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trouble welding tubing

Posted: Mon Jul 27, 2015 12:13 am
by scook1940
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Hello my name is steven I have been tig welding about 4 months now. I currently use the miller synchro wave 210. When I'm welding on some 1 1/2 .120 wall mild steel tubing it doesn't look right I knotched it and cleaned with acetone. The welding was dine at 60 to 85 amps with about 13 to 16 cfh with a 2% lanthanated tungsten.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 12:20 am
by scook1940
Ah sorry the amps were 95 to 110 in between that range

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 5:46 am
by motox
looks like you are having trouble
moving around the weld keeping
the proper torch angle.
it takes a lot of practice to
weld tubing joints.
craig

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 7:58 am
by Boomer63
With a joint like you have here, you start the weld half way down each side and work up. Sometimes you stop at the 'flat' part near the top, sometimes go all the way to the top.

From looking at your pictures, I would check your movements and angles. Take a few minutes, with the machine off, to really, really, really get the feel for what you are doing. Take a few 'dry runs'. Take your time with this, it is important. Try moving up your amperage a bit .. 100 +. Move fast! Dip the rod, don't lay wire.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 1:15 pm
by Oscar
I agree, the only trouble you're having is you need more practice welding round tubing using the proper practicing techniques. It's tough, done it a few times. To keep the proper torch angle takes a lot of practice and learning.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 1:46 pm
by scook1940
That was my first time welding round tubing with tig I wasn't sure what to keep the torch angle at.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 2:28 pm
by Oscar
scook1940 wrote:That was my first time welding round tubing with tig I wasn't sure what to keep the torch angle at.
for T-joint like that you would be at 45° at the inside corners (assuming same material thickness), with just a slight tilt forward to wash the puddle ahead a couple of mm. On the outside flat part, you want to melt a little of the coped tube edge, but not too much. It takes A LOT of concentration to learn the muscle memory into proper hand coordination because the torch angle is ALWAYS changing. Do dry runs, then get a look at your torch hand as you hold it in position and stand up and look around from different angle to see if you are not tilting it too much in any one particular direction. I'm not an expert by any means, so I can tell you it is tough if you're barely starting out, or do very few of these joints such as myself.

Also you might want to start getting into the proper habit of grinding off the millscale from the outside & inside of the tubing on mild steel, if it is hot-rolled and has a heavy layer of it. It makes the puddle sluggish a bit, and does not help at all with TIG welding. Coarse flap wheel on an angle grinder, and a 1" aluminum oxide grinding stone (small cylinderical one) on a small die grinder for the inside will help with learning proper technique. The puddle becomes more fluid so you eventually have more control over it as you get better.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 3:03 pm
by big gear head
Get you a TIG finger from the weldmonger store so you can prop your hand on the tube without burning it. Then practice practice practice. Just run beads around the tube over and over so you don't use a lot of material. Try to keep the tungsten pointed as straight into the puddle as you can. I tend to point the tungsten in the direction of travel and that makes the wire melt before it reaches the puddle, and the puddle gets oval shaped. I have to pay close attention to the way I'm holding the torch so that I don't point it ahead too much. Also be sure that you dip the wire into the puddle and not in front or to the side of it. I noticed that you missed a dip a few times in the pictures above.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 7:33 pm
by scook1940
Thanks I'll try it tonight when I get home I'm going to build a drift trike for my brother so I want the welds as best as possible.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 7:56 pm
by Oscar
scook1940 wrote:Thanks I'll try it tonight when I get home I'm going to build a drift trike for my brother so I want the welds as best as possible.
Then that means you are prepared to slice up your practice welds and etch them to view the fusion depth profile, right? ;)

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 9:50 pm
by zank
I think you're doing great! I'll echo clean to bright shiny metal, get a tig finger to prop comfortably on the tube, bump up your heat to get a more fluid puddle going, and practice practice practice. I would add that you are over-filling the joint, but worrying about that comes later. For now, focus on finding a smooth rythm. Get the puddle nice and fluid, add filler and heat to get the bead width you want, and push the puddle with the torch. Add filler to keep the puddle satisfied. You will need to push more wire per dip in the T-joint sections compared to the ears of the cope, which are more like lap joints.

Re: trouble welding tubing

Posted: Mon Jul 27, 2015 10:54 pm
by scook1940
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Didn't have much time do a few passes due to my son trying to play with my welder but I turned the amps up to 115 and tried to keep the angle about 45 I just ordered a tig finger it seems like it would definitely help

Re: trouble welding tubing

Posted: Tue Jul 28, 2015 12:48 am
by Rick_H
Practice makes perfect.... Tubing and piping are a learning experience.

Muscle Memory really helps, those dry runs will help train your hand eye coordination. It's all about a nice fluid, smooth path, torch angle and arc length are very critical

Re: trouble welding tubing

Posted: Tue Jul 28, 2015 10:26 am
by big gear head
It's kind of hard to remember when I was learning. That's been about 30 years ago. Seems like the thing that caused me the most problems in the early days was keeping the wire under the cup after a dip so it didn't get contaminated. Being able to see the puddle is extremely important.

Re: trouble welding tubing

Posted: Thu Jul 30, 2015 11:39 pm
by scook1940
Hey practicing today I haven't been able to much but I did get some time in so any thoughts

Re: trouble welding tubing

Posted: Fri Jul 31, 2015 5:43 pm
by zank
Is that sanded to bright shiny metal?