Got some more tungstens today and had another go. I guess these look slightly better (slight being the operative word). Read up a little, a bigger cup, paid more attention to arc length. But the tungstens still turn out TERRIBLE. At the moment, I have to regrind the tungstens after each bead...
- Thread starter Llundberg
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Shox Dr
Chief Engineer to Carlos Fandango
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Looking better, still way to much heat. And you will NEVER get a decent looking weld unless you clean the mill scale off first.
Preparation, Preparation, Preparation, Preparation, Preparation, Preparation, Preparation
oh and Preparation
Preparation, Preparation, Preparation, Preparation, Preparation, Preparation, Preparation
oh and Preparation
I'm no expert, but I used a flap wheel to clean the metal. Before that I was getting similar stuff on my cup. I was going to use acetone as well, but what little I did have had evaporated away from the last time I used it. I really must remember to put the top back on 
What gas flow are you using? Isn't the colouration at the side of the weld a lack of gas shield?
What gas flow are you using? Isn't the colouration at the side of the weld a lack of gas shield?
I'm no expert, but I used a flap wheel to clean the metal. Before that I was getting similar stuff on my cup. I was going to use acetone as well, but what little I did have had evaporated away from the last time I used it. I really must remember to put the top back on
What gas flow are you using? Isn't the colouration at the side of the weld a lack of gas shield?
Will try a flap disk, I have them but thought that was perhaps a little harsh.
Have no idea but there is definitely gas flowing...
That creates the question : How do you know the mill scale is removed. using a flap disk it certainly seems clean.
Drains
Yeah, nah.
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You know because mill scale doesn't look like bare metal.
Some steel sheet is supplied cold rolled - no scale, just metal with perhaps a very thin sheen of oil. Other sheet is hot rolled and scaled. The scaling is a version of black. Flap discs certainly remove it, but take longer to cut through the stuff, and there is definitely some rubbing as well as cutting through, unlike with a grinding disc which just gets in there.
There is also a qualitative difference in the scale on different sections from different mills, so it's one to be judged on the day.
Lundberg, if you're not touching down but your tungstens are dissolving, check you are using the correct polarity (electrode negative), and if you have that right, check all your gas connections for leaks (air can be drawn in), shut the doors and windows so you can guarantee no draughts, and if none of that works take the gas back to the dealer and ask for another bottle. Tell them you don't believe it's pure argon.
Some steel sheet is supplied cold rolled - no scale, just metal with perhaps a very thin sheen of oil. Other sheet is hot rolled and scaled. The scaling is a version of black. Flap discs certainly remove it, but take longer to cut through the stuff, and there is definitely some rubbing as well as cutting through, unlike with a grinding disc which just gets in there.
There is also a qualitative difference in the scale on different sections from different mills, so it's one to be judged on the day.
Lundberg, if you're not touching down but your tungstens are dissolving, check you are using the correct polarity (electrode negative), and if you have that right, check all your gas connections for leaks (air can be drawn in), shut the doors and windows so you can guarantee no draughts, and if none of that works take the gas back to the dealer and ask for another bottle. Tell them you don't believe it's pure argon.
I'm thinking your pure argon is actually something else or at least that you have a shielding gas related problem like a leak. Coated steel could account for some of the issues but the tungsten pics are showing discolouration (oxide heat tints) miles away from the tip i.e. contamination from coated material or dunking the tungsten will only effect the tip or at worst the portion protruding from the collet.
An incorrectly assembled torch is also a possability- there was a recent thread where it turned out someone had managed to fit the collet in backwards... http://www.mig-welding.co.uk/forum/showthread.php?t=26211&highlight=collet
Post a pic of the material, looks like cold rolled/reduced to me but it'd be easier to tell without weld spatter, soot etc.
Have you tried the spot weld test Paul suggested? Granted it won't be probative if the steel is coated/plated but typically gas issues cause more grief than coated/plated/dirty material
An incorrectly assembled torch is also a possability- there was a recent thread where it turned out someone had managed to fit the collet in backwards... http://www.mig-welding.co.uk/forum/showthread.php?t=26211&highlight=collet
Post a pic of the material, looks like cold rolled/reduced to me but it'd be easier to tell without weld spatter, soot etc.
Have you tried the spot weld test Paul suggested? Granted it won't be probative if the steel is coated/plated but typically gas issues cause more grief than coated/plated/dirty material
Haven't had a chance to check for gas leaks yet but I tried again; cleaned the sheet with a flap disk to BARE metal. I did try and take a pic of that and the pic came out real bad but I promise, it was bare metal.
The pics:
1. The metal cleaned.
2. The tungsten 'before, 1.6 mm'
3. The stickout
4. First bead at 70 amps
5. Second at 70 amps (bottom) and third at 80 amps (top)
6. This is other side of the third 80 amps to show the prenetration
7. The tungsten after three beads. As you can see, it's appalling.
Still looks like some contamination though. But I know that the gas is flowing.
Also, I didn't add any filler. I'm just trying to control the arc for now.
Gas leak, wrongly assembled torch, anything's possible. I didn't think it was possible to put the collet backwards but will check.
I know the polarity is correct.
The gas itself - I guess there is no real way of knowing whether it is what it say it is on the label?
The pics:
1. The metal cleaned.
2. The tungsten 'before, 1.6 mm'
3. The stickout
4. First bead at 70 amps
5. Second at 70 amps (bottom) and third at 80 amps (top)
6. This is other side of the third 80 amps to show the prenetration
7. The tungsten after three beads. As you can see, it's appalling.
Still looks like some contamination though. But I know that the gas is flowing.
Also, I didn't add any filler. I'm just trying to control the arc for now.
Gas leak, wrongly assembled torch, anything's possible. I didn't think it was possible to put the collet backwards but will check.
I know the polarity is correct.
The gas itself - I guess there is no real way of knowing whether it is what it say it is on the label?
pedrobedro
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How long is your post flow set for? Rough guide is 1 second for every 10 amps and don't move the torch till the gas stops. The craters look like the gas is stopping too soon and the weld is oxidising and the tungsten points to the same symptoms.
My money's starting to move toward the gas. The cooling lines in the weld look a little long and odd too, perhaps since if it's got CO2 in the mix, then it's an 'active' gas - the CO2 does actually contribute heat into the weld?
Can you borrow someone else's argon cylinder to try it out? How long does it take for the tungsten to get like it does in your last photo? Did you crash it into the weld pool? (Sorry for the accusation!)
Can you borrow someone else's argon cylinder to try it out? How long does it take for the tungsten to get like it does in your last photo? Did you crash it into the weld pool? (Sorry for the accusation!)
Omniata
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I've had similar "discolouration" of my tungstens, I've put it down to the post flow only being about 3 or 4 seconds... But not quite as bad as that, but then again I am running at 100A...
Luckily I got in touch with the chap in China I bought it off and the post flow is set by a single 10K resistor, now to change it for a POT
Edit: With regards to the gas you'd see the tungsten frying if there was CO2 present, my set "stutters" occasionally and I've put it down to the odd spider that had found its way into the gas lines...
Luckily I got in touch with the chap in China I bought it off and the post flow is set by a single 10K resistor, now to change it for a POT
Edit: With regards to the gas you'd see the tungsten frying if there was CO2 present, my set "stutters" occasionally and I've put it down to the odd spider that had found its way into the gas lines...
Paul.
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Your amps are still too high, and you really need to check your gas flow , until you either eliminate or prove a problem with the shielding then you are wasting time trying to produce weld beads, here is the simple gas test illustrated and what you should expect to see from it
this is just an offcut of 2mm thick mild steel box section cleaned with a flap disk, set up your welder with a post gas flow of about 3 or 4 seconds after the arc stops,
Hold the torch vertical with a minimal arc gap, this is about 2mm with a 1.6 electrode, welder was set at 50 amps, with a flow of 6lpm
Strike the arc and hold the torch still until you see a molten pool, then trigger off and hold position till the gas flow stops, if your gas flow is correct and uncontaminated it should look something like this, ignore the pinhole in the middle, remember this is without filler, you can clearly see the circular area protected by the shield, surrounded by the unprotected tinted area outside the cup, a bigger cup or a gas lens would probably have almost eliminated the blued area.
Just to show the effect of the post flow, on this one on the right I moved the torch away immediately the arc stopped
this is just an offcut of 2mm thick mild steel box section cleaned with a flap disk, set up your welder with a post gas flow of about 3 or 4 seconds after the arc stops,
Hold the torch vertical with a minimal arc gap, this is about 2mm with a 1.6 electrode, welder was set at 50 amps, with a flow of 6lpm
Strike the arc and hold the torch still until you see a molten pool, then trigger off and hold position till the gas flow stops, if your gas flow is correct and uncontaminated it should look something like this, ignore the pinhole in the middle, remember this is without filler, you can clearly see the circular area protected by the shield, surrounded by the unprotected tinted area outside the cup, a bigger cup or a gas lens would probably have almost eliminated the blued area.
Just to show the effect of the post flow, on this one on the right I moved the torch away immediately the arc stopped
This.
To add to what Paul said the tungsten will also tell a tale i.e. an argon/CO2 blend will pretty much immediately oxidise the tungsten (CO2 is dissociated into CO and O2 in the arc) and a leak in the system can have the same effects by drawing air in. The primary role of post flow is to protect the tungsten as it cools from white hot, if all is good it should remain free of hint tint colours
Only just saw Paul's suggestion now so I will try that tomorrow. The post flow is set to about 6-7 seconds and I don't move until that stops. I do have one of those small disposable argon cylinders so I could try that.
I checked everywhere I could find for a gas leak. No bubbles or froth anywhere.
All that being said.....now for the 'idiot award'....
Remembered what someone said about incorrectly assembled torch and turned the collet around. BIG difference! I have no pics yet though but the tungsten looks a lot better and no contamination (I think anyway).
I am sincerely hoping that was the problem all along and if it was, I will proudly pronounce myself the 'welding knob of the year'.
In my defence, "the manual" was four photocopied pages in the worst chinese ingrish I have ever seen with no pictures. I did try and look for pictures elsewhere.
I deserve whatever s***e given and will happily accept.
I will say this though; I cannot tell you all how much I appreciate all the advice given. If it wasn't for you guys, I would be nowhere with this.
Will try Paul's test tomorrow with pics.
I checked everywhere I could find for a gas leak. No bubbles or froth anywhere.
All that being said.....now for the 'idiot award'....
Remembered what someone said about incorrectly assembled torch and turned the collet around. BIG difference! I have no pics yet though but the tungsten looks a lot better and no contamination (I think anyway).
I am sincerely hoping that was the problem all along and if it was, I will proudly pronounce myself the 'welding knob of the year'.
In my defence, "the manual" was four photocopied pages in the worst chinese ingrish I have ever seen with no pictures. I did try and look for pictures elsewhere.
I deserve whatever s***e given and will happily accept.
I will say this though; I cannot tell you all how much I appreciate all the advice given. If it wasn't for you guys, I would be nowhere with this.
Will try Paul's test tomorrow with pics.
Well done chap - especially for persevering.
If it's any help, and it is a very similar machine, here's a link to the RTech manual (160A ACDC) - it may be slightly better written. Be careful on the AC balance though, there is some debate that it may be stated the otehr way round.
http://www.r-techwelding.co.uk/Downloads/Tig_Welder_Owners_Manual_TIG161.pdf
Hope this helps, and hope you're back on track now,
Francis.
If it's any help, and it is a very similar machine, here's a link to the RTech manual (160A ACDC) - it may be slightly better written. Be careful on the AC balance though, there is some debate that it may be stated the otehr way round.
http://www.r-techwelding.co.uk/Downloads/Tig_Welder_Owners_Manual_TIG161.pdf
Hope this helps, and hope you're back on track now,
Francis.
Thanks all. I do have the R-Tech manual and its pretty useful. I also got the Miller GTAW handbook, just arrived today so I'm busy reading atm.
I do think I am getting on track if ever so slowly. I'll have to put it down to 'lesson learnt' and every mistake made is a lesson. I won't give up on this, intent on getting half decent at least.
Thanks again to everyone of you.
Cheers,
L
I do think I am getting on track if ever so slowly. I'll have to put it down to 'lesson learnt' and every mistake made is a lesson. I won't give up on this, intent on getting half decent at least.
Thanks again to everyone of you.
Cheers,
L
Last question for now (promise)
I did Paul's test. Not sure if good or bad (not as good as his I think). Please let me know.
Did three more beads; 70 Amps, 1.6 mm tungsten, 7 litres/min.
Plus a pic of the tungsten 'after'. Its still as pointy and smooth but has some miscoloring.
Hoping for feedback, good or bad. Please be brutally honest or I will never improve.
I did Paul's test. Not sure if good or bad (not as good as his I think). Please let me know.
Did three more beads; 70 Amps, 1.6 mm tungsten, 7 litres/min.
Plus a pic of the tungsten 'after'. Its still as pointy and smooth but has some miscoloring.
Hoping for feedback, good or bad. Please be brutally honest or I will never improve.
Drains
Yeah, nah.
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That's better! Your control will benefit from a sharper point on the tungsten - length of point, 2.5 (or more) x the diameter, (note the sharpness of TIG Paul's point above).
BTW, other's honest brutality won't make you improve, practice will. And don't be shy of trying out different amp settings. Again, note Paul using 50A above, on 2mm thick section. Try 50A or a shade more on your 3mm. See if the welds look less cooked.
BTW, other's honest brutality won't make you improve, practice will. And don't be shy of trying out different amp settings. Again, note Paul using 50A above, on 2mm thick section. Try 50A or a shade more on your 3mm. See if the welds look less cooked.
