Tig SS pipe Problem!

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Hello,On this new project I have been working on getting some .109wall 304SS tube welded up for a manifold.  I am getting full penetration but seem to be having a problem with the weld appearance and need some input.  I am using a syncrowave 200 for this project and have tried both 308 and 309 filler.  I have also adjusted the gas flow between 10-20 cfm and have a back purge setup at around 5cfm after flooding.  Also have tried both 1/16" and 3/32" tungstens and the same on filler.I have links below for the tube and two pictures of what the welds look like.Any guidance would be greatly appreciated.RobertTube infoPicture 1picture 2
Reply:might be too hot..
Reply:Your overheating the material, what amps are you running?  Regardless, you need to find a way to reduce your heat input.  Either less amps or faster travel speed.Have we all gone mad?
Reply:Opps forgot that part.  110 amp cap.  I tried several more things since my post and can not get it to look right.  I tried to v cut deeper and do a root pass at very low amps with no filler, but could not get penetration to the backside without using filler.  Using filler with just enough amps to melt the 1/16 rod into the puddle it would get that look the pictures show.  I also tried different speeds, but still no luck.  I'm pretty sure these are a cast tube.  Having never tig welded cast, could that be causing the look?Robert
Reply:Could the problem be related to the "Made in China" marking on the pipe?Rex
Reply:Are you running a gas lens in your torch?  If not, I would get one of those.  110 Amps should be alright for doing that, so its more likely your travel speed.  Another thing that might help is to try using the pulser to reduce your heat input.Have we all gone mad?
Reply:Way too hot. 65 to 75 amps. The dull appearance is from too much heat.UA Local 598
Reply:Originally Posted by WHughesWay too hot. 65 to 75 amps. The dull appearance is from too much heat.
Reply:I would think that you are moving to fast. And not cooling, or coming off the heat between beads. If you have backup gas, take your time relax. If you start the weld and create the first bead with no filler wire, you are at the right temperature. The trick is to move in very small increments. So small that you would think you won't get a stack of dimes. You heat, add wire, let the wire level out, come off the heat, wait till the puddle cools, and move just a tiny bit forward, and do that again and again. When you add filler wire, wait for a long time while applying heat until you see the puddle blend totally with the base metal. Then shut off the heat, wait till the puddle cools and move on. Much of our stainless is from China. Only the hydraulic grade seems to come from American companies. This is with no backup gas. I use a gas lens and a 1/16" tungsten.I let the tungsten stick out more then in the picture. That was just placed in there for the picture. If I had to do a bunch of these, I would use backup gas, probably use more heat for speed and slightly cleaner look.But I believe I did these to show that you can weld schedule 40 Stainless steel pipe with a small inverter welder. I kept my amps well under 90 amps. Probably around 70 amps.        Sincerely,             William McCormick
Reply:Incorrect torch angle & too slow? (The demo is 303.) Attached Images"SOUTHPAW" A wise person learns from another persons mistakes;A smart person learns from their own mistakes;But, a stupid person.............never learns.
Reply:yes lower the heat go slower and let argon do its work
Reply:Originally Posted by sn0border88If he wants to get full pen on 12ga tube, your going to want more than 65-75 amps.  I run that on 16ga tube and sometimes still want more.
Reply:Originally Posted by sn0border88If he wants to get full pen on 12ga tube, your going to want more than 65-75 amps.  I run that on 16ga tube and sometimes still want more.
Reply:Probably several things not quite right, two that jump out to me are arc length and from the area i circled in red (used the 2nd pic) torch angle If you lose the torch angle as you progress around the pipe the arc length increases. Longer arc length = more heat input but poorly focused i.e. it's wasted heat. Too long an arc length can also mess with quality of the gas shieldingIf the filler wire isn't kept within the gas shield then the end will oxidise and you dip oxidised wire into the pool. If the end of the wire is discoloured then that'll be adding to the problemsThe joint set up in the pics is going to need more amps than a set up that has a root gap and/or knife edged bevels which in turn will make it harder to avoid dull welds. All of these factors have an effect on amperage
Reply:Well we can just agree to disagree then, I believe those settings work great for you guys.  I ran a SS pipe the other day with an EB ring (3"XX heavy I think), 100-110 on the root pass and at least that on my fill passes.  No color on the backside (w/ purge of course), and no grey color on any spot during the fill passes.Have we all gone mad?
Reply:Thank you very much for all the input!  Looks like I will go buy a gas lens on Monday and work on some scrap material I have.  I will try a deeper bevel cut and do a root pass and layer on top of that.  I will probably cut that weld back out and replace the tubes so as not to have a problem.Thank you again.I will post up my results Monday night.Robert
Reply:sn0border88, Showdog75just curious if the amperage(s) you're each referring to was checked: while welding (?) with a clamp-on ammeter (????) or were these settings on two different brands and models  of power supplies?We have measured an older Lincoln 300/300 TIG set at 175 A welding consistently at 150 A and the newer Miller Dynasty 300 DX set for 175 welding at 175.00A.I'm not sure the settings of all power supplies are the weld power we've got at the torch, - all that matters is the bead and finished weld, (and the X-ray)?Apples and Oranges?rs_customs, your original welds look way too hot to me.Cheers,
Reply:I've also crept up to about 100 A on around 12ga and thicker SS.  the thing is we were moving, very high travel rate.  heat input is an exponential function of travel speed and only a linear function of Amperage.  If you travel faster at 110 A you'll put in a lot less energy than traveling slow at 60A.That being said most people are not comfortable OR not practiced enough to hit the very high travel rates, or the joint has bad enough mismatch that you're likely to blow through.   I used to run high amperage on my fill passes to lay them in fast and have it wet out.not for the beginner though, stainless doesn't need a lot of heat.Welding EngineerCertified Scrap Producer
Reply:I agree that if you get it right, you can turn up the heat, and move. Leaving a golden weld behind you. Usually though for someone not used to stainless steel, it is better for them to go a bit slower. From my own experience. Sometimes you get a bit more distortion, but I have found those welds to actually hold better then some of the colder welds done by better welders, or airline.  But if you practice on butt joints for a few days, practice sinking the puddle exactly, you will be able to just rip through those welds.        Sincerely,             William McCormick
Reply:Originally Posted by William McCormick Jr(snip)But if you practice on butt joints for a few days, practice sinking the puddle exactly, you will be able to just rip through those welds.        Sincerely,             William McCormick
Reply:Im using the same crappy china material for my exhaust parts im making as well. But just as everyone has said.-Use a gas lens. I use a gas lens on everything. And get the biggest cup you feel comfortable with as well.Here is a Tial wastegate flange Im welding on some schedule 10 pipe. FWIW I believe I welded this around 75 amps IIRC.-Back purging stainless is VERY important, you will notice a night and day difference if the way your welds look just by back purging.-Keep your torch angle more perpendicular to the base metal (this is where its tricky because you moving around a tight circle) to keep the sheilding gas flowing over the weld you just laid. And this also is where the gas lens and larger cup help as well.Last edited by SR20steve; 05-10-2010 at 11:43 PM.
Reply:Here are tonights pictures!  I put pulse to use on this and the new gas lens with a #7 nozzle.  Root settings no filler=90amps pps .5 (PT 40) (BK A 15).  Filler Pass settings = 110amps same pulse settings as root.I didn't have enough back purge on this particular weld so the inside doesn't look as nice as it should.I have a few more pictures if needed and there are two video links at the bottom of the post that show the tube being rotated to show the finished welds.Please let me know what you guys think.  I am a lot happier with the results and greatly appreciate the help!RobertRoot VideoFiller Video
Reply:The last ones looked much better. You are moving in too large an increment, or moving too much forward at each bead. Move half as much for each new bead. Don't be afraid to burn in stainless. Not burn the surface, but rather melt the bead more level. You will see that the weld edges blend with the metal tube. The heat will stay with you more if you totally properly heat the bead. The heat will actually leave the part behind the weld, and follow you. Rather then stay there and burn the surface. If you heat the part, start a bead with no filler, add filler, level out the filler. Chill the bead, move ahead just a bit, and do it all over again. You will get that amazing looking bead. And you will actually be moving faster, because of the heat and the way it follows and preheats for you. You will see that when your flow is more unpracticed and natural. That the heat stays with you, and you will find that you are welding probably faster then you are used to welding. Once you get that rhythm going. The heat stays just where you are welding.        Sincerely,             William McCormickLast edited by William McCormick Jr; 05-11-2010 at 12:27 AM.
Reply:Originally Posted by William McCormick JrThe last ones looked much better. You are moving in two large an increment, or moving to much forward at each bead. Move half as much for each new bead. Don't be afraid to burn in stainless. Not burn the surface, but rather melt the bead more level. You will see that the weld edges blend with the metal tube. The heat will stay with you more if you totally properly heat the bead. The heat will actually leave the part behind the weld, and follow you. Rather then stay there and burn the surface. If you heat the part, start a bead with no filler, add filler, level out the filler. Chill the bead, move ahead just a bit, and do it all over again. You will get that amazing looking bead. And you will actually be moving faster, because of the heat and the way it follows and preheats for you. You will see that when your flow is more unpracticed and natural. That the heat stays with you, and you will find that you are welding probably faster then you are used to welding. Once you get that rhythm going. The heat stays just where you are welding.        Sincerely,             William McCormick
Reply:Looks allot better, and you purged it this time? I know this is just practice but when you do a real joint you should take a drum flapper to the outside and inside to get good clean metal to weld to. And stuff that thin I don't think you should have to bevel it, but the slight bevel with a land wont hurt (and help be a guide as well).If it was me I wouldn't use any pulse, just use the pedal and just get in a nice smooth torch movement and get in a nice rthym of adding filler metal. As you go allong you will notice the puddle getting flatter but then you can just back off the pedal till you see the bead grow taller and narrower. The nice ripples will be from you adding filler. I seem to have the best appearance (this is subjective though) just tapping the filler in slightly but frequently.And remember to lower you amperage if you take it off of pulse.Last edited by SR20steve; 05-11-2010 at 12:27 AM.Originally Posted by SR20steveLooks allot better, and you purged it this time? I know this is just practice but when you do a real joint you should take a drum flapper to the outside and inside to get good clean metal to weld to. And stuff that thin I don't think you should have to bevel it, but the slight bevel with a land wont hurt (and help be a guide as well).If it was me I wouldn't use any pulse, just use the pedal and just get in a nice smooth torch movement and get in a nice rthym of adding filler metal. As you go allong you will notice the puddle getting flatter but then you can just back off the pedal till you see the bead grow taller and narrower. The nice ripples will be from you adding filler. I seem to have the best appearance (this is subjective though) just tapping the filler in slightly but frequently.
Reply:Pulse it yourself, or just cool each bead yourself, if you can. That is usually the best for looks. Because instead of the puddle being able to walk. Away from the cold new metal and to the side. You are going to move the torch over to the exact spot you want to start heating. You do not have to solidify the puddle totally. But definitely come off the heat, at least shrink the puddle, them move on. That is what is so nice about TIG, you are in total control. No real rush really. You have to kind of setup an imaginary stop for your high heat and your low heat in your mind. And just keep doing that with the pedal. After a while you do not even think about it. Like driving a car. You do not even think about gas and brake like when you first drove. It can be hard to get the rhythm down. Because you probably have about a million things on your mind. And that is good. Because that is what makes you really good. You start to handle all those things a lot faster, and faster. Truth be known my father stood behind me. And grabbed my hand with his crab claw grip, and got me back into the proper rhythm about twenty times. Before I gave up on any hope of myself developing my own rhythm or style. Ha-ha. He would pull the torch a half inch off the work, exaggerating the moving ahead procedure and timing, and it would still look nicer then my methods. It was just demoralizing. Ha-ha. "More pedal, come off the heat". For days. But I will tell you it sunk in well. My father probably taught a couple hundred welders to weld at Grumman. So there was no chance at free lancing. At one time I believe he had well over 100 certifications. So I just had to stand there and take it.The stack of dimes is more then just a look. It is a method. When you move in smaller increments, and cool between beads, you create many layers of weld. Almost like plywood compared to solid wood. Each time you cool a bead, it surfaces contaminants. That will not stay in the weld all the way through. It will leave them there. The next new bead washes up like waves on a beach on the old bead. And the contaminants are left behind there.        Sincerely,             William McCormick
Reply:I can't share a pic from my work, but I'm currently doing a 1/8" thick square butt, single pass, pulsed GTAW on a 2-3/4" diameter, 347 SS cylinder.  The weld is automated and inside a helium filled chamber.  The joint is difficult to penetrate because of the thickness and the low sulfure material chemistry.  Amperage is pulsed from 85 to 45 amps with a frequency of 0.75 Hz and duty cycle of 50% high time/low time, travel speed is 3 inches per minute, wire feed is sync pulsed with the current from 20 to 10 inches per minute, and the arc gap is maintained at 0.040" via the automatic voltage control setting of 15 volts.  Helium has a huge effect on inproving heat transfer over argon since it's thermal conductivity is about 9X greater.  With argon, the amperage would have to much higher.The material chemisty has a huge effect on GTAW penetration, google Marangoni fluid flow, heat-to-heat variation, or thermocapillarity.  In very general rough terms, low sulfur material, below about 60 ppm (0.006 wt%), can be very difficult to penetrate because the fluid flow in the weld is outward from the center, making the weld wide and shallow as heat input is increased.  Higher sulfur material is the opposite, inward flow, making a narrow deep weld.  You cannot just look at the ASTM chemistry range for SS, you need the actual chemistry analysis for the heat of steel you are working with.  Here is a link to a penetration enhancing flux.  http://www.ewi.org/NJC/resources_detail.asp?ID=36
Reply:Originally Posted by pulserI can't share a pic from my work, but I'm currently doing a 1/8" thick square butt, single pass, pulsed GTAW on a 2-3/4" diameter, 347 SS cylinder.  The weld is automated and inside a helium filled chamber.  The joint is difficult to penetrate because of the thickness and the low sulfure material chemistry.  Amperage is pulsed from 85 to 45 amps with a frequency of 0.75 Hz and duty cycle of 50% high time/low time, travel speed is 3 inches per minute, wire feed is sync pulsed with the current from 20 to 10 inches per minute, and the arc gap is maintained at 0.040" via the automatic voltage control setting of 15 volts.  Helium has a huge effect on inproving heat transfer over argon since it's thermal conductivity is about 9X greater.  With argon, the amperage would have to much higher.The material chemisty has a huge effect on GTAW penetration, google Marangoni fluid flow, heat-to-heat variation, or thermocapillarity.  In very general rough terms, low sulfur material, below about 60 ppm (0.006 wt%), can be very difficult to penetrate because the fluid flow in the weld is outward from the center, making the weld wide and shallow as heat input is increased.  Higher sulfur material is the opposite, inward flow, making a narrow deep weld.  You cannot just look at the ASTM chemistry range for SS, you need the actual chemistry analysis for the heat of steel you are working with.  Here is a link to a penetration enhancing flux.  http://www.ewi.org/NJC/resources_detail.asp?ID=36
Reply:Originally Posted by Showdog75Come on dude this is a beginner. Talk about sensory overload for the poor guy.He needs the basics.
Reply:Might not should have labeled you a beginner but somene that needs basic tig info not a bunch of metalurgical mambo jambo. That'll come later.
Reply:Originally Posted by Showdog75Might not should have labeled you a beginner but somene that needs basic tig info not a bunch of metalurgical mambo jambo. That'll come later.
Reply:One thing that I think you might benefit from is changing your pulse settings a little bit.  You have the machine there to do it so no reason to bother with pulsing with your foot or moving the torch around like a fool.Your PPS is fairly low, the lower the PPS the longer your peak time is.  I would suggest changing the PPS to around 2 and turning your amps up to ~150.  You could also try turning your peak time down a little bit depending on how hot its getting but I think it will be ok there.With those settings your going to get deep penetration because of the high amperage but the low background and short peak time gives the pool time to cool and prevents the puddle from getting very large.I typically run 2.5-3PPS, 30 Peak 10-20 Background and 150 amps on sanitary lines (2-3" .065 304) when im working in position.  You really have to fly around the pipe but it has very low heat input and still gets full penetration with no filler or edge prep.Have we all gone mad?
Reply:Originally Posted by pulserThe material chemisty has a huge effect on GTAW penetration, google Marangoni fluid flow, heat-to-heat variation, or thermocapillarity.  In very general rough terms, low sulfur material, below about 60 ppm (0.006 wt%), can be very difficult to penetrate because the fluid flow in the weld is outward from the center, making the weld wide and shallow as heat input is increased.  Higher sulfur material is the opposite, inward flow, making a narrow deep weld.  You cannot just look at the ASTM chemistry range for SS, you need the actual chemistry analysis for the heat of steel you are working with.
Reply:I will add that Sn0 must have a different machine than most.We've had this discussion before about his amp/pulse settings.  I've never had any luck with his settings on either my Sync 250 or my Dynasty 200.  When I tried his settings (didn't agree with them to begin with) all I did was blow holes in thin wall SS tubing.Sn0.  Did you ever get your hands on a Dynasty so you could try the hi-speed pulsing?Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIII will add that Sn0 must have a different machine than most.We've had this discussion before about his amp/pulse settings.  I've never had any luck with his settings on either my Sync 250 or my Dynasty 200.  When I tried his settings (didn't agree with them to begin with) all I did was blow holes in thin wall SS tubing.Sn0.  Did you ever get your hands on a Dynasty so you could try the hi-speed pulsing?
Reply:Originally Posted by Showdog75Come on dude this is a beginner. Talk about sensory overload for the poor guy.He needs the basics.
Reply:I have found that on stainless steel, usually slower is stronger.        Sincerely,             William McCormick
Reply:Yes, because going slow and increasing your heat input is a good thing on stainless.  Dont worry about that carbide precipitation nonsense.  What testing did you do to prove that slower is stonger? UT?  Bend test?  BFH?Sundown, We did get a dynasty 200 in our shop now and I have tried many different settings with it.  I do think the high freq pulse in some scenarios, but for most tube work I stick with my old settings.What would you reccomend as far as pulse settings to get good results on .065 tube?  Also, could you shed some light as to how the background and peak time effect the weld once you get above 100PPS, or do they have similar effects when welding at 2PPS?Oh, and the only machines im using is a sync 250 and the dynasty.  Ill weld out a sample piece sometime to prove that im not crazy, or full of chit.Have we all gone mad?
Reply:Was tight for time and swung by to got one pass done.  I think if I would have beveled the edges and moved faster this might have worked out.  It looks like it was on the edge of having too much heat in it when it left the gas shielding.I know you used them for a smaller thickness, but figured I'd give it a shot without beveling on the thicker stuff.  150amps, pps 2, 30 main, 15 back.Robert
Reply:Yup that got too hot, what kind of motion were you using?  It just seems like the bead is very wide and the ripples look odd, I always run this stuff nice and straight.  One thing that I find works well (again, this is on thinner stuff)  is I start the puddle off nice and slow and wait until I see the little white spec start to spin around in the pool. Once its moving nice and good I start to move, keeping an eye on it to make sure its still there.Generally, as long as you can see that white spec spinning your getting full penetration.Have we all gone mad?
Reply:I wasn't wandering side to side, just straight for the most part.  I had the pedal floored just to see if I could get the full penetration.  I figured if I was able to I could work on backing off the heat, but since I didn't I will try beveling and lower heat tomorrow.What white spec are you talking about?  Just the center of the wandering arc pool?Robert Originally Posted by sn0border88Yup that got too hot, what kind of motion were you using?  It just seems like the bead is very wide and the ripples look odd, I always run this stuff nice and straight.  One thing that I find works well (again, this is on thinner stuff)  is I start the puddle off nice and slow and wait until I see the little white spec start to spin around in the pool. Once its moving nice and good I start to move, keeping an eye on it to make sure its still there.Generally, as long as you can see that white spec spinning your getting full penetration.
Reply:Hard to explain really, more of a "I need to show you" thing.Now granted this is through my gold shaded lens, but somewhere in the pool usually towards you can see a little white spec form.  Some people call it a jitterbug, cause it just swirls around at random.  You will also see this on carbon steel and is very helpful when running TIG open roots.  As long as that spec is doing its thing you can be pretty confident your getting a good tie in on the inside of the root.Have we all gone mad?
Reply:That is not terrible. The color if you really need it to look shinny you can get a larger cup. That is what they do for some defense plant type of welds. They use a giant cup. Almost two inches across. With a tiny 1/16" inch tungsten. Then your bead would look sick. They just adapt a cup made for really large tungsten to a 1/16" tungsten. They call it a trailing cup. You are wandering a little, and not consistent. But other then that, the weld is probably very strong. What they did for pipe applications because not to many on the job, in the field, while out of position can do that in one pass. They let you do a root and a cover. It is not the best or the worst. But the odds favor it in the field.When a perfect weld goes bad we often do a cover pass and no one knows. Ha-ha.        Sincerely,             William McCormick
Reply:Been a while since this project, but wanted to post up and say thank you again to everyone that helped me figure it out.  I won't say it's great but I think it turned out ok.Here are a couple pictures. Thanks again.Robert
Reply:Originally Posted by rs_customsBeen a while since this project, but wanted to post up and say thank you again to everyone that helped me figure it out.  I won't say it's great but I think it turned out ok.Here are a couple pictures. Thanks again.Robert
Reply:[QUOTE=rs_customs;441928]Been a while since this project, but wanted to post up and say thank you again to everyone that helped me figure it out.  I won't say it's great but I think it turned out ok.I'll say it looks great to me.  Looks like something you'd pay someone else a lot of money for.  I'd be proud of that if I did it for sure."The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25
Reply:Originally Posted by SR20steve  I seem to have the best appearance (this is subjective though) just tapping the filler in slightly but frequently..
Reply:Thanks for the comments guys!4sfed  I'll have to ask my buddy what he had applied.  He had a local guys do it here in town and the first coating flaked off after the first time running the car.  The second coating seems to be holding up to 2000 degree f using pyrometers in the manifold to know what it seeing (rotarys get hot, lol).I'll find out and let you know.Robert
Reply:New guy here.   Have been lurking around the site for a while now, and saw this thread because I need some of the exact same help here.Tips that were thrown out here are great so far, and I am getting cleaner SS welds now, but not perfect yet.  All the how to's and you tube videos, I see people laying long single pass beads of SS welds with a standard cup and no back purging without any oxidation and the welds look like sex.  I just don’t get it. my setup is as follows for some 16ga 304 exhaust tubing and some 1/8th scrap plate for straight beads no fitments:Thermal Arc - Arcmaster 185#7 gas lenses, 1/16th 1.5% Lanth, sharp long point, ave of 14cfh (tried higher and lower), 309L 1/16th filler, 100% argonDC pulsed, 60 amps, 6amps background, 40% peak time, 10hzI cant seem to get the beads to stay shiny.  They are grayish.  Not super grey but nowhere near shiny.  the bead profile is very nice, semi flat and the HAZ isnt giant imo, maybe 1/2" from edge to edge.  If I lay a long bead on some flat sheet about 3 - 4 inches long only the last 3/4" or so is clean like I want it to be.  post flow is 10 seconds.  Its almost like I am out running my gas shield.  So I try 1 inch or less starts and stops, waiting to cool.  As soon as I start up the next batch of welds, about half of the prior welds turn grey.  If i turn down the amps to around 40 or so, I cant even get a puddle to form and flatten out, so I sit there working it longer, and feel like I am putting more heat into the metal while doing so.  Torch angle is close to 90 deg.  so the argon hits the weld and moves forward ahead of my weld and trails behind a little helping it cool.  Interestingly I found that I got slightly shinier trailing welds if I held the torch at a wicked forward facing angle.  no idea why... seem like it should be the opposite result.I will go home and mess around on some scrap and post some pics tomorrow.