Expert alloy tig welders. I need advice

[yoeddynz]

I am struggling at times, in fact most of the time, welding alloy. I realise its early times yet and practice practice etc but a few answers and a bit of advice can go a long way.

I am using Zerconiated tungsten electrodes. 2.4mm and most of the alloy I am attemping to weld is between 2 and 5 mm thick.

I cant find a definite answer as to how I should grind the end. ie pointy like a pencil, a shorter 45degree point, a point with the end flattend off, or rounded off. Its meant to form a ball? but I have yet to see that happen.

Clean width setting- I have read up and watched all the excellent videos from welding tips and tricks etc. I understand what it means but not sure still about the settings on my welder.The instructions supplied don't make perfect sense It has 30-80% clean width and states towards 80% is more positive electrode. That means less cleaning right? Certainly I can see the surface 'dance' when more electrode negative? I think in the middle is 50%. What setting should I start in for pretty clean alloy- 60%?

If I touch the work piece or touch the electrode with the filler rod its all over. the work piece goes dirty black and the arc gets all unhappy like, flicking all over and really big. Plus it gets louder. I usually just change the electrode straight away but have noticed that if I do continue past the affected

area the tip seems to self clean? should I continue or just change the electrode- what do good welders do (except 'not touch the workpiece'..)

Alloy doesn't flow like steel. If I get a pinhole appear I can seem to just go back over it without filler and smooth it in like I can steel.

Gas flow- if too much does it affect my arc. I the think the regulator I have is a bit shit. Its a strata item and I cant get it to flow less then an indicated 4-5 L/min and then it pops off. I don't think it reads accurately. I will take it back. Someone said that I should only just be able to hear the gas. I think it flows too much and the gauge is wrong.

If the alloy gets too hot it goes sort of mushy, grey colour. And the arc seems to become less stable? I have to learn better foot control on the pedal, which btw seems to have an overly strong return spring.

I'm sure I'll have more questions soon but for now that will do..back to the shed and continue making a mess. At least I can grind and file neatly.....

[Llama]

with alloy you want a balled end. run it reverse polarity on some scrap for a while to ball it. too much gas will give you a hard arc I'm pretty sure.

else evil_si probably knows the rest

[yoeddynz]

I reckon I need to seek an local expert alloy welder and get some one on one action going on. A guiding hand. Someone to show me how to handle my rods.

[flyingbrick]

Iv only done alloy a few times but number one lesson was that everything needs to be cleaaaaaaan.

Wire brush the shit out of where u are welding

[DodgySam]

OK...Tungsten, sharpen it to a point...doesnt have to be like a pencil but to a point.

Wire brush whatever ur about to weld right before you weld it as ali corrodes in about 20mins.

Make sure you use a new (preferably stainless) wirebrush that hasnt been used on anything but aluminium before.

Before you start get REAL comfortable.....try sitting if you can.

TIG welding takes concentration so be somewhere quiet and well ventilated and just stick with it.

It took me aaaaaaaages to get the hang of it but when you do you will get the biggest grim when ur done.

[Mattt]

I assume your meaning aluminium? No, you don't sharpen it. As said before to form a ball put it on dc and and run it for around 1 second then it will form a ball and you can switch back to ac. That's the best point to start from. Also you will find with ali you need to move quite a bit faster, as the ali heats up you will want to back of the pedal to compensate. Also I reccomend welding the last bit first so that as you are welding the last bit it doesn't open up from the heat. Its a bit of a bitch but practice and setup is everything.

Also I'm not an expert but I am trained and practised.

[Mattt]

also as far as the touching it goes then yes it wil do that. Try not to touch it obviously but if you do then do the dc electrode negativ thing so that it cleans the tungsten and forms the ball again. If welding 2mm ali you will want it on roughly 70-90amps and starton around 50/50 cleaning I think. Its been a few months!

[Yowzer]

Wow, this sounds like all sorts of complicated.

I want a TIG!

[Seedy Al]

haha me two

I am following this closely

[Llama]

Wire brush whatever ur about to weld right before you weld it as ali corrodes in about 20mins.

You don't need to wire brush the oxide off if you are welding with a AC tig, just make sure the filler and work don't have oil and stuff on them. Isopropyl alcohol and acetone are good cleaners that won't kill you when you weld them.

When looking at your AC balance (the 20-80% or whatever you have) setting, you should be able to see a small clean area around where you weld, like the lightened area below. If you have the clean area too big you'll make a mess of the tungsten, and lack penetration. If you can't see it then you've probably got oxide inclusions in your weld.

[cute wee gem]

Mushy grey sounds like wrong polarity or not enough gas IIRC (could be wrong but I taught myself and have been through all this shit)

That DC electrode trick sounds awesome though, never heard about that in my readings!

[Mattt]

I had an extremely experienced tutor which taught us that. Dc electrode negative, quick squirt on the gas and shes good to go. Also just thinking about the balance of cleaning to weld or whatever it is i think the welders i used had a balance position on them so it may pay to disregard my comment on 50/50 balance.

[evil_si]

I linish my tungstens to a point, they soon ball when your welding,

I find Most ali is clean enough to just weld without cleaning up, scotch brite is excellent to clean alloy

When you find settings that work, make a note of them, even better find someone with the same machine and pinch their settings

My tig is digital, fuck knows what each setting is, i just know what numbers should be in each box

[yoeddynz]

Sweet guys, late reply on my behalf but yeah some goods tips there. I'll post up some photos in the morning of welds and problems.

Cheers.

[Stu]

A 2.4mm tungsten is perfect for those thicknesses - you can go up to the 3.2's for heavier plate if your experiencing alot of tungsten degradatuion but most of the time you should be fine. I've tired lots of different tungsten prep methods and found that grinding a bevel and leaving a small flat section ~say 1mm on a 2.4mm tungsten will form a really nice tip once you start. It will eventually form into a ball but I find that you get cleaner welds when starting out and getting the plates hot with the bevel - a ball is fine once everything is rosey. Stick out depends on the position your welding but usually I have about 3-5mm protruding.

Cleaning wise I tend to set mine to around 60% but it does depend on the grade of ali that your welding and I've found this varies hugely between machines as some are build way better than others. The Lincoln Electric 205 inverters needs way less cleaning than the other machines. I can't stress enough that clean ali makes all the difference and I tend to use IPA for a gentle clean prior to welding but I never wire brush as this generally raises a gritty surface which can contaiminate the welds.

As you say, try not to touch the work piece but fairly inevitable that you will. If you do you'll find after the big smoke out and you've coughed your lungs clean again that if you keep the arc going on the spot but back off on the pedal a bit it should clear and off you go again. You will need to clean away the smoke debris that circles that spot on the weld. Its a bit of trial and error getting the right amount of amperage to keep the arc going (which will clear the weld) without actually continuing to weld or making holes etc. You shouldn't have to clean the tungsten each time (you can if you want) as it'll clear itself as you go. Again just try not to - you can reduce the tungsten stick out to help avoid it but you'll need more grunt to offset.

Gas flow is a hard one - I tend to er on the site of caution and use more than required but thats cos I 'aquire' argon and try not to pay for it. I have found that by not only adjusting the flow (6-7 seems to pretty good) but also taking the little cap off the regulator and winding that back with an allen key when the bottle is full (need to adjust back when the bottle is nearly empty) you can save alot of lost gas as you tend to get a big hit first that then backs off. It all depends on what your welding - with pipe I tend to purge first and same with capping RHS etc.

As the dodgmyster sam wrote above - get as comfortable as possible and seated is best. Try and rest your arm or wrist on something while you get the hang of it - it makes ALL the difference. I'm no expert but have been welding for about 10 years and its an ever evolving skill. Back when I was welding every day I could weld .9mm sheet without too many issues (actually .7mm at times but not often) - haven't welded anything less than 2mm lately but still seems to be ok.

Alot comes down to the machine - the Lincoln has a water cooled torch and everyone who has had a go can't believe how well it welds.

/rambling

[Steelies]

^ agree with all that, especially tip bevel, comfortable positioning (including mimicking the weld path to make sure) and hygene. also check tungsten hygene and contamination by linisher/grinder. we have a dedicated stone for tungsten sharpening

[yoeddynz]

cheers stu for all that info. Yeah I have tried the sitting down but right now in my tiny shed I cant sit down at the bench as there is no room underneath for my legs. So standing it is. I do lean against the bench and try to rest my arm or hand on something. I have started to either wrap the torch lead one turn around my arm or hang it over my shoulder to take the weight- its quite a hefty thing if left hanging. I spend a bit of time evaluating where my hand needs to move etc and get in a position that allows free easy movement without having to stall.

I am still putting a point on the tips and it does form a tiny little ball if I am lucky enough to give it enough time. usually I have touched the job before then...

I noticed that it does sort of self clean if I have only lightly touched the work piece.

I think my reg is shit and flows too much- should I be able to hear the gas flow from half metre away or only hear it if I put it to my ear?

Last night and tonight I completed the job I have not been looking forwards to due to my lack of skill. The lightweight 1.4 mm tubes to the thick inlet manifold flanges. I was really prepared for a big mess to happen. To start with I had to tack all 6 in place with the plenum chamber mounted atop and there was very little room. I wanted to tack each side so I knew the where in the right position and wouldn't pull. I could hardly get the torch in anywhere with the heads in the way. But I did it! And it wasn't too bad. in fact I'm actually bloody proud of it and for once since starting this alloy welding malarkey I don't feel the need to grind the welds down. This inlet manifold has taken a fair bit of argon (thank fuck I have found a source of very cheap argon..) and a fair few rods. I cant imagine the amount of gas engineering companies like boat builder must use!

Anyway- photos some weird shitty things- brown residue on the weld and I don't know how it happened?

Tonights work, halfway through, not perfect beads but sealed. I have finished them and any little lumps I smoothed over with the torch. It is so satisfying when it goes well. I noticed that I could get away with quite an angle on the torch when going up to and around corners - in places that I had no option to due to it being pretty tight in there. I also find it worked well to do a section at a time on one, then the other one and let them cool down in between. I mainly did this to avoid any warping but it also meant I had cool parts to lay a steading finger on. Then when I started the weld I gave it heaps on the thick flanges and moved the puddle up to the thin tube then started filling. seemed to work- I didn't blow any holes through at all which surprised me!

[Stu]

Looking pretty good!

Part of the problem you have with those runners is factory manfiold material is cast so you just about always get some contamination through the weld as the cast ali wont be the purest. Its best to almost just weld on the cast then slightly vere onto the extruded tube to drop the blob then come back onto the cast - that way your concentrating the heat into the thicker material (avoid blow out) but also gives it more cleaning time.

Gas flow wise you generally shouldn't hear the reg flow much (just the flow ball ticking inside the tube). I would try and lower the reg pressure as I said above - actually post a pic up of your reg please. I'll try and take a photo of the manifold I'm making (all new ali thou). Its fun making stuff like this.

[yoeddynz]

Oh weld envy! yeah one day I to wish to weld that neatly. I'll get a photo of the reg tomorrow. I was thinking of taking it back and complaining- upgrade to a better one. It doesn't have a tube with a ball. Its just two gauges side by side- one reading pressure of cylinder and one the output of reg. I think its a bit cheap? When it reads an indicated 4 L/min I can still easily hear the gas flowing from the nozzle- like easily. Trouble is if I try to drop it from 4 it just closes to no flow at all. Then I have to wind it back in till it 'pops' open again and try again. I'm sure its flowing too much and I would like to lesson the flow more until I get symptoms of low gas flow then I know where I'm at.

[Seedy Al]

cool man!