Is there a trick to welding a T-joint?

[Mr-Mike]

I will try to use the lingo. For the life of me I cannot get a root pass fillet weld on the inside corner length of a T-joint. Just working with 1/8" (3mm) cold-rolled low carbon steel. Running around 120Amps, 3/32 2% Lanth, 1/16 ER70S-2, 18cfh, #8 cup. I tried dabbing then lay-wire. I mostly get globs on both faces either side of the joint. I did get a couple of centimeters of weld actually in the corner joint (at the point of intersection) but that apparently was luck.

Is there a technique I should know about?

My profound appreciation in advance.

 

[Paul.]

All in the tig tutorial, but it sounds like you need to learn to keep your arc length shorter.

https://www.mig-welding.co.uk/tig-fillet-weld.htm

 

[Brad93]

Pictures speak a 1000 words.

 

[Richard.]

If your filler wire is balling up and your pool is not forming in the corner then two simple steps will help you out.
Turn up the juice. 120 is minimum for a 3mm fillet.
Keep your arc focus right in the corner. A short arc is much cooler than a long arc with regards to the heat effects on the job. This means keeping it tight will allow you to up the juice and then you’ll find that filler just hits home every dab. As soon as you increase the arc you will start cutting the plate away and melting the filler across it before it’s even had a chance to make it to the pool.
Fillets are tricky when starting out. Get some butt joints nailed first to master that short arc.

 

[Mr-Mike]

Right! the tutorial - awesome. Thank you.

Pictures --> or at least a few laughs. As requested Sir.

Richard, that's exactly what is happening, (I think ). I didn't know why though. Arc length was long (as played back in my mind) and the effect as you described is reflected in my results. I was afraid to increase the amps because I was already melting material away. Looking forward to executing your advice. My gratitude! I tried some butt joints, they did work out better, enough so to see the progression path you recommend.

 

[Mr-Mike]

The somewhat evenly spaced balls in the top pic was the laywire - haha.

 

[Liquid Metal]

To help keep a short stable arc length, if youre welding fillets, try changing to a #6 ceramic if you have one, gives you a little less less of a stickout.
Should help you keep a shorter arc length, and wont affect gas coverage as the gas is trapped in the fillet due to the shape of it. (Will also make it a bit easier to see what youre doing).
Cant tell you why, but it really is "sub-consciouslly" easier to hold a shorter arc with a touch less stickout than a large ceramic with a long stickout.

Also, another way to set you stickout while you get to grip with things, is hold the torch "square-on" to the joint (still at 45deg though) so the tip of the tungsten is sitting almost right in the corner, maybe a mm or 2 away from the very corner.
That way, when you're running the weld in the fillet, using your 10-20deg or so torch angle, youre not going to be thinking of dipping the tungsten as the ceramic will bump on the plates first, so will straight away be able to hold a shorter arc.
Another thing which helps a great deal, is relax your hands, arms and shoulders so youre comfortable

 

[Liquid Metal]

Focus on the dabbing technique with a steady, constant travel speed for now.
Trying to learn 2 techniques together is just making it harder than it needs to be.

Using laywire techniques is something to go onto once you get a bit more confident as it does work better using higher amperage settings and travel speeds, and the feeding of the wire is a bit different (ie it's not simply hold the wire there and run the torch over it).

 

[Mr-Mike]

@Liquid Metal; Sounds great, will give those a try. Appreciate your comments!

I did some more earlier, being mindful of Richard's advice, vast improvement Also, I said before I tried a butt joint, but it was actually a lap joint - just for the record. I will try a real butt joint next.

Cheers!

 

[Mr-Mike]

some improvement with practice. Still not comfortable but I might actually be on the right path. Top pic is the T though the camera makes it look flat, to me anyway. The hard part for me is maintaining smooth constant torch speed and rod travel over the length of the run along the corner, and maintaining torch position as the angle of attack wants to naturally change moving from one end of the bead to the other. It requires constant adjustment. Not much room for correction in the "T" either. You are either on point or not and weld goes to heck. Maybe I am just too rigidly seated but more likely it's just torch control. Plain beads and butts (true butt not lap, lol) are feeling better.

 

[Tom_ERST_S2]

some improvement with practice. Still not comfortable but I might actually be on the right path. Top pic is the T though the camera makes it look flat, to me anyway. The hard part for me is maintaining smooth constant torch speed and rod travel over the length of the run along the corner, and maintaining torch position as the angle of attack wants to naturally change moving from one end of the bead to the other. It requires constant adjustment. Not much room for correction in the "T" either. You are either on point or not and weld goes to heck. Maybe I am just too rigidly seated but more likely it's just torch control. Plain beads and butts (true butt not lap, lol) are feeling better.

Best thing to do if things start to run away and torch angle goes to pot is simply back off the power and reset. There’s nothing wrong with doing a run in steps if you can’t do all of it at once. It’ll look a lot better than a continuous run that has heat spikes and sunken areas.

 

[Mr-Mike]

I have no idea why I needed some one to say this but I am glad you did Tom. I do have a foot pedal and I use it (with minimal success) to try to prevent myself from getting out of control. It is very sensitive. I can see the benefit when properly applied though. My pedal-work needs finesse. A little movement, a few amps, has a significant affect on the weld. I am going to lighten a bit and get started making something. First on the list is outdoor shelving for plants. 72 feet of 1 inch square tubing and expanded steel for shelves (flat). While am typing, I might as well ask if there is anything I should do or watch for when welding the expanded stuff (aside from obliterating it with amperage)?

Thank you!

 

[Richard.]

I have no idea why I needed some one to say this but I am glad you did Tom. I do have a foot pedal and I use it (with minimal success) to try to prevent myself from getting out of control. It is very sensitive. I can see the benefit when properly applied though. My pedal-work needs finesse. A little movement, a few amps, has a significant affect on the weld. I am going to lighten a bit and get started making something. First on the list is outdoor shelving for plants. 72 feet of 1 inch square tubing and expanded steel for shelves (flat). While am typing, I might as well ask if there is anything I should do or watch for when welding the expanded stuff (aside from obliterating it with amperage)?

Thank you!

Mike my advice is leave the T joints. Get the fundamentals sorted out on flat plates and butts. Don’t move on till every weld looks spot on. Arc length mate. That’s all you need. Put the pedal away mate. It’s of no use to you on dc. You need a fixed consistent current. Amps up and down makes your fusion go up and down.

 

[Mr-Mike]

I hear that Richard, and it sounds good to me. I do want to get the basics down solid. Right now, arc length and torch angle takes a lot of concentration. I want it be 'automatic' and effortless, AND comfortable. I am always struggling with positioning - me, the torch, the workpiece, the rod, the clamps... I won't miss T-joints for a while, besides I am already proficient at grinding Tungsten - lol. Foregoing the 'T' joints for awhile will keep me at the table instead of the grinder.

By the way Richard, recalling your comment on the Fronius torch, I have never touched any other torch but find myself wanting something narrower and concentric - go figure. At least the electrode part swivels. That makes it workable. Depending on how I arranged my workpieces I find I hold the torch 2 different ways; grab it from the top (palm down) like a motorcycle grip, or from underneath like a writing with a pen. There's actually a question there. Is there a wrong way to hold the torch or is 'what works' the right approach?

On the pedal, 99% of the time I used just like a 2T switch. I set my amps at the machine, put the pedal to the floor and hold it there until the last dab. I like easing off the pedal and watching the arc shrink away. What I would really like is a welding helmet with a HUD for amps and volts. There really wouldn't be much to adapting HUD. I would love to know what I am drawing when I do work the pedal. I haven't tried the torch switch yet to be honest, and Brad said the same thing about not using the pedal. Truth is I have yet to set the slope other than what may be default and didn't want to bother figuring it before my first try. The pedal seemed to work well enough so I just continued with it. I will set it up and give the switch a try - it will be interesting, something different.

I will say I need to run some Al though I am clearly not 'there' yet. I am too curious and have to try it. I have been putting it off and its the main reason I went with TIG.

Cheers and huge thanks!!