help out a lost cause (Alumium TIG)

[Seventynine]

right it's been many moons since i did a bit of aluminium, so i figured i better start from the beginning

problem is i don't remember it being this difficult?!

anyway, the problem i seem to have is the arc is wandering over a fair old area and causing nothing but a mess, as pictured here. i can sort of lay a bead but it's flat, scaly and, well, just a mess haha.

settings are -

6lpm (argon)
1.6mm tungsten (2% CE)
1.5mm 4043 filler
pedal set to 90 amps max
30-40% negative bias
100hz
cleaned the sheet with contact cleaner/stainless wire brush (it was brand new aluminium with plastic both sides)

tbh i tried most settings and didn't seem to get anything much better than the above!!

 

[HMB]

Contact cleaner? Doesn't that make nasty gas?

 

[biffa]

Is the machine set to ac? Are you sure it's a weldable alumnium?

 

[HMB]

After a few attempts myself

 

[gjn]

Contact cleaner? Doesn't that make nasty gas?

You're thinking of Brake Cleaner - that is nasty stuff when heated by welding.

 

[Stueeee]

Maybe the dirty looking beads and arc wandering could be reduced by getting the tungsten closer to the work. Might be worth trying a 1.6 Zirconiated Tungsten instead of the Ceriated one at that current too.

 

[Tigman]

what thickness is the sheet ?

 

[hotrodder]

Looks like a gas problem to me... what does the tungsten look like, clean and shiney or discoloured/manky? Zero etched zone (white bands alongside the weld) too but if there's a gas leak nothing will make a difference until that's sorted. Start with the 'spot weld test' http://www.mig-welding.co.uk/forum/threads/just-got-a-new-tig.27276/page-2#post-301703 ideally on stainless. Assuming you don't get a clean result then start with torch back cap O-ring and/or collet in backwards as two of the favorite suspects

Brake cleaner is surrounded by myths, it's NOT the toxic ticket to death that some make it out to be after reading about the idiot that poisened himself. Yes, he was using brake cleaner but the important bit is that it was chlorinated brake cleaner and IIRC he admitted to stricking an arc on a part that was still wet with a highly flammable solvent ANY chlorinated solvent can decompose producing phosgene when heated which is maybe one of the reasons why the stuff is pretty much outlawed in Europe these days and why brake cleaner in the UK is the non-chlorinated variety. Americans need to be vigilant as both flavours of brake cleaner exist over there

 

[Seventynine]

Contact cleaner? Doesn't that make nasty gas?

contact cleaner is essentially alcohol in a can

Is the machine set to ac? Are you sure it's a weldable alumnium?

how would i know if it's weldable? i bought 2kg of offcuts off ebay?

http://www.ebay.co.uk/itm/291008170...eName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

definitely on AC, it sounds like AC and the machine is set to AC (RTech 160)

Maybe the dirty looking beads and arc wandering could be reduced by getting the tungsten closer to the work. Might be worth trying a 1.6 Zirconiated Tungsten instead of the Ceriated one at that current too.

had it so it was that close it was difficult getting the filler in, got it stuck a couple of times but i really couldn't get it in any closer, i've been using it to weld mild steel perfectly

will try the zirconiated, although i think there's a bigger problem at play here personally

what thickness is the sheet ?

2mm

Looks like a gas problem to me... what does the tungsten look like, clean and shiney or discoloured/manky? Zero etched zone (white bands alongside the weld) too but if there's a gas leak nothing will make a difference until that's sorted. Start with the 'spot weld test' http://www.mig-welding.co.uk/forum/threads/just-got-a-new-tig.27276/page-2#post-301703 ideally on stainless. Assuming you don't get a clean result then start with torch back cap O-ring and/or collet in backwards as two of the favorite suspects

tungsten blacks up, balls up, erodes, all sorts depending on what settings i've tried, usually just goes a little black.

will have a look at the spot weld test, i can hear gas coming out of the torch if that's any use? and like i said i've been using it to weld steel for the last 2 years with little difficulty!

thanks for your help so far guys, i'm sure it's something simple

the gas bottle is an albee pure argon, any way to tell if it's contaminated?

 

[whm_fab]

I'd be definitely using more than 6lpm, I'd be up around 10/11 on that material

 

[doubleboost]

The material looks fine
Just a wipe with panel cleaner
Like already stated more argon
I use a R-Tech 200 it is very good on alloy

 

[hotrodder]

how would i know if it's weldable? i bought 2kg of offcuts off ebay?

http://www.ebay.co.uk/itm/291008170...eName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
2mm

The ally will be fine. No mention of flavour in the link but it'll probably be either 1050 or 5251. There are very few 'non weldable' flavours in general use and nearly all of those are bar stock not sheet. FWIW 'non weldable' doesn't mean they can't physically be welded anyway, just that doing so totally destroys their properties i.e. some super duper high strength flavour ends up softer and weaker than a common flavour does when you weld it and will also be prone to severe corrosion

tungsten blacks up, balls up, erodes, all sorts depending on what settings i've tried, usually just goes a little black.

will have a look at the spot weld test, i can hear gas coming out of the torch if that's any use? and like i said i've been using it to weld steel for the last 2 years with little difficulty!

thanks for your help so far guys, i'm sure it's something simple

the gas bottle is an albee pure argon, any way to tell if it's contaminated?

It's a gas problem then. The tungsten is white hot when welding and it's turning black and burning back as it oxidises. It should remain clean and shiney if gas shielding is OK and there's enough post flow. Aluminium and stainless are FAR less tolerant of gas shielding problems than mild steel. Turning up the gas WILL NOT fix it, ally is my bread and butter and i rarely run more than 6 lpm (often less) even welding castings/heavy stuff with the welder maxed. About the only time i get close to 10 or 11 lpm is with an extra large gas lens and a #12 (3/4" bore) ceramic when welding Ti. Wasting argon aside too much flow is just as bad as not enough... it can result in turbulent flow which draws air into the shielding zone

About the only way to find out if the argon is contaminated is to eliminate everything else or change the cylinder. It's very unlikely to be the gas itself (unless the argon is actually an argon/CO2 mix), more likely to be a dodgy back cap O-ring drawing air in and mixing it with the argon or a collet in backwards which does kinda the same thing and also blocks argon flow through the collet body. Obviously every other joint in the gas system is also a potential suspect

 

[chevy2]

At a first glance without reading any other comments i'd have said not enough ac balance on the cleaning side as theres virtually no etching zone on either side of the pool and lots of dark deposits (peppering) in the pool which often spells not enough ac cleaning,

Been picked up on here before that some manufacturers list there ac balance settings in reverse,
Do some test pieces with the ac balance adjusted fully at both ends of the dial or numbers if digital,
The side that gives the widest etching zone along the edge of the weld coupled with the tungsten wanting to get hotter and balling up much more than in the opposite direction is the cleaning side of your adjustment.

 

[Seventynine]

At a first glance without reading any other comments i'd have said not enough ac balance on the cleaning side as theres virtually no etching zone on either side of the pool and lots of dark deposits (peppering) in the pool which often spells not enough ac cleaning,

Been picked up on here before that some manufacturers list there ac balance settings in reverse,
Do some test pieces with the ac balance adjusted fully at both ends of the dial or numbers if digital,
The side that gives the widest etching zone along the edge of the weld coupled with the tungsten wanting to get hotter and balling up much more than in the opposite direction is the cleaning side of your adjustment.

the R-Tech balances the cleaning side to the lower half of the percentile (30% = most cleaning, 70% = most penetration)

http://www.r-techwelding.co.uk/Downloads/Tig_Welder_Owners_Manual_TIG201.pdf

i set it across the whole range with not much better luck

The ally will be fine. No mention of flavour in the link but it'll probably be either 1050 or 5251. There are very few 'non weldable' flavours in general use and nearly all of those are bar stock not sheet. FWIW 'non weldable' doesn't mean they can't physically be welded anyway, just that doing so totally destroys their properties i.e. some super duper high strength flavour ends up softer and weaker than a common flavour does when you weld it and will also be prone to severe corrosion


It's a gas problem then. The tungsten is white hot when welding and it's turning black and burning back as it oxidises. It should remain clean and shiney if gas shielding is OK and there's enough post flow. Aluminium and stainless are FAR less tolerant of gas shielding problems than mild steel. Turning up the gas WILL NOT fix it, ally is my bread and butter and i rarely run more than 6 lpm (often less) even welding castings/heavy stuff with the welder maxed. About the only time i get close to 10 or 11 lpm is with an extra large gas lens and a #12 (3/4" bore) ceramic when welding Ti. Wasting argon aside too much flow is just as bad as not enough... it can result in turbulent flow which draws air into the shielding zone

About the only way to find out if the argon is contaminated is to eliminate everything else or change the cylinder. It's very unlikely to be the gas itself (unless the argon is actually an argon/CO2 mix), more likely to be a dodgy back cap O-ring drawing air in and mixing it with the argon or a collet in backwards which does kinda the same thing and also blocks argon flow through the collet body. Obviously every other joint in the gas system is also a potential suspect

this sounds plausable, i'll give everything a service at the weekend to see if there's anything suspicious

turning the gas up to even 15lpm didn't yield anything better either!

 

[Jim Davey]

It's a gas problem, black, peppered up weld, black tungsten. It's either a leak, a collet inserted in the torch backwards, a draught or just not enough gas, or too big or too small a ceramic.
Just because it says six lpm at the hand wheel on the cylinder doesn't mean that's what you're actually getting. Look for obvious leak points, start at the bottle and work towards the torch. Then prep some plate, set balance to 50/50, put in a 3/8" ceramic and do a series of half a dozen test runs upping the gas flow by one lpm each time. I suspect you'll notice a marginal increase in weld quality with each pass until it then starts to tail off again. Write the settings for each pass down and go with the one that worked best.

 

[Seventynine]

thanks guys, will give the whole welder a once over this weekend

 

[Seventynine]

right so still a lost cause

went over the whole system earlier, put some PTFE on all connections, pressure tested everything and there is no leaks/areas for gas to get contaminated.

noted the points above and the tungsten is getting white hot and turning black which suggests gas, but could it be anything else?

(taken the shroud off here to see all of the tungsten, obviously welding like this would cause some shielding issues :lol: )

made a little video of what's happening to see if you can hear/see anything as it's really starting to bug me now, the frequency is set a little high as by this point it resulted in the least wandering

http://smg.photobucket.com/user/lat...0-494C-A23F-322B5B2645E7_zpseacgc3x0.mp4.html

and this was the result -

(for the record on a different set up i've managed at least to join some metal, so i'm 90% confident it's not down to me being completely useless!)

 

[doubleboost]

Have you tried it on DC welding stainless
This would verify the argon is pure
Ring the lads at R-Tech I am sure they would be only to happy to help

 

[wheresmejumper]

The first acdc tig I got welded like that.found a tiny leak inside the torch handle.
wasted a bottle of gas changing settings and fittings trying to find the problem

 

[hotrodder]

It's a long shot but what does the label on the gas cylinder actually say? The question make more sense after reading this... http://www.mig-welding.co.uk/forum/threads/help-with-first-time-ali-tig-please.32221/#post-352295