Rate my welds

[dutchman]

Hmmm, no respose yet...

Am I asking daft questions again or have I stept on too many toes by expressing some of my (questionable) political views???

 

[malcolm]

Hey, nice job there Woz!

I do have a question about the wandering arc though. I was surprised by the stability of the dc arc on my Lincoln machine, but I read Hitch's comment that arcs tend to wander a bit. Is that phenomenon worse with ac?

We missed the question there - became one of those threads you skin over, and it got skimmed over.

I find wandering arc worse on DC. On AC it's constantly stopping and starting and doesn't get a chance to start wandering (at least that's my theory).

I have it down as Argon shielding gas that causes the trouble. The MIG arc will wander if you run it through pure Argon.

 

[Wozzaaah]

have I stept on too many toes by expressing some of my (questionable) political views???

Not on your life! Everyone's entitled to express their opinions on here as long as nothing offensive is said, like Malcolm says, the question was simply missed.
My arc wander was more noticable when using AC, I think it's down to technique though, maybe tungsten to work distance a tad too long? Haven't really had time to play with the old beast much lately, will dust her off again soon .

 

[^neo^]

what do you mean by arc wander?

 

[dutchman]

I find wandering arc worse on DC. On AC it's constantly stopping and starting and doesn't get a chance to start wandering (at least that's my theory).

I have been theorizing about that too and my (also very questionable) explanation was that since the current changes direction on AC a new magnetic field has to be built (which is done at the speed of light, if I remember correctly). But during that fraction of a second the arc is not pulled into one specific direction and therefore has "time" to wander.
Another thing that I thought of was the shape of the tungsten; balled for AC, and thereby a larger wander surface as opposed to pointed for DC.

But this is just my amateuristic theory, not sure if it makes sense and there are other factors too off course, like the gas...

Not on your life! Everyone's entitled to express their opinions on here as long as nothing offensive is said.

Pfieuw! That's a relief.
Keep us up to date on your practice Woz

 

[Wozzaaah]

what do you mean by arc wander?

Exactly what Dutchman says, the arc seems to scatter all over the place before it settles to a normal shape. I was thinking that it can't help with the cold start you seem to always get with aluminium, If the arc was concentrated in the right place from the start it would get the weld pool going sooner. I reckon itcould be down to my lack of experience and maybe the way I grind the tungsten too .

 

[snowcat]

Ok pips, is it H/F wander your talking about, Or the actual welding current? I have a fealing your describing H/F....

With a properbly ground and sized tungsten on D/C your arc should be A1,

A/C the tungstens are generaly blunt so therefore the arc will not be as good, however weld pools are very hard to difine in Al so your less likely to notice a non perfect arc.

Cold start, is one of them things, shove the al in the Mrs oven, then preheat, you will be amazed at the improvement, Its all to do with the conductivity of the material Dont'ch know...


Does that make sense?? no proberbly not...Its too hot Tday

 

[runnach]

Hi Wozz, did you state matl thickness mate?? For example, if you are doing practice runs on 3mm al/al, you will get a wee bit o wander, then full arc control after a few nano secs. I would not pre-heat 3mm. Just allow heat to progress till you can move forward. One thought I am thinking here, perhaps the machine you are using is a little on the old side, HF gap may require adjusting a little.

Final point before I head back to the pool :-) Watch your arc length, maybe it is you that is wandering a little??

Cheers from sunny roasting hot Florida

 

[Woody.v8]

You can rate go off some folk cant yer

 

[Wozzaaah]

perhaps the machine you are using is a little on the old side, HF gap may require adjusting a little.

Final point before I head back to the pool :-) Watch your arc length, maybe it is you that is wandering a little??

Cheers from sunny roasting hot Florida

Hehe, you could say that Runnach, I reckon the old girl was built in the early 80's

I also reckon arc length has a lot to do with it, I don't think I'm anywhere near close enough for fear of grounding the tungsten.

Last but not least.................happy hols!


Snowy, I reckon it could be HF wander rather than actual arc wander but with my very limited tig experience I couldn't tell you for certain. DC is fine by the way, I've only noticed it on AC. Will definitely try some preheat and see what difference it makes.

Thanks again guys, cheers!

 

[snowcat]

I would not pre-heat 3mm. Just allow heat to progress till you can move forward.

Ohhh forgot people do weld stuff under 1/4"....

 

[^neo^]

Exactly what Dutchman says, the arc seems to scatter all over the place before it settles to a normal shape. I was thinking that it can't help with the cold start you seem to always get with aluminium, If the arc was concentrated in the right place from the start it would get the weld pool going sooner. I reckon itcould be down to my lack of experience and maybe the way I grind the tungsten too .

Ah, with you now.
It's because the HF will bounce about all over the place until the arc finally strikes, and being a 'balled' tungsten it has more surface area for the HF to bounce around (if that makes sense).
Can try a smaller ceramic which may help, but may just be down to the machine.

Only usually get it on my BOC when the amps are too low and it struggles to make the arc.

Another thing to try is to just stroke the tungsten across the ali before you put your foot on the pedal. Don't know if the tungsten gets a bit grotty, but it works.

 

[runnach]

Ohhh forgot people do weld stuff under 1/4"....

Usual story Snowie, thin stuff during winter, heavy stuff during the summer!! Hows the weather overthere? Melting here, 92f today Gotta go, pool time with wee drinkies hehe............

 

[Country Joe]

Listen people! I am the expert here!
Nah, only joking! - done about the same number of runs as you on ally, Woz - so hardly oozing with experience!
But if it makes you feel any better, it does the same wandery thing with me too, at the start of each weld.
But I don't have a pedal, so that'll have to be my excuse for now!
Fear not though, your welds look damned good for a first go - I wouldn't have had the nerve to post any of mine - put it that way!
I'll continue eavesdropping these sort of posts until I've got a set of runs worth posting, eh?

All the Best,
CJ

 

[snowcat]

Usual story Snowie, thin stuff during winter, heavy stuff during the summer!! Hows the weather overthere? Melting here, 92f today Gotta go, pool time with wee drinkies hehe............

not quite 92f but a pleasent 20C or so, no pool and no drinks tho, got a nice little card from posty saying theres a parcel to collect and pay the additional 6p postage, with a £1 handleing fee, jobsworthy cretin-is B****Ds, Iv got to go to town tommorow to swear at some other gits who havent done there job properly, So il be ready for a trip to the Soul zapping pit of despair that is our local post office...

 

[runnach]

not quite 92f but a pleasent 20C or so, no pool and no drinks tho, got a nice little card from posty saying theres a parcel to collect and pay the additional 6p postage, with a £1 handleing fee, jobsworthy cretin-is B****Ds, Iv got to go to town tommorow to swear at some other gits who havent done there job properly, So il be ready for a trip to the Soul zapping pit of despair that is our local post office...

Hmmmmmmmmm, 6p short plus £1 handling fee, sounds pish, who the heck delivers your area, private company I assume? Another belter with the heat again today!! 8.30 T-off, 4 hours later to the 18th, shirt was frikking soaking, now I understand why they use them wee golf carts, nearly rolled mine trying to do wheelies hehe..........nice bit o eye candy kept us in cool drinkies, thank da lord!!

Anyways, one mother of a storm overhead, just finished watching the footie, good game............siesta time............

Cheers............

 

[snowcat]

Payed my toll of £1.06 to the cretins, So expect interpass and a preheat tempretures to be quoted with authority, from now on, cheers T......, Florida is a Tad on the well emmm humid side for me, travel'd through there before and had all the gear in me rucksack go mouldy, nice....

Thought this was a WORK trip, hmmmmm

 

[runnach]

Payed my toll of £1.06 to the cretins, So expect interpass and a preheat tempretures to be quoted with authority, from now on, cheers T......, Florida is a Tad on the well emmm humid side for me, travel'd through there before and had all the gear in me rucksack go mouldy, nice....

Thought this was a WORK trip, hmmmmm

Ah, arrived now eh, good to see the wheel has a home where it will be put to proper use. I'll be awaiting future authoritive qoutes ma man

Work complete now Snowie, fun all the way till Monday, then head back home Then again, I may just pack my lad off, I have 6 weeks hols left

 

[Wozzaaah]

Had another play with the old beast this afternoon (fnarr fnarr ) with mixed results. A few half decent runs and a few where I just couldn't get the weld pool started and ended up with the filler just balling up on the surface. Also touched the tungsten with the filler a few times again which is very frustrating when you're part way along an acceptable run .
Was still getting that HF scattering at the start of the run quite a lot so I checked the spark gaps, they were ever so slightly wide so i adjusted them as per the spec. This seemed to make a noticeable difference, the arc seemed a bit more focussed and the weldpool was easier to get going.
I desperately need a new torch though, I burnt my hand a little where the cable gets hot on the weak part and that was with gloves on too! I'm sure it's sapping a lot of current away from the tungsten which is why I'm having to stamp on the wah-wah pedal a bit more than I should be. I'll have another go tomorrow and upload some more pics for your amusement .

 

[runnach]

Wozzaaah, regarding HF contactors, if they are pitted, this will have a slight detrimental effect on start up. If you have to face them off, use a proper machine tool grinder to make a sound smooth surface. A grinder or file is of no use mate.

One other point, are you holding torch in pistol grip fashion, or similar to holding a pen while writing? Also helps if you have the harness supported a little to take the strain of you're wrist. Oh, water or air cooled torch?

Cheers............