Thread: TIG welding T joints

Originally Posted by spudboy

Well I got my TIG and am pretty impressed with it. It is SO quiet compared to MIG welding, quite like welding with gas actually. A lot slower and more controllable than MIG also.

After a bit of practice on mild steel I can do nice butt welds and lapped welds.

However - I need to know the secret to doing T joints - i.e. right angle joints. I tried extending the tip out a bit further from the head, and varied the amps (higher seemed to be better). I also tried a pointed tip (by grinding it) and a flat tip (by snapping it off clean). I had more luck when the joint was vertical then when it was flat on the bench.

The main problem seems to be the "flame" wandering away from the base of the joint and up the sides or across the bottom of the joint.

Any advice happily received.
Thanks
David

BTW the steel I was using was 2.5mm bar cut into small 100mm pieces. Tungsten tips used were 1.6mm (which burned and melted quite a lot) and 2.4mm. Amps varied between 75 and 130.

So what sorta tig are we talkin just a dc jobbie for doin steel/stainless ....

You need to sharpen the tungsten the right way too the grind marks should run parrell with the tungsten not arround and the point should be sharp and neat this will stop the arc wander you have ...

As for stick out you dont need much say 8 to 10 mm is ample tho ive used mine with near 2 inches hanging out and gas flow at max welding inside a hole

I ground the tip by holding the electrode in line with the grinding wheel, not from the side, so the grooves were parallel with the electrode.

It is a Kemppi pulsed AC/DC 230A. I was using it DC negative. Thought I'd start with something simple before moving onto Aluminium.

I was only sticking the tip out 2 or 3 mm. I will try more. If it doesn't stick out far it is hard to get it into the "V" of the joint but 8 or 10mm sounds a lot! I will give it a try. Thanks.

Also, I didn't grind the tip to a real point, but I left the end "flat" (like a cone with a bit chopped off the end).

Originally Posted by spudboy

Also, I didn't grind the tip to a real point, but I left the end "flat" (like a cone with a bit chopped off the end).

Nope ya need a sharp point and it will work best also are you using thoriated or zirconiated tungsten either red on the end or white/blue

I don't know the tech name, but they are the red ended DC ones. I have got some white tipped ones for the Ali.

I'll try them with a sharp point next time. The Kemppi manual suggested to leaving the end flat so I just followed that.

Do you think 1.6mm is to small for those Amps and that sized steel? It seemed to eat the tip at 70A, whereas the 2.4mm electodes lasted heaps better.

just to be daft try a slightly chiseled point and aim it like you would if you were going to use a cold chisel to seperate the 2 plates of the T, Im not talking a gargantuan tip size chisel just shy of a mm should be enough and the few times Ive tigged (ARC/oxy is my norm) Ive always felt more comfortable extending the tip so I can see whats going on more easily and get the point right up close to where i want the arc to go.

Dave your on the money there buddy tho a sharp fine point is the go and i like to weld with this point about 3to 4 mm away from where im welding as it keeps the arc were it needs to be easyer ....

As for burning the tungsten id say your trying to weld with the tungsten to far away from the job like i said 3to 4 mm is the go and have the tip about 10mm out of the shroud ....

With practice you will be able to weld light gauge material with ease i can weld .5 stainless with about 35 amps with ease also with practice on ally you will be able to acheive good results on light gauge alli ....

When i did my apperenticeship at tafe we had a play with coke cans and i was able to weld a coke can with the tig using 1mm alli mig wire and verry low amps but i did it no worries tho it took sum practice to get the amps right ....

I've been doing some reading on this problem and a number of people have mentioned not to use welding magnets because they distort the flame.

I was holding all of this together at 90 degrees with a dirty big welding magnet, so that may be contributing to my problems.