tig welding thin aluminium

[rebekah_harper]

hiya every one.

I have a question.

I am a beginner and I need to weld aluminium for the project that I am working on.

I bought a WSE200 tig welder which is cheap but works reasonably well.
the down side about it is the fact that there are no gradients on the amp selector which is a pain.

how ever I am able to produce a good bead ( I think this is the term used) so having procticed this I have moved onto the project orientated practice which is butt/fillet welding. I work with thin aluminium (down to 1mm).
2mm is fine although the weld is bigger than I'd like but the two pieces weld together but when I try 1mm I can't seem to get there.

I can't get a puddle to form in the joint. they are always 2 to 3 mm away. I don't understand why I can't get the arc to move closer. when I try it jumps on to the other piece again about the same distance from the join.

when I get a puddle to form on one piece I can't seem to get it to move closer to joint. when I get puddles on both pieces I can't get them to join up.
most of the time whilst I try and achieve this I blow a hole through the piece.

I use the peddle and try to keep as low as possible. I use pure argon at about a flow of 15.
I use 1mm pure tungsten electrodes

please help with adviceor if any one is near Waddington. I would be happy to pack it all up and come to who ever to first see if the equipment is good and hopefully to teach me. arrangements can be made if required.

many thanks

bex

 

[pedrobedro]

On material that thin you don't want a gap between the two pieces. Tack them together frequently to stop them moving apart. Turn the amps down and work your way up till it forms a puddle and keep the surface of the aluminium clean (very important, the oxide layer is the bit that causes the problem)

 

[gordon stephenson]

I think I remember seeing on 'Welding tips and tricks" for thin alloy, set current to about twice normal for the thickness have a good clean fit up and just zap the pedal for a split second to tack the joint, Check out google for tig micro tack there maybe something there,Then reset the current once tacked for doing the seam.
Found this on youtube about some Kemppi sets.http://www.youtube.com/watch?v=YvYSq_HbiSU

 

[hotrodder]

As Gordon the way forward for tacking is quick and hot however...

To stand a chance on 1mm ally (especially fillets) you really need to be pretty damn good with thicker stuff first. By pretty damn good i mean comfortable enough to produce the goods while talking to someone, singing along to the radio or even dancing

Obviously you're gonna carry on anyway sooo the gas flow of 15... 15 what? if it's litres per minute then turn it down to 5 or 6. Rarely need more than 7lpm with TIG
Throw the pure tungsten in the bin, zirconiated (white tip) is soooo much better as is pretty much any flavour except for thoriated (red) on ally. Pure tungsten has a higher electron function (doesn't strike as well) and tends to melt a lot producing a large balled tip. A balled tip is normal on ally but a massive one can result in arc wander. Personally i'd be using a 1.6 tungsten and sharpen it some- the tip will melt and round off but it'll should result in a smaller ball and a more stable arc

You need a short arc length, the arc will still wander a little when first striking up and tend to favour on piece. The answer is short arc length and (for tacking) hot and quick

If no one local to you offers to help then post some pics up as a pic is worth 1000 words an all that. If you go this route then letting us know what the balance settings are will be helpful (see this thread) as despite not being a 'make or break' setting it can make life harder or easier along with other functions like AC frequency etc

 

[FranV8]

Rebekah, couple of tips I've found, but much less experienced than Hotrodder, Pedro and Gordon:

- Have you got a pedal? Probably more of a necessity on aluminium than steel I've found
- Clean clean clean. I've found sometimes,es my weld puddle sits there in two if the ,metals not clean.
- tungsten to work gap - needs to be really, really close, then you'll find the arc going where you want it to. Again, ally seems much more sensitive to this than steel.

Good luck with your progress!

 

[Drains]

I have to admit, when it comes to welding 1mm aluminium I like to do it with a pop riveter.

Sorry, not much help, but sometimes you have to think sideways...

 

[snowcat]

Or glue it, works for Airbus, again not a great help.

 

[rebekah_harper]

brilliant guys, great response.

I will get onto addressing these points.

tungsten is to be white? fair enough. I will just use up the ones I have and change to white lol. the flow is in lpm and oops there it goes. so I will reduce that. the gap between tungsten and work piece is a big one, I though 4 mm so I shall be practicing that one then.

the one thing I find annoying is the lack of gradients on the amp dials. not on the machine not on the peddal. so It's a little guess work but I will see where I go with it.

thanks again and I will let you all know how it went unless I burn my shed down lol

cheers

bex

 

[Shox Dr]

4mm for 1mm work piece is massive, it needs to be less than 1.5mm

 

[Ragnarok]

doesn't have to be white (zirconiated) could be grey (ceriated) or one of the colours of lanthanated 1.5% or 2% are supposedly best, 1% is available too, the lanthanated would probably be ideal as they'll keep a sharper point in AC than the white zirconiated ones, also some of the multi type ones are suitable

 

[derekm]

I have the same set as u, am a begginner and have welded ally tanks down to 0.5mm good enough to hold water.

I used white or gold tungstens.
I used a smaller cup 4 or 5 on the 1.6 and 1 mm tungsten and lowered the flow rate
I started with a larger tungsten until I got the knack .. try a 1.6mm Tungsten first.
I started with outside butted corner welds first.
Every thing clean and sharp
Work piece at eyelevel.
I got the technique with 1.6mm ally with a 2.4 tungsten then moved smaller and refined it.
I put in the hours practicing. it took many weeks practicing 2 more nights a week a couple of hours each night.

Think of it as something like golf... but much more useful

 

[FranV8]

Great analogy! I'll log that one.

 

[rebekah_harper]

thank you

cheers guys for the advice.

I have applied most of it and am finding that the 1mm tungsten isn't burning up like it normally does.
I managed to weld a U shape out of 3mm legs and 2mm base. the thing I got caught out on was the ends. some how I melted some of it away which wasn't a great issue but still noticable. but I realised that if I keep it more on the larger surface and away for the side of the leg I manage to get a reasonable finish.

I will change the cup to a smaller one and reduce the flow even more.

I still manage to blast holes in the 1mm I just seem to get stuck on just starting the puddle in the first place. I do eventually get it but it's not pretty and there is still a series of holes in it.

I have found that instead of dipping the filler I just slide in and out of the puddle as and when required works really well for me.

I am using grean tips at the moment but I will get white when I finish with these. I am going to need gas soon too but I will cover that later with BOC.

I would like to ask if any one has used a pensil torch. This seems to a good idea for me considering some of the potential tight spaces I will be welding.

any how I will let you know how things go and try and put some pictures up of the success and failures.

cheers

becky

 

[hotrodder]

Pencil torches can be invaluable very occasionally but most of the time they are PITA as their design means your hand is placed directly over the hot weld. A flex neck torch is FAR more useful... the head can be bent around to different angles. A search of the TIG forum will get you some pics, TIG Paul has posted pics of them bent about and maybe even broken examples that show how they work

I'm not having a pop but is sounds like you going about things in completely the wrong way. Read the TIG tutorial, yeah i know there's not much about ally in it at the moment but that's beside the point. It advises beginning with simple stuff in the 2 - 3 mm range for a reason. If you don't go through the boring, repetitive stuff to learn the muscle memory needed and develop the correct techniques you will struggle, develop bad habits and maybe never 'get it'.

Again, control of arc length is VERY important. Especially with thin stuff and especially when welding in tight spots/corners.

Not specific to what you're trying to do but an example of 'quick and hot' with regards to tacking...



It's 1.5mm wall 1.5" tube. Ignoring the tape for the minute if you build the heat slowly to get a weld pool the edges WILL tend to 'melt back' rather than melt together. Using sticky tape as 'clamps' the tape would melt/burn and create a mess anyway. You'd usually weld 1.5mm ally at around 65A (maybe less for small pieces as they heat up quickly). Those tacks are autogenous (no filler wire used) and were made by turning the welder up to 90+ amps, holding the tungsten VERY close and giving it a quick blast- literally a tap of the button or a quick stomp on the pedal

Welding ally without filler wire ain't a good idea as it tends to crack. A similar technique can be done with wire but you need to be quick i.e. react without thinking and accurate (or you get a giant hole with thin stuff) which will never happen if you don't nail the technique on thicker/easier stuff first