# TIG Expert, what do you think of that



## jfdupuis (Sep 10, 2009)

Hi all,

As I'm always seeking for improvement, I wanted to ask the good TIG welders their opinions about my beads. It's hard for me to find go welder nearby to show my welds, and since it seems that some guys around here have a pretty good eye, I dare to ask for criticisms. I'm felling comfortable to weld but I'm still seeking better weld esthetic. Any piece of advice would be appreciated.

The parameters were:
Wall : 0.7mm (0.028"), Columbus Niobium
Tungsten : Lanthanated (Black) 1.6mm (1/16")
#7 Nozzles with 10 L/min of argon (21.5 CFH) no gas lens
Max pedal current was about 40A to start, so running bead probably in the 20-30A range


Thanks,

Jeff


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## Walt (Jan 23, 2004)

*Gas lens, less heat, more practice*

-Get a gas lens.
-Move faster, use less heat, or some combination of the two.

This joint is way overcooked and you're not getting good shielding - the weld should be shiny/rainbow colored, not black/grey. That's oxygen reacting with the metal, so you've got to make sure the shielding gas gets there and stays there until the metal has cooled enough not to react.

Keep practicing!

-Walt


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## mattty (Feb 26, 2009)

I dont see any small scratches from mechanical cleaning- (using a light gauge wire brush on a drill)

And the thumb prints might be from after welding/cutting, but make sure to use denatured alcohol to clean prior to welding as well... and don't touch the area after wiping down. Pretend your doing surgery.

Use the biggest cup you can, whenever possible. Dont let the tungsten out _too_ far. Have a post flow of at least 8 seconds. Clean any scale off before starting a new bead...


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## jfdupuis (Sep 10, 2009)

Walt said:


> The weld should be shiny/rainbow colored, not black/grey.


This is exactly why I'm posting here ! I've played with the parameters and still feel that gas shielding is problematic. I'll try with heat turned down and the lens is sure on the buying list.

That's a new setup I have and I'm not trusting anything. I'm coming back to welding after a 10 years break, and I don't remember struggling that much with shielding back then on a different machine. Is there a way to verify the setup ? On a simple and easy accessible join like this one, even without a gas lens, I would expect a more decent results.

As for the cleaning, I use acetone to remove any contaminant. I forgot once to clean them, and it was bubbling crazy. So, without cleaning, this is a no go !


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## mattty (Feb 26, 2009)

Have you tried putting the CFH closer to 30? Without a gas lens, it might be necessary... I know some have said that it forces turbulent, unwanted air in. But it's been my experience that its the only way to adequately shield. (a gas lens is sometimes too large to fit between stay braces)


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## Rody (Sep 10, 2005)

Jeff,

Walt's advise is sage and to the point as are Matty's contributions regarding cleanliness. However, I don't want you to feel like you have to run out and buy new equipment to weld under your parameters, you just need more time behind the helmet working with thin materials.

When I got home this morning, I set up my equipment to similar specs with minor changes:

Thoriated 3/32 tungsten
Standard cup at 12 cfm
Straight amperage with max pedal at 80 amps...running around 20-30

The key is to have proper torch angle, consistent speed and filler angle/position based on the fill requirements of the joint. 

When working without a gas lens, I hold the torch in such a way that my hand cups behind the torch, aiding in pooling the argon and restricting turbulent in flow of oxygen. Additionally, do a few dry runs to test your hand positions, length of appropriate travel, and filler angle before stepping on the pedal...this will help you determine a weld path and distance so that you may run the bead without staying too long in an area to reposition, add filler, and will aid in avoiding overextending your range of motion and efficiency.

Welding with straight current is much like running on a fence, a delicate balance of control, speed, and adjustment where you must be attentive to all variables, compensating for them on the fly. As much as I hate to admit it (don't snicker Carl), a pulser does aid in controlling these variables on thinner material by allowing less accumulative heat input...a fine option to explore once you've mastered the tips stated from all contributers above.

Keep working on it, you will get the skills back in time :thumbsup:


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## jfdupuis (Sep 10, 2009)

Thanks all for the valuable input so far, that will really help me to tune my technic. At the end of the afternoon, I passed by the weld supplier and found a gas lens. It was cheaper than I expected and will try it soon. Since I never tried one, I'm very curious about it.

That weld you post Ruby is exactly what I want to achieve. Seems that I have some gas to blow to get there. 

Looking at the parameters you posted, 3/32" for the tungsten, isn't a bit big ? I was heading toward the 1/16" or 0.040". Also, 12 CFM ? I hope you meant CFH, if not, my tank will get down quick. 

I was also wondering what size of filler you guys use. From what I understood from Columbus, they suggest to use the OK Tigrod 13.12. The smallest I was able to find was in the 1/16" and now questioning if this wouldn't be too big.

Jeff


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## j-ro (Feb 21, 2009)

Nice work Ruby 
Thanks for taking the time for an in-depth and informative response. That was cool

@Jfdupuis, If you can't find smaller than 1/16" at your local weld supply you can buy a small roll of Mig wire in either .045" or .035". That beautiful little bead in the picture above looks to me to be .045"


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## Rody (Sep 10, 2005)

Jeff,

Quick answers before I'm off for the day...

The size of the tungsten simply limits your top end of the heat range...has very little to do with the lower end as long as you have a good tapered vertically ground point that directs the current to the tip. I find that 3/32 allows for a better range of variation and control while working around a joint, permitting sufficient range of amperage to move from deep "v's" where more heat is necessary due to the increased surface area to a wider, more bridging puddle on the outside ears or overlaps. Wide changes in amperage simply put a smaller tungsten through a greater span of physical change for it's size...the 3/32" tends to be more stable within the same range due to it's physical mass.

The filler used in the above weld is .035...the magnification of the pic makes it difficult to discern. I rarely vary from this size, mostly because I buy in 10 pound quantities so have an abundance to use, choosing instead to change the feed rate and heat input based on the conditions required.

cheers,

Rody


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## customfab (Jun 8, 2008)

mattty said:


> Use the biggest cup you can, whenever possible. Dont let the tungsten out _too_ far. Have a post flow of at least 8 seconds. Clean any scale off before starting a new bead...


8 seconds? If you need to post flow for that long you are doing something wrong. Half of that is plenty. Did you mean 30 cubic feet per minute? That is a lot of gas for such low amperage and .5 cfm obviously isn't enough.


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## jfdupuis (Sep 10, 2009)

customfab said:


> Did you mean 30 cubic feet per minute? That is a lot of gas for such low amperage and .5 cfm obviously isn't enough.


Mattty wrote 30 CFH, which is 0.5 CFM. So, you are saying the same.

I'm heading to the workshop and I'll try to make good use of the valuable input you provided to get my weld right.


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## D.F.L. (Jan 3, 2004)

Just like Walt said, you're putting too much heat into the work. This may not be due to the amp setting you have (I'd probably run 35 for that material, pulsing manually) but instead because your lack of expertise is causing you to spend TOO MUCH TIME trying to get the beads down. I run sub-10CFH and a 7 cup on a gas lens (but I welded just fine without the lens). With skill comes speed, but you mustn't TRY to go quickly. And your weld is much larger than needed.

There's so much heat in your piece that it's oxidizing after it emerges from the shielding gas. Small, cool welds don't stay hot long enough to do that.


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## mattty (Feb 26, 2009)

customfab said:


> 8 seconds? If you need to post flow for that long you are doing something wrong. Half of that is plenty. Did you mean 30 cubic feet per minute? That is a lot of gas for such low amperage and .5 cfm obviously isn't enough.


My (sans gas lens) setup was: 30 CFH with a post flow of ~8 seconds for tubing .9-1.2mm thick welded to BBs and HTs 1.5-2mm thick...

Here is an established company's work, which looks to me to be too much heat and inefficient shielding:

https://4.bp.blogspot.com/-58p_I3UNK84/TbIplpV-TSI/AAAAAAAAAIw/eMgmJxXQyV0/s1600/IMG_8475.JPG

Is this much scale/oxidization acceptable? The stays are .089" I believe.


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## D.F.L. (Jan 3, 2004)

Probably a little hot, but you'll also get front-side oxidation when doing back-side welding, unless you make some sort of shielding rig.


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## jfdupuis (Sep 10, 2009)

I'm back from the workshop and it seems that I got it right now. I still have some tanks to go through to get beads as uniform as the one posted by Rody, but I solved the oxidation problem. 

As few said, I was over heating my part. The full part was getting too hot. Therefore, as D.F.L mentioned, it was oxidizing after it emerged from the shielding gas.

I think I was over heating because my filler was too big. I was using 1.6mm filler and it required way too much heat to melt against the 0.7mm walls. Trying with some random 1.0mm filler was a revelation. With the same parameters, I was getting oxidized welds with the 1.6mm filler, while the 1.0mm filler was giving me nice colored bead. 

The gas lens was interesting. It seems that I could extend the tungsten way beyond what I would normally dare too in order to access tight corners. 

So, thanks all for your input. It really helped to find out what was wrong. At least now the parameters seems right. Still need to get those beads uniform, but only practice will get me there.


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## Rody (Sep 10, 2005)

Jeff,

Glad you have been successful in dialing it in.

Make sure to post some progress shots, always self affirming when you can see the physical difference resultant to the changes you've made in process and set up.

cheers,

rody


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## jfdupuis (Sep 10, 2009)

Rody,

I'll certainly post some pictures back. While they are now shiny and full of color, my beads are still haven't reach a level that I would be proud to post. The picture you posted really sent me back to the training bench. 

I'm still struggling to obtain really well defined rounds. My bead shapes are still flat as the original picture. 

I discovered the pulse on the machine. Since I've learn to weld on an old machine with the size of a fridge, setting all the related parameter on this lunch box was quite a jump in the new century. Took me a while to get the beat, but it seems that the pulse help to avoid overheating. It also give you a nice metronome beat. But still no stack of dimes ...

Jeff


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## j-ro (Feb 21, 2009)

Jeff,
Instead of trying to make a stack of dimes with the pulser do this; 

turn the PPS up to around 150.

once you develop the puddle, move forward at a slow steady pace,

as you are moving ,stab in the filler rod. 

this will cool the puddle, build up the material and create the first 'stack'

as you move past it, it will hollow out and create a space for the next stab of filler rod.

the eveness of your travel speed, the timing of adding your filler, the amount of filler are all things that play into the finish of the weld.

don't get discouraged if you can't lay down 2" of perfect weld, instead try to get 5 nice little dimes in a row. when you get that, shoot for seven.

good luck.


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## customfab (Jun 8, 2008)

jfdupuis said:


> Rody,
> 
> I'll certainly post some pictures back. While they are now shiny and full of color, my beads are still haven't reach a level that I would be proud to post. The picture you posted really sent me back to the training bench.
> 
> ...


Your first sample looks like haggard hell and you posted it. We are here to help, but it's hard to do that without pictures.

In my opinion you should learn to weld without the pulser. It's a good tool but it's a bit of a crutch as well. Once you can get something that lays down smooth and doesn't have lots of suck back then you can play with the pulser.


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## jfdupuis (Sep 10, 2009)

*Training update*

Hi all,

Here is some picture update on my welding training. I'm running out of training tube so, I had to go with some sheet metal. Everything is 1mm (wall, filler, tungsten), gas lens with 10L/min. I didn't use the pulse and my pedal broke, so no on the fly current adjustment. The first bead on the left was done at 60A. I felt that this was too hot, so I did the second one on the right at 45A.

My bead are always very flat like these. From the picture previously posted, it seems that bead have normally more relief. Having flat weld is actually quite nice for the finish, but not sure if it is correct welding technic. What I'm more concern is the concave surface of the weld bead. As I understand, concave bead surface will have more tensile residual constrain than convex one, which can lead to easier crack propagations.

Regards,

Jeff


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## j-ro (Feb 21, 2009)

Hey Jeff,
looking better.

couple things, 
one- that type of joint will tend to lay in with more concavity than usual anyway. if you want to try for something rounder try laying the vertical piece over at an angle. It will give you more room for your torch too.

two- you may have too low of a torch angle, looks like you may have it laid over more than 45*. Hold it straighter up and down, like more between 60-75* and keep it at there as you move over the weld

three- you are starving the puddle, give it more filler- it's getting too hot and that leads to the sugar on the back side. 

four- stay after it and post more pictures!


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## mexi mike (Jan 20, 2009)

j-ro said:


> Jeff,
> Instead of trying to make a stack of dimes with the pulser do this;
> 
> turn the PPS up to around 150.
> ...


Doesn't really pertain to this thread, but if your stab filler in you will get raised ripples like the picture you posted. When adding filler it is important not to stab (till you feel resistance) because you cool and disfigure the molten pool to irregular. For a smoother finish, tapping the filler in at the surface of the pool works best. Remember welding is just on site casting. If you can't get enough filler into the pool by just tapping it in at the surface, you have 2 options, increase your filler cadence or increase your filler rod size. Take it for what it's worth, welding especially TIG is an evolving art that has no perfection.


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## j-ro (Feb 21, 2009)

mexi mike said:


> Doesn't really pertain to this thread, but if your stab filler in you will get raised ripples like the picture you posted. When adding filler it is important not to stab (till you feel resistance) because you cool and disfigure the molten pool to irregular. For a smoother finish, tapping the filler in at the surface of the pool works best. Remember welding is just on site casting. If you can't get enough filler into the pool by just tapping it in at the surface, you have 2 options, increase your filler cadence or increase your filler rod size. Take it for what it's worth, welding especially TIG is an evolving art that has no perfection.


 Thats good info Mike thanks, my description to jeff was more of a way to have him get the gross motions and components of the weld down vs. spending a paragraph explaing the introduction of filler rod. I knew the word 'stab' was crude when I typed it but I figured it would get him going in the right direction.

Your comment about welding being an evolving art is a great statement-so true, I agree.

It's also important to note that welding style is very individual as well. There are as many styles as there are welders. I'ts good to look at someones weld as a target but do it knowing that ulitimately your's will look a little different. This is true for all types of welding, not just tig.


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