Struggling with Ali welding

[Van_Denton]

Hi guys, Im teaching my self to TIG weld. I seem to be getting the hang of welding steel and stainless but im totally struggling with aliminuim.

my first problem is that as I lay a bead it heats up and flattens out over time, so it starts off nice but then as i travel along the weld gets flat, ive tried speeding up and backing off the pedal but it always seem to do it.

secondly its penetration, should i see evidence of the pool on the back of the sheet? its 2.5mm.

thirdly the weld seems to be pitted, ive tried upping the flow rate to like 15 and 20 but it doesnt really make a difference.

I guess thats it for now, any pointers would be great.

these are various examples over a few days.

Cheers,

Paul

 

[Paulbarrett]

Hya paul

That sheet could do with a clean down with a stainless wire brush to remove some oxide.

Im no expert but im sure you will be asked what tungsten size you are. Using and gas flow rate.

Those welds look really good though!

 

[hotrodder]

1. That's just the nature of ally but it's waaaaaaay more noticable on small offcuts than larger parts where changes to amperage/travel speed as the job heats up are more subtle. Cut yourself a bunch of larger strips and then tack them together into two larger coupons each with several joints. Swap between them as they get heat soaked

2. Yes but i wouldn't worry about that too much for now. There's a fairly fine line to walk between making a mess and full pen welds without excess penetration and other flaws. Pic is an extreme close up but shows the front. back and cross section of a weld on some 1.5 or 2mm ally



Can just make out the 'oxide line' on the root side which is normal but can hide various flaws

3. The pitting looks like grainyness which is fairly common with 4043 filler wire when the weld/part has gotten too hot. Some brands of wire are worse than others and various other things influence things too. Again i wouldn't worry about it too much for now but i would avoid cranking up the gas flow up lots. It rarely fixes problems, often makes them worse and about the only thing it'll always do is waste argon

 

[Van_Denton]

Hey Paul

Thanks for your reply Yeah I need to get myself a stainless brush. My garage is in rag order at the moment as im building benches, painting it and re doing the electrics ! So i need to sort all that out first before I can get properly comfortable.
The door is open if you wanna pop round for a cuppa when Iv got it a bit more sorted.

Im using 1.6mm white tungsten with 1.6mm 4043 filler and about 10-15 lpm on 2.5mm ali.

Thanks for your reply Hotrodder, your example looks amazing, my weld definitely doesn't come through the back like that its just sitting on top. At the weekend I will cut myself some larger pieces and do as you suggested.

I find it hard to back off on the pedal as when I do it splutters and spits, I think the pedal is not so great as it seems abit like all or nothing.

Here is tonight's effort, Im trying to practise every night but its hard to identify whats wrong on your own.

At the moment I find it hard to move my hand, I seem to be resting it and just moving my wrist, this leads to me being only able to do short runs that I have to start again. That and not being able to feed the filler, I cant manage to squeeze it through my fingers accurately and hit the puddle. I guess its just practise.

Thanks for looking guys

 

[Paul.]

I would go up to a 2.4 tungsten, and a 2.4 filler, gas is a little high, 6 to 8 lpm is plenty on ally, any more is a waste, material is not that dirty by the look of it, a stainless wire brush should be part of your tool kit, but a rub with some scotchbrite is just as good and wont damage the material as much, I hate to see brush scratches on jobs, don't fall into the trap of lathering everything in acetone either, at this stage it wont help,
What you have achieved is not too bad for a beginner, some one to one tuition to spot where you are struggling can make a big difference at the stage you are at,

 

[Paulbarrett]

See i told you you paul this forum is ace! almost instant help and guidance. The gugs on here are so helpful and passionate abotu what they do for fun and mostly a living!


Will definately have to pop over some time mate check out the den.

 

[Van_Denton]

Thanks guys, yeah Paul it seems a great forum. Man the Pauls are all up in this thread!
I will try a bigger tungsten and rod, cheers. I would love some 1 on 1 tuition but not sure where to get it, will have a look for some welding schools to see if I can get a lesson or 2.

Thanks again for the replies.

cheers,

Paul

 

[Paul.]

I'm happy to give you some time, but it probably wont be for about 3 weeks if you can wait that long, I have a small but well equipped workshop in Kingsthorpe where I earn my living doing light fabrications in mainly stainless and ally, plenty of offcuts laying about for practice too. you could bring your own welder and I'll work through it with you, PM me if you want to or if you need any practice material.

 

[TechnicAl]

Thats a fantastic offer from Paul. His work is second to none. You should grab the chance. You would pay big bucks for a masterclass like that.

 

[Richard.]

Defo not a bad attempt at all.
http://www.mig-welding.co.uk/forum/threads/aluminium-tig-guide-getting-started.64695/
Some info on setting up that I slapped together to help people starting out with Alu.
Take Pauls offer up. It will be a priceless lesson and you'll walk away feeling much more confident.

 

[Van_Denton]

Hey thanks Paul thats a very generous offer and Id love to take you up on it, I actually live in Kingsthorpe too. I will PM you.

Hi Richard, Thanks yes ive read your great guide, probably about 5 times as I kept checking I was doing it right.

Hey TechnicAl, yes I will cheers.

 

[gordon stephenson]

Really excellent offer from Paul, Looking forward to your feedback on the experience, Well done Paul.You are a gent.

 

[Richard.]

I've done quite a bit of experimenting with the grainy appearance often found in Si alloyed fillers and have got to a point where I can purposely achieve it. While I haven't tried it with cheaper or inferior filler as I refuse to buy such things the link I have found most effective is travel speed. With a current set low and a slow travel rate this in turn increases your heat input higher than if you had the current cranked up and traveled at a rate. The clumpy grainy run is a lot more elaborate welding slow. Gas levels are not the cause and cranking it up is gonna make things in other areas worse.
I think your doing alright and a little 1-1 is all that's needed.

 

[norlander]

it splutters and spits,

My garage is in rag order at the moment as im building benches, painting it

I have just had to gun out some ali welds today, hideous mess, black smutty porosity, not puddling up . Cleaned the work up again with carbide burr, then acetone and got a result of sorts.

Never had the problem before. Wiped over filler rods with acetone, new tungsten, still a mess.

Then I noticed some bright steel I had just bought had flash rusted. I had a bath of Hydrochloric acid sitting just outside the shop with a vented cover over it, stripping some spanners for a project, every so often I was getting a whiff of gas; so I moved it away.

Quite possibly, its contaminated the ali-I keep my filler rods protected, I had an ultrasonic bath about 5' away from them and found that was not good for them.

So maybe if you are painting etc in the TIG area, that might cause some issues.

Sounds daft, but I think thats whats happend to the ali stock I have.

 

[Van_Denton]

Hi Norlander, thanks for your advice, I have just been painting the walls with emulsion so I dont think its an issue but I will keep my filler rods protected even so they just stay clean.

Not had that much time lately to practise, I still need to cut off some bigger pieces to practise on but cutting the Ali is a pain for me. I have been using scotchbright on the pieces and have also tried welding some tube just to change things up abit.

I find it quite difficult to make a tac with Ali.

Here I cut a few pieces.

This is my setup. They get hot pretty quick and I did blow a few holes in some.

I find it hard to make the tac, the best result was starting the puddle on one side of the join and trying to drive it over to the other side with a spot of filler.

Here you can see my inconsistency.

Every time I weld I do feel like I've learnt something so that is cool just need to pick up some more gas and practise. The little hobbyweld tanks I use dont seem to last long, I need to do that BOC VZI deal I read about, anyone know if that still exists?

Also went to a car boot the other day and picked these up for a pound, I know they are not going to make me a better welder but I have a 4 hour commute everyday so its something to read on the train!

Thanks again,

Paul

 

[Richard.]

Why are you cutting them up so small. That really is going to make life harder when learning. Those tiny tube sections are gonna heat up quick as a flash making pool control very difficult . Leave them in 1 long length and practice your runs along the length and around the circumference. No need to cut it up so small. Draw your imaginary joint to follow but give yourself a chance with pool control and keep your practice parts as big as you can.

 

[Van_Denton]

Well today I was very fortunate and got to pop round Pauls workshop for a little Tig tutorial, Id like to say a public massive thanks to Paul and this forum. He took time out of his day to help a total stranger and I cant thank him enough. I still have ALOT to learn but feel ive been given a push in the right direction. Its just going to be practise, practise and more practise from now on.

Here is a corner joint I managed, something I couldnt do before with proper penetration. I know it still looks bad and i stopped in the middle twice but for me its a vast improvement.

thanks guys

 

[ukracer]

Well today I was very fortunate and got to pop round Pauls workshop for a little Tig tutorial, Id like to say a public massive thanks to Paul and this forum. He took time out of his day to help a total stranger and I cant thank him enough. I still have ALOT to learn but feel ive been given a push in the right direction. Its just going to be practise, practise and more practise from now on.

Here is a corner joint I managed, something I couldnt do before with proper penetration. I know it still looks bad and i stopped in the middle twice but for me its a vast improvement.

thanks guys

I picked up on this thread as we have both been at it today. I will say immediately I am no better welder than I was before I met with Richard today BUT I do feel I have more knowledge on what I need to practise.

Even the comments early in this thread I can now visualise and know what to do to counteract it.

One thing I learnt today was clean material is relative. Knowing what to do is more important.
Second my welder is as good as I thought it was in the hands of an expert.
Third the size of tungsten is important or Richard would not have changed it so I need to learn about thickness.
Fourthly the tip of the tungsten is not as important as you think....I.e if it's blowing the end of its your settings , its not your grinder.
Five You need more power than you think to start with and you need to back of less than you think.

six all of this is running a bead on 3mm ish Small pieces of Ali. It gets her soaked quicker than you can imagine.

seven I am not a welding instructor or even a welder....but think I can now understand what is being said.. I hope.

 

[Richard.]

The tip of the tungsten is important ukR. You need to set the balance right to ensure it remains stable. (30-35% on your machine mate).
You are a better welder than you were before because your last run was night and day better than your first.

 

[Richard.]

UkR. If it should ever be appealing to do another 2 hours drive we can sort out a proper 4 hour session. 1 hour today was difficult to try and cover much and I think you've got some good tools to get it mastered.