SS Exhaust pipe weld settings? (PowerTig 225LX)

Printable View

12-25-2011, 09:02 PM
Welderooni

SS Exhaust pipe weld settings? (PowerTig 225LX)

Happy holidays Everlast'ers,

I've been trying to weld some stainless steel exhaust pipe (ebay brand) with 316L rod, but I think something is wrong with my settings, technique, or torch setup because all my welds look like crap :? . Can you guys please critique my weld with tips on how to make them better? :D

Prep: Stainless Steel Brush on surfaces w/ acetone + paper towel cleaning.

Tungsten: 2% lanthanated (3/32 size), sharpened to a point
Amps: 40 (also tried pulsed @ 40/20)
Gas: 100% Argon
Torch: Air cooled Everlast
Torch Flow: ~7-8 L/min
Back Purge: ~2.2 L/min through the pipe
Tungsten protruding distance from #7 EverLast cup = 4.32 mm

http://i876.photobucket.com/albums/a...ooni/WeldA.jpg
http://i876.photobucket.com/albums/a...ni/WeldB-1.jpg
http://i876.photobucket.com/albums/a...ooni/WeldC.jpg
http://i876.photobucket.com/albums/a...ooni/WeldD.jpg
http://i876.photobucket.com/albums/a...ooni/WeldE.jpg
http://i876.photobucket.com/albums/a...ooni/WeldF.jpg
http://i876.photobucket.com/albums/a...ooni/WeldG.jpg
http://i876.photobucket.com/albums/a...ooni/WeldH.jpg
12-25-2011, 10:13 PM
performance

Your hand is very unsteady, and your dips are irregular. Chances are you need a smaller cup and a lot less stand off.

Don't use the foot pedal, if you are so you can maintain a constant heat. Try 4T to start. From the looks of it, the over reinforcement in the inside of the weld, shows me that you are putting in too much filler because you are overheating the metal...But its also curious, you are making large jumps forward, and in some ways it makes it look too cold.
12-26-2011, 01:20 AM
Welderooni

Thanks for your input performance! What do you mean by "stand off?" Is there a fast-stable way to have your pipe setup when back-purge welding stainless steel pipe? (Do you rest your forearms on the table? How is your ground clamp implemented?) Lastly, are there any cups better than the Everlast #7 ones you recommend for this SS pipe tig welding?

Here is my "from da hood" back-purging setup that I measured with the flow meter to make sure flow was accurate:
http://i876.photobucket.com/albums/a...dBackPurge.jpg
12-26-2011, 02:26 AM
zoama

1 Attachment(s)

Quote:

Originally Posted by Welderooni

Thanks for your input performance! What do you mean by "stand off?" Is there a fast-stable way to have your pipe setup when back-purge welding stainless steel pipe? (Do you rest your forearms on the table? How is your ground clamp implemented?) Lastly, are there any cups better than the Everlast #7 ones you recommend for this SS pipe tig welding?

Here is my "from da hood" back-purging setup that I measured with the flow meter to make sure flow was accurate:

Stand off in this case is arc length. Try to keep it at 1/8". I'd try more amps and travel faster advancing 1/8" each time at a constant speed to get the row of dimes look. If your tubing is 304 stainless you need 1/16" 308L filler.
I used parts from 2 everlast regulators to make a dual flow setup. Attachment 4311
12-26-2011, 02:22 PM
todmorg

Quote:

Originally Posted by Welderooni

Thanks for your input performance! What do you mean by "stand off?" Is there a fast-stable way to have your pipe setup when back-purge welding stainless steel pipe? (Do you rest your forearms on the table? How is your ground clamp implemented?) Lastly, are there any cups better than the Everlast #7 ones you recommend for this SS pipe tig welding?

Here is my "from da hood" back-purging setup that I measured with the flow meter to make sure flow was accurate:
http://i876.photobucket.com/albums/a...dBackPurge.jpg

If this T is after your flow meter, you are stealing torch gas for the backflow.

Stainless is easy to overheat.

Yes, you need to be well braced, I keep all kinds of odd sized blocks for hand rests. It is almost impossible to stand free hand and get a good looking weld.
12-26-2011, 09:19 PM
Welderooni

Hi Todd,

yes, the T-fitting is after the single-flow regulator. I set it up so that the backpurge valve is pulling a constant ~2L/min argon flow and when I hit the Pedal, the tig torch makes the flow meter go up to ~8-10L/min. So, my understanding is that phenomenon means that flow is going to the torch, but maybe I should raise the flow?

Also, how do you guys mount your grounding clamp to the pipe when backpurging stainless steel pipe like this? I used aluminum tape on both ends, with a slit on the outlet end and small hole for the argon tube on the inlet. But, where do you put the grounding clamp so that it's secure during this process? :O
12-26-2011, 09:25 PM
zoama

Quote:

Originally Posted by Welderooni

Hi Todd,

yes, the T-fitting is after the single-flow regulator. I set it up so that the backpurge valve is pulling a constant ~2L/min argon flow and when I hit the Pedal, the tig torch makes the flow meter go up to ~8-10L/min. So, my understanding is that phenomenon means that flow is going to the torch, but maybe I should raise the flow?

Also, how do you guys mount your grounding clamp to the pipe when backpurging stainless steel pipe like this? I used aluminum tape on both ends, with a slit on the outlet end and small hole for the argon tube on the inlet. But, where do you put the grounding clamp so that it's secure during this process? :O

Just ground your welding table...your work will ground through it.
12-26-2011, 11:33 PM
todmorg

Quote:

Originally Posted by Welderooni

Hi Todd,

yes, the T-fitting is after the single-flow regulator. I set it up so that the backpurge valve is pulling a constant ~2L/min argon flow and when I hit the Pedal, the tig torch makes the flow meter go up to ~8-10L/min. So, my understanding is that phenomenon means that flow is going to the torch, but maybe I should raise the flow?

Also, how do you guys mount your grounding clamp to the pipe when backpurging stainless steel pipe like this? I used aluminum tape on both ends, with a slit on the outlet end and small hole for the argon tube on the inlet. But, where do you put the grounding clamp so that it's secure during this process? :O

How are you setting flows? Are you setting the flow at 10L/M with the torch and then throttling the 1/4 turn valve to 2L/M with the torch off? Floating ball regulator?

My table is always grounded, but I keep a 2nd cable with 2 clamps for tubing or any low amperage work. One end clamps to the welders ground clamp and the other to the tubing. This stops any arcing between the the table and tube when rolling the tube during the weld.

You can practice without backpurge and then figure out your backflows, if you keep the heat low the back purge is not nearly as important.