What's Going On? TIG 4043

[Brad93]

hi all picked up some new rods today to continue practicing my TIG welding aluminium. was using 5356 but joy on welding tips and trick said 4043 is fine if you're not anodising the part. So bought 2kg of 4043 from BOC today but they're welding funny.
See pictures.

The nice smooth bead (albeit with a bit of dirt in it from dirty tungsten and old rods) is using my old 5356 2.4mm rods the bumpy/spotty but clean bead next to it us using the new 4043.

Any ideas

2.4mm tungsten zirconiated
Scrap but new 3mm aluminium still had clear blue sticky plastic on it.
160 amps but on the pedal
Rtech 201
Balance around 10 o clock

 

[wheresmejumper]

Did you try wiping the rods with acetone?
a supplier i used get rods off would put some brown sellotape around them 'to keep them from moving around in the tube'.

 

[hotrodder]

http://www.mig-welding.co.uk/forum/threads/surface-of-ally-weld.24510/#post-267950 I'm gonna go with arc length too long based on the LOF (lack of fusion) visible at the start and end of each of those welds including the 5356... the welds with 4043 look cold (profile/toe of the bead) and overheated at the same time

Done on steel but applies to ally as well http://www.mig-welding.co.uk/forum/threads/arc-length.7862/

 

[Brad93]

Haven't got any acetone kicking around to try that sadly.

Will try keeping an even shorter arc length.

 

[Richard.]

This is Quite common of 4043 to give the speckled effect and I've seen the problem arise Afew times on different threads. I believe it is a combination of silicon content in the filler starts to clump up and show the speckles when they are run too hot but as Hotrodder rightly says your runs look cold. The strange thing is although I've seen this similar problem come up many times it always seems to be a different solution that solves it. Arc length, filler cleanliness, ac balance, even a softer sin wave rather than the conventional inverter square wave tends to help this in some cases. All I can suggest is look through as many threads as you can about it and follow the advice from members on each case until it resolves the issue. I found I was getting contamination issues with my rods absorbing moisture from been open in the cold shop. I now keep them in the airing cuboard and bingo never an issue again. I went to hell and back before I figured it out mind.

 

[Rrunnach]

Witnessed a few fab jobs scrapped coz the fab/welder failed to read the drawing properly, where component was to be anodised!

 

[Richard.]

http://www.mig-welding.co.uk/forum/threads/surface-of-ally-weld.24510/#post-267950 I'm gonna go with arc length too long based on the LOF (lack of fusion) visible at the start and end of each of those welds including the 5356... the welds with 4043 look cold (profile/toe of the bead) and overheated at the same time

Done on steel but applies to ally as well http://www.mig-welding.co.uk/forum/threads/arc-length.7862/

Hotrodder does the Si content of those rods cause this grainy effect because of the higher melting point of the silicon over the aluminium? I've never really understood why it clumps like that in many cases.

 

[Rrunnach]

I can't recall having any issues, or problems when using 43's & 56's filler wire. Also this madness with cleaning al/al, if every weld required a clean when sheet or plate came off a pallet, job would never be done in time.

 

[whm_fab]

does the filler look oxidized? if the filler has been sitting around a long time, they will oxidise a polish of the filler with some scotchbrite (alu only) and then a wipe with acetone - makes a huge difference, the filler should be nearly mirror finish

 

[Richard.]

I can't recall having any issues, or problems when using 43's & 56's filler wire. Also this madness with cleaning al/al, if every weld required a clean when sheet or plate came off a pallet, job would never be done in time.

The oxide layer is pretty much fine to leave in tact as the ep% will be happy enough removing that but aluminium is not happy with been contaminated. So general dirt grease water etc should be cleaned before welding. I agree people do get OTT with Ali prep in thinking they must completely remove the oxide layer. Back purge has a good vid showing its best left alone.

 

[Rrunnach]

I manu'd a fleet of first generation ROV's for the then SubSea Offshore, now SuBSea7. Only time marine grade al/al plate got a scrub, if a tungsten dip at a difficult to get at area. All welds 100% NDT, Rover rated at, can't remember, something like 5000MSW, I never had one dipper. I think some folks get a tad paranoid when nailing al/al, when it is not really necessary.

 

[Richard.]

That's what I Just said. Unless it's generally dirty or grease, oil etc Then it's best to leave the oxide layer to the ac wave.

 

[Rrunnach]

What I said too "sheet or plate came off a pallet".

 

[Brad93]

Tried an even tighter arc length but if I didn't touch down it was still grainy. I'm using 6lpm of argon. 5356 still running clean.

If I turn the amps up I get so much horrible penetration/bubbling on the back of the sheet.

Maybe I should try and get a video with the gopro.

 

[Brad93]

If anyone is in the Essex area and would like to earn some beer money giving me a few pointers send a PM please bored of wasting ally, tungsten and gas now.

A run through of settings:
R-tech 201
Pure argon 6lpm
Size 7 cup
Zirconiated 2.4mm tungsten
2.4mm filler rods
165 amps on the pedal
Frequency around 100hz
Balance at 11 o clock

 

[hotrodder]

Balance set at 11 o'clock means nothing to me as i don't own an Rtech. IIRC turning the balance up on them increases the EP (amount of 'cleaning') but don't know what 11o'clock corresponds to on a knob that goes from 1 - 10 or what range of balance % that represents. From the etched zone and lack of black specs in the welds it looks to be in the ball park, certainly within the usable range. Everything else is OK, you might find turning the AC frequency down to 50 - 70Hz helps regarding the grainyness (come back to that later) and amps are on the high side for 3mm but obviously with a foot pedal you only have 165A with pedal floored... what sort of speed are you welding at?
FWIW tacking aside i typically dial in just over what i need personally as it results in better resolution/finer amperage control for a given foot movement

Hotrodder does the Si content of those rods cause this grainy effect because of the higher melting point of the silicon over the aluminium? I've never really understood why it clumps like that in many cases.

I'm not exactly sure what causes it... the two most common explanations i've heard are 'bad filler wire' which i call BS on* and it's the result of too slow/too hot i.e. the weldpool takes too long to freeze. I don't really buy that as the sole cause either, at least in terms of too hot/too slow as i've never had grainy welds with 4043 using an old transformer machine but i can make it happen with my inverter using exactly the same batch of wire quite easily.
Inverter/advanced squarewave seems to make a difference in that using my v205t i can weld faster and produce a smaller fillet on thin sheet than i can using a big ol' transformer yet while i find it difficult to produce a grainy weld with the transformer there's a fine line to walk to avoid that with my inverter. Especially at higher AC frequencies despite the fact that lower frequencies put more heat into the part

Adding Si lowers the melting temp of aluminium until the eutectic composition is reached and then it starts climbing again. The internet says the solidus temp of 4043 is 573.9°C and the liquidus temp is 632°C. 1050/commercially pure = 646 and 657°C, 4047 = 577 and 582°C. Too high of a heat input + the wide melting temp range must have some effect on solidification, the 'harsher' squarewave arc of inverters (especially at higher frequencies) seems to as well, maybe to do with something like weldpool agitation

* I don't doubt bad batches or even brands of wire exist but personally i've never experienced any that i couldn't get clean welds with

 

[Richard.]

If anyone is in the Essex area and would like to earn some beer money giving me a few pointers send a PM please bored of wasting ally, tungsten and gas now.

A run through of settings:
R-tech 201
Pure argon 6lpm
Size 7 cup
Zirconiated 2.4mm tungsten
2.4mm filler rods
165 amps on the pedal
Frequency around 100hz
Balance at 11 o clock

Do u really need tuition. I don't think you do. Your happy with the results of the 5% mag so it's just the change of filler causing the problem. If you would like you could send me some of your rods and I will see if I can get them to go and give you some settings if that's any help. 11 o'clock balance on that machine looks to be a balanced wave from the pic. Set it fully anticlockwise (30%) and tune from there.

 

[Richard.]

Balance set at 11 o'clock means nothing to me as i don't own an Rtech. IIRC turning the balance up on them increases the EP (amount of 'cleaning') but don't know what 11o'clock corresponds to on a knob that goes from 1 - 10 or what range of balance % that represents. From the etched zone and lack of black specs in the welds it looks to be in the ball park, certainly within the usable range. Everything else is OK, you might find turning the AC frequency down to 50 - 70Hz helps regarding the grainyness (come back to that later) and amps are on the high side for 3mm but obviously with a foot pedal you only have 165A with pedal floored... what sort of speed are you welding at?
FWIW tacking aside i typically dial in just over what i need personally as it results in better resolution/finer amperage control for a given foot movement


I'm not exactly sure what causes it... the two most common explanations i've heard are 'bad filler wire' which i call BS on* and it's the result of too slow/too hot i.e. the weldpool takes too long to freeze. I don't really buy that as the sole cause either, at least in terms of too hot/too slow as i've never had grainy welds with 4043 using an old transformer machine but i can make it happen with my inverter using exactly the same batch of wire quite easily.
Inverter/advanced squarewave seems to make a difference in that using my v205t i can weld faster and produce a smaller fillet on thin sheet than i can using a big ol' transformer yet while i find it difficult to produce a grainy weld with the transformer there's a fine line to walk to avoid that with my inverter. Especially at higher AC frequencies despite the fact that lower frequencies put more heat into the part

Adding Si lowers the melting temp of aluminium until the eutectic composition is reached and then it starts climbing again. The internet says the solidus temp of 4043 is 573.9°C and the liquidus temp is 632°C. 1050/commercially pure = 646 and 657°C, 4047 = 577 and 582°C. Too high of a heat input + the wide melting temp range must have some effect on solidification, the 'harsher' squarewave arc of inverters (especially at higher frequencies) seems to as well, maybe to do with something like weldpool agitation

* I don't doubt bad batches or even brands of wire exist but personally i've never experienced any that i couldn't get clean welds with

Can you change the AC pattern on your v205?

 

[Brad93]

Hi Richard yes PM me your address and I'll send a few rods over. I will get hold of some acetone and probably just get some more 5356 and some 1050.
I agree with the penetration the welds I done last night were much better on that front than ones I had done before.

Yeah on the r tech max cleaning is clockwise max penetration is anticlockwise the knob goes from say 9 o clock to 3 o clock.
On clean new ally I get a nice cleaning action around 10-11 o clock couldn't tell you what percentage EP that is because the r tech manual talks in riddles.

 

[Richard.]

I believe fully anticlockwise (30%) is 70% DCEN which is around the figure your looking for but you'll need an RTech owner to confirm this. Most of my AC Tig is done at 65-70% DCEN unless working with cast then I go to around 55% DCEN. Does your machine have the facility to change the AC half wave. Sin, tri, square. Mine does but if your locked into square wave as a lot of inverters are then I'll just keep it in square wave so you are able to replicate the settings I find. Pm on it's way.