For the future. I know you've learned what causes the grey, but this might lead you to experiment. Anything under 1/16" in my industry is fusion (no filler)welded. Sometimes with a trailing shield. In food grade, chip plants, and pharmaceutical plants its usually done by an orbital setup. All are purged to zero oxygen and tested with a gas meter. Ive welded sch5 and 10 pipe which is thin with 45-50 amps and a #15 lense and got decent results on the outside, but the inside was silver. The inside of the pipe is what the company is really concerned with because its what contacts the product( your breathing air, pop tart dough, and Tylenol makings etc). Easy done with a good purge. A machine capable of pulsing would help tremendously, but I've rarely seen one on a job site. If anything I'd say good job and enjoy your exhaust.
Agreed. Even fusion welding alone is very strong. All of those bow rails on boats are thin wall and no filler at all. The welds are beautiful and even stand up to people crashing into docks, destroying the tubing right at the joints and the welds rarely fail.Otto Nobedder wrote:You'd think so,
But, no.
It's an exhaust system. In reality, it never sees measurable pressure. These welds only need to be leak-proof at atmospheric pressure, and the "sugar" on the back side has no real effect on ultimate strength.
Stainless exhaust systems are usually over-built.
Steve S
Also, learning to weld aesthetic quality on exhaust tubing is kind of counter productive. I think of all the tee's and laps I had to weld just to get the heat and travel speed figured out for consistent beads was a heap of stainless when it was all said and done. It was not uncommon to take almost a week to pass one simple joint test. Many tests were by hope and a prayer and just being glad the instructor did not make you do it again to make sure the good one was no mistake, which half the time it was pure luck, or getting to pick the best 'one' out of 20.
Miller ABP 330, Syncrowave 250, Dynasty 300 DX.
Honorary member of the Fraternity of Faded Tee Shirts.
Honorary member of the Fraternity of Faded Tee Shirts.
noddybrian
- noddybrian
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Hi - looking at your welds I have to say given the gauge of material ,your not doing bad if this is fairly new to you - I do thinnish wall tube for boat hand / grab rails & It's difficult to achieve consistently good looking welds with filler - it maybe me / eyesight / coordination - not sure but fusion welds are always way better - I try to plan the job & achieve fit up so this is possible
- this leads me to suggest you appear to be attempting butt welds on most of that pipe - therein lies much of the problem - because I use them on steam work I have a fair selection of tube expanders - if I have to make an exhaust I always expand one side of the joint for about 1" until it will slip over the other tube - I can then fusion weld around the step - it also produces smoother internal flow - if it is so close to a bend the mandrel of the expander won't go in far enough I would cut off a short piece of tube that fits snugly inside ( or split a bit of the same size & cut out enough that it can be reduced to suit ) so if it has to be a butt weld put the sleeve in & leave a slight gap so you can follow the join more easily - it doubles up the thickness at the weld & often can be a fusion weld.
You can be a very good welder - but sometimes how you approach the job is what makes it easy or difficult.
Hope this helps - good luck on the next exhaust.
- this leads me to suggest you appear to be attempting butt welds on most of that pipe - therein lies much of the problem - because I use them on steam work I have a fair selection of tube expanders - if I have to make an exhaust I always expand one side of the joint for about 1" until it will slip over the other tube - I can then fusion weld around the step - it also produces smoother internal flow - if it is so close to a bend the mandrel of the expander won't go in far enough I would cut off a short piece of tube that fits snugly inside ( or split a bit of the same size & cut out enough that it can be reduced to suit ) so if it has to be a butt weld put the sleeve in & leave a slight gap so you can follow the join more easily - it doubles up the thickness at the weld & often can be a fusion weld.
You can be a very good welder - but sometimes how you approach the job is what makes it easy or difficult.
Hope this helps - good luck on the next exhaust.
So, what you're saying is on thin sheet stainless like 16 gauge, only use overlapped material as the filler?
What about filling with silver solder?
Sorry if this is a hijack, but I'm trying to build gas tanks from 16 gauge stainless using a friend's Hobart EZ-TIG 165i and so far I'm not feeling the love. #10 cup, 3/32 red electrode, 1/16 308 filler and the electrode turns black almost immediately and a small bead of soot soon forms at the point.
What about filling with silver solder?
Sorry if this is a hijack, but I'm trying to build gas tanks from 16 gauge stainless using a friend's Hobart EZ-TIG 165i and so far I'm not feeling the love. #10 cup, 3/32 red electrode, 1/16 308 filler and the electrode turns black almost immediately and a small bead of soot soon forms at the point.
Check your shield gas. (Its not doing its job.)
Clarkcr wrote: Sorry if this is a hijack, but I'm trying to build gas tanks from 16 gauge stainless using a friend's Hobart EZ-TIG 165i and so far I'm not feeling the love. #10 cup, 3/32 red electrode, 1/16 308 filler and the electrode turns black almost immediately and a small bead of soot soon forms at the point.
- Otto Nobedder
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Agree with Werkspace.
Something is wrong in the gas coverage.
Steve S
Something is wrong in the gas coverage.
Steve S
It would help to know how much tungsten stick out as well. Sometimes you can detect a gas coverage issue by setting the tungsten shorter. Also, check the collet. If it has been over-tightened, it could be bent, twisted or expanded inside the collet body restricting gas flow. Also make sure it is actually a 3/32 collet or that all the parts match. I don't recall using a 3/32 tungsten on 16 gauge but it's been awhile.
You may also try welding a test piece in reverse travel. That way you are sure to have shielding directly on the puddle. If that helps, you may chalk it up to improper torch angle.
You may also try welding a test piece in reverse travel. That way you are sure to have shielding directly on the puddle. If that helps, you may chalk it up to improper torch angle.
Miller ABP 330, Syncrowave 250, Dynasty 300 DX.
Honorary member of the Fraternity of Faded Tee Shirts.
Honorary member of the Fraternity of Faded Tee Shirts.
I didn't read every word of the topic, too lazy 
To me it seems that you have a small leakage somewhere. Perhaps in the joint of hose or in the torch? Get a bottle of water/soap and check everything. Also it would be ideal to leave pressure overnight and check your regulator's reading in the morning.
Couple of questions more:
Have you cleaned your stainless well?
Have you tried to change gass bottle?
To me it seems that you have a small leakage somewhere. Perhaps in the joint of hose or in the torch? Get a bottle of water/soap and check everything. Also it would be ideal to leave pressure overnight and check your regulator's reading in the morning.
Couple of questions more:
Have you cleaned your stainless well?
Have you tried to change gass bottle?
-Markus-
Check to make sure you have gas flow out of the torch.... Last weekend I was practicing on some mild steel, and couldnt get a clean weld no matter what.
After an hour of frustration I went to increase gas flow. I stepped on my petal to get gas flowing so I could adjust it visually, and I got a short bump of the ball and then dropped back to zero... But when I let go of the petal I would see a second of flow...
Not real sure what the issue was, but I checked all the wires and hoses, and it started to work. The only thing I found that looked wrong was a slight kink in the hose leading to the torch. I didn't think it was bad enough to be a problem but who knows.
After an hour of frustration I went to increase gas flow. I stepped on my petal to get gas flowing so I could adjust it visually, and I got a short bump of the ball and then dropped back to zero... But when I let go of the petal I would see a second of flow...
Not real sure what the issue was, but I checked all the wires and hoses, and it started to work. The only thing I found that looked wrong was a slight kink in the hose leading to the torch. I didn't think it was bad enough to be a problem but who knows.
Samson el welder
- Samson el welder
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You need to purge to keep the pipe cooler just cause u weld cold doesn't mean the pipe is cool the cooler the weld the prettier also move quicker and weld without fillet just setup in a butt joint and make tight circles at about 45 amps with size twelve cup for more argon coverage and purge at about 25 cfh