How Am I Doing?

jbolt

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It has been 33 years since I last TIG welded. I have done my share of stick and flux core welding in that time but no TIG. I Just got an Alphatig 200x. Seems like a decent machine so far, at least for the casual welder.

At first I was having a terrible time seeing the weld puddle. I was using a standard #7 cup with 1/4" stick out. I switched to a stubby gas lens & cup and extended the electrode to 3/8". Made a huge difference.

This is 1-1/2" square tube with 1/4" wall. Root gap and face are 0.05". 3/32 2% Lanthanated tungsten, 1/16 70S2 filler for the root pass.

The left test piece was at 90 amps. The weld is a little fuller but it looked to me like it introduced too much heat into the part so I increased to 100 amps for the second test part. Seems about right heat wise but the weld is a little smaller. Maybe from moving faster?

20180421_103827.png


This is the filler pass. The left was done at 140 amps with 3/32" filler rod. I had trouble with pushing filler through the weld. Big glods developed under the welds resulting in some of the welds ending up shallow. I was having trouble controlling the filler rod for some reason. For the right side piece I reduced the amps to 130 and it was easier to control. Welds are mostly full except a little on the corners, no globs below. I still feel like I put too much heat to the parts.

20180421_110959.png
 
Jay... Looks good for the first shots with a new machine. The second of the two root pass tests looks nice. You got the heat down on that one.

For me personally, I use 3/32 electrode even for root passes because it's a slightly wider arc and you don't feel like you're doing surgery. For larger pieces like 1/4" wall, I feel 1/16 filler would be unforgiving. On each dab, it does not deposit much and therefore does not cool the puddle down so, you feel pressured to move real fast.

On the final passes, I think you were still too hot even at 130A. Are you using a foot pedal?

Anyhow, it looks good and you'll be kicking butt in no time!

Ray
 
Thanks Ray, my third test part went better. I was using 3/32 electrodes for all passes. I used the 1/16 filler for the root pass thinking the material is thinner here. On the third part I used 3/32 filler but had to increase the amps to 110 to get the filler to melt quick enough. The larger root weld helped with the filler pass. I'll get there. I went ahead and welded one of the parts form my large steady rest project. I'm happy with the results.

20180421_170009.png
 
You're getting it nailed pretty fast which is no surprise if you're coming back from a long TIG hiatus. Heck, I have to re-teach myself after 3 weeks, much-less 33 years.

The circle looks great! You did it in 2 sections and your pickup was really good. How is your wrist feeling?

That 3rd one is right in the pocket. You were doing real fast dabs with a steady advance. On the 3rd one, I see a little roughness that looks like boiling. Are you letting the part cool between welds? I'm guessing the part is holding a lot of heat and you're getting that porous finish. That also happens when scale migrates into the weld zone. On the middle one, you were poking/filling/advancing. Try that with an alternating side-to-side stitch; I think you'll like that and pull it off nicely especially if you've been doing a lot of stick welding.


You're on this like a duck on a June bug!


Here you go... I think you need to make one of these: https://www.hobby-machinist.com/threads/welding-rotary-table.64640/

So you can make circles.
1524360622000.png
 
Oh, BTW, are you using a foot pedal or just on/off?

Ray
 
You're getting it nailed pretty fast which is no surprise if you're coming back from a long TIG hiatus. Heck, I have to re-teach myself after 3 weeks, much-less 33 years.

The circle looks great! You did it in 2 sections and your pickup was really good. How is your wrist feeling?

That 3rd one is right in the pocket. You were doing real fast dabs with a steady advance. On the 3rd one, I see a little roughness that looks like boiling. Are you letting the part cool between welds? I'm guessing the part is holding a lot of heat and you're getting that porous finish. That also happens when scale migrates into the weld zone. On the middle one, you were poking/filling/advancing. Try that with an alternating side-to-side stitch; I think you'll like that and pull it off nicely especially if you've been doing a lot of stick welding.


You're on this like a duck on a June bug!


Here you go... I think you need to make one of these: https://www.hobby-machinist.com/threads/welding-rotary-table.64640/

So you can make circles.
View attachment 265748

Nice! Another project to add to the list (like I need more).
 
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