doesn't hate nobody really unless you weld if you intentionally force your tungsten positive or inadvertently hook up your leads backwards you'll find that your tungsten will throw an absolute fit it'll lose its point it'll split the arc will spit probably it'll get all blobby they'll generally end up looking like one of those cartoon melted spoons you won't get very nice welds with a melted cartoon spoon tungsten and you'll go through a lot of very expensive tungsten electrodes when welding an AC the right balance of negative and positive along with not dipping it in the molten puddle every 15 seconds will go a long way to keeping your tungsten and your wallet in good shape yeah ain't that a kick in the pants I don't know when you would set the balance that far down that much positive on the electrode but the point is even when you're not that far down even when you're I don't know say even 5050 the effect or the life on your tungsten tip on your electrode is cumulative you should set the balance so you have only enough electrode positive to get the job done let's see how you go about figuring out what that number is yourself this is a number six Cup the electrodes sticking out maybe a little too far but I'm running into the back half I think it should be alright let's do three quick tests [Music] this is the first one I did at 90 then 80 then 70 ignore the crooked and ugly welds that's not what I'm trying to show you it may have been smarter to not wire brush these but I think it can make my point if we start with the 70 you see that white haze the halo around the bead that's the electrode positive breaking up the oxide it's like when you step on a clear sheet of ice and it cracks and goes all opaque in particular pay attention to how wide that cleaning action that cleaning zone is if we go to 80 this is less electrode positive it's arguably a little bit thinner and if we go to 90 it's almost not even there I mean it's very thin it's just flanking the weld I did these on three separate pieces of aluminum just to try to keep the at least the starting temperature the same I maxed out the pedal I had it set to 115 amps if you go back maybe you can tell it took me a little longer to start because I had less Headroom in the pedal had less heat to start off with and you can see that particularly on 70 you see that sort of thermometer bulb at the bottom I spent more time forming that puddle at 70 percent balance 70 percent electrode negative because not as much of that AC was going into melting the aluminum thirty percent of it was going into breaking the oxide so moral of the story first if you don't do a lot of welding or practice a lot your welds don't look that great second I'm still a little upset about that broken cup and third only uses much electrode positive as you need now again these were relatively clean I did wire brush them they probably could have benefited from a wipe down with some acetone or some kind of cleaner but in this case there's no sense at welding at 65 70 75 percent balance getting all this cleaning action and just taken such a hard hit on your consumables although none of these have very much penetration I'm sure the 70% balance probably has the least there's less negative pushing into that aluminum the tungsten is doing less of what it was born to do so looking at these me personally I'd probably take a little bit more care and cleaning the aluminum before I started welding and probably set the machine to about 85 percent 82 percent although 90 looks okay the weld bead is a little bit shinier a little bit cleaner at 80% so somewhere between 80 and 90 should probably do the trick [Music] so that's 83% electrode negative I am meant to set it to 85 but you get the idea one experiments probably as good as the next I'm no optometrist but that looks okay to me I'd be happy with that one of these days I may even learn to fill my craters please don't come away from this thinking 83 is the magic number it isn't with any luck though now you know how to set your own balance again this is clean material in your laboratory settings I'm sure the flow rate and the size and type of tungsten probably all come into this too because why wouldn't it but when you have real parts to elves you might be down at 70 or 75% more you practice the more you'll develop an eye for it just starting the puddle will tell you if you're in the ballpark then tweak to taste again the goal is to introduce as little electrode positive as you need anymore and you're robbing yourself of penetration and electrode life all right well I think that's all I've got to say about that actually I could keep going but I fear I've already said too much as always I hope you enjoyed that go practice practice practice and thanks for watching [Music]

Channel: This Old Tony

Views: 946,620

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Id: 38zP4cu8kgg

Length: 23min 47sec (1427 seconds)

Published: Sun Sep 29 2019