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I have been practicing stick pipe welding and I have a couple questions to try to solve some problems I'm having.I have pipe that is about 2 1/2" diameter and roughly 3/16" wall thickness. On the root pass the problem I keep getting is the keyhole blowing open near the top. I originally was using a 1/8" 6010 on a 1/8" gap and land at about 70-80 amps but switched to 3/32" 6010 with 3/32" gap and land at about 55-60 amps in an attempt to have more control over the heat. How do I keep the keyhole under control? Am I way too hot? UA specs for 6G test are 75 minimum for 1/8" so shouldn't I be able to run it at that at least, or is it different since I am not on thicker 6" pipe? Is my gap / land wrong?the root I do get in has penetration through, but the reinforcement doesn't seem to be quite as much as can be seen in videos like fieldres or jody. It seems to be flush or just very slightly above and not as consistently the same throughout as those guys. How deep should the rod be in the gap? should the end of the rod be slightly above where the land is, equal with the land, or past the land inside the pipe?Once the root pass is in, I don't understand how I could get 3+ passes in. After the root, I'm just under flush so I can only see room for a cap. Is it because of the wall size of the pipe? Or is it because of my next question: What is the proper way to bevel the pipe? If the pipe is in the 5g position and I am using a angle indicator should it be 30 degrees ( a very wide bevel) or should it be 60 degrees ( a pretty steep bevel)? I know on plate a 22.5 degree bevel would be measured as 67.5 so is it the same with pipe? On a cap pass, I've only tried 1/8" 7018 as its all I have right now. I usually run it around 100-110 amps and every time the bottom is going in just fine but once I start getting vertical the puddle begins to quiver a bit and then everything just drips out and I begin to form a hole straight through the pipe. How do I solve this?Lastly, what should my angle of my rod relative to the pipe be when I am welding? Should I always try to be 90 degrees from it, straight in? or should I have a slight angle like this / around the pipe?
Reply:i think you could gain a lil more build up on inside of root if you tighten your gap up, and turn the heat up a lil if need be. i'd try to stick w/ 1/8 6010, but drop to 3/32 on the 7018 for 2.5 pipe
Reply:Get heavier pipe 3/16 wall isn't what your test will be on. You are wasting your time. You are blowing out your root because the wall thickness is so thin the pipe cant handle the heat. With this pipe you will have to constantly stop to let the pipe cool while running your root. Can you root 2 1/2 inch 3/16 wall pipe with stick ? Yup with patients and letting the pipe cool down once it starts to heat up Id be running 3/32 (6010/7018) as well. Watch your key hole, if it starts to open up just break the arc, and let the pipe cool for a few minutes before starting back at it.I like to have my rod pointed straight into the pipe. Generally pipe is 37.5 degrees and plate is 30. Typically pipe fittings come pre bevelled 30 degrees so that's what I usually go with. I like to drag my roots in if I can, I try to only whip when the key hole opens up.The main thing, get heavier pipe !!!! You cant practice proper fill and cap passes on that wall pipe. Most tests I have taken have been on XX strong 2 inch.Last edited by Newfie_1986; 02-13-2016 at 10:23 PM.Journeyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:Isnt the UA test, 6-inch sch 80 pipe? Also arent you allowed a 1/16-inch gap, minimum? For what little pipe welding Ive done. I like 30-degree bevel. 3/32-inch land. For small pipe Ill use a 5/64-inch drill bit to set the gap. Small pipe will close the gap more so than bigger pipe. For bigger pipe I use a 3/32-inch drill bit to set the gap. I use 1/8-inch 6010 run at least 75-amps.When the gap closes up on me I point the rod forward, to help cut the gap open.If the gap opens up on me, I point the rod back, on already deposited weld. Attached ImagesDont pay any attention to meIm just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:As for the heat settings, ALL machines are different on the number settings. Some seem hotter others too cold . Adjust heat to your liking for control. As for standard 2 1/2'' schedule 40 pipe, we only two pass it. You could do three but that is easier when you grind the root. As for testing, besides Union certification and testing, most jobs had their own test required. Most were all 2 1/2'' and 6'' schedule 80.
Reply:Some other posters have already touched on these things, but I'd like to reiterate them for emphasis:2 1/2" SCH 40 is a terrible heat sink. It's going to get very hot, very fast. As you know, heat rises, so it's all there waiting for you at the top. That's what's causing you to lose your keyhole.ASME B31.3 (the uphill pipe welding code) specifies that the root reinforcement can be flush to 1/16" reinforcement. As long as it's at least flush, you're good.The proper way to bevel pipe is dependent on the code you're welding to. ASME B31.3 dictates a 37.5 degree bevel, while API 1104 (downhill procedure) specifies a 30 degree bevel angle. Those would present a 75 and 60 degree included angle, respectively.Running a cap pass on that small bore pipe with an 1/8" rod is going to be very frustrating. Even if you start with a cold pipe, it's going to heat up so fast that the bead is going to go to ****. Use 3/32".Somebody mentioned dragging a root as opposed to whipping it. That will be dependent on the applicable code. API 1104 is a downhill drag root, ASME B31.3 is an uphill whip and stitch root.Regarding angles for putting in the root pass. There is not set answer. This isn't structural welding, pipe welders are supposed to be a cut above. You need to be able to read the puddle. Your work angle should start out at zero, but you will have to tilt it one way or the other towards one side if the weld isn't going in evenly. If you don't, you'll find a lack of penetration and probably an exposed bevel edge on the inside, which is a rejectable defect. Same deal with the travel angle. Push, drag, or straight on will depend on the penetration you're getting. If the keyhole is opening up too wide, then push the electrode away from the puddle to keep the heat of the arc away from it to close it faster. If it's not opening up enough, then angle it back into the puddle to really lay the heat into your lands and get it to penetrate completely. Hope this helps.
Reply:Umm yeah that was me who mentioned a drag root. You can drag a root up hill no API 1104 around here. No cross country pipe lines in Newfoundland. Everything here is ASME and I drag my roots up. For the most part unless the fit is bad in places. Originally Posted by Hillbilly WelderSome other posters have already touched on these things, but I'd like to reiterate them for emphasis:2 1/2" SCH 40 is a terrible heat sink. It's going to get very hot, very fast. As you know, heat rises, so it's all there waiting for you at the top. That's what's causing you to lose your keyhole.ASME B31.3 (the uphill pipe welding code) specifies that the root reinforcement can be flush to 1/16" reinforcement. As long as it's at least flush, you're good.The proper way to bevel pipe is dependent on the code you're welding to. ASME B31.3 dictates a 37.5 degree bevel, while API 1104 (downhill procedure) specifies a 30 degree bevel angle. Those would present a 75 and 60 degree included angle, respectively.Running a cap pass on that small bore pipe with an 1/8" rod is going to be very frustrating. Even if you start with a cold pipe, it's going to heat up so fast that the bead is going to go to ****. Use 3/32".Somebody mentioned dragging a root as opposed to whipping it. That will be dependent on the applicable code. API 1104 is a downhill drag root, ASME B31.3 is an uphill whip and stitch root.Regarding angles for putting in the root pass. There is not set answer. This isn't structural welding, pipe welders are supposed to be a cut above. You need to be able to read the puddle. Your work angle should start out at zero, but you will have to tilt it one way or the other towards one side if the weld isn't going in evenly. If you don't, you'll find a lack of penetration and probably an exposed bevel edge on the inside, which is a rejectable defect. Same deal with the travel angle. Push, drag, or straight on will depend on the penetration you're getting. If the keyhole is opening up too wide, then push the electrode away from the puddle to keep the heat of the arc away from it to close it faster. If it's not opening up enough, then angle it back into the puddle to really lay the heat into your lands and get it to penetrate completely. Hope this helps.
Reply:Well I don't know how things work in Canada, but in the United States you're required to abide by the WPS and the procedures set forth by the applicable code. A drag root is not part of the ASME procedure. Originally Posted by Newfie_1986Umm yeah that was me who mentioned a drag root. You can drag a root up hill no API 1104 around here. No cross country pipe lines in Newfoundland. Everything here is ASME and I drag my roots up. For the most part unless the fit is bad in places.
Reply:ASME only dictates what direction you weld not preference for whip and pause or dragging your root from bottem to top. Dragging your root from bottem to top is perfectly fine with ASME. Done it on plenty of tests at the hall.And yeah we weld pressure to ASME codes in Canada.Journeyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:The problem with dragging a root is that tends to result in a smaller bead with less "meat" than a whip and stitch technique. This isn't good, because when it comes to pressure piping and vessels, you want the root to be as beefy as possible. Certainly not saying it can't be done, just that the whip and stitch method puts in a better root for pressure piping. Originally Posted by Newfie_1986ASME only dictates what direction you weld not preference for whip and pause or dragging your root from bottem to top. Dragging your root from bottem to top is perfectly fine with ASME. Done it on plenty of tests at the hall.And yeah we weld pressure to ASME codes in Canada.
Reply:I have never had an issue with dragging a root, and getting buildup inside. If you read Hoobasar Rampauls book on pipe he actually recommends dragging the root in on the botten, it helps with penetration. Once you go up the sides he says to whip to help avoid wagon tracks, on your bead in the bevel. The meat is all dependant on pressure on the rod. I can have flush, just above flush or even up to 1/8". And as far as "meat" inside the pipe is concerned, some inspectors are fine with flush others want 1/16". Haven't seen any inspector want 1/8".In my 8 years welding I have learned just because a technique doesn't work for one doesn't mean it doesn't work. I recall back when learning to weld, I was told to watch as many techniques as possible and pretty much try them all and see what worked for me. Sometimes one technique worked and other times I used a combination of others techniques but got the same results. I do whip my roots if the fit up gets wide or it starts to keyhole much, but otherwise I and I will say that again "I" find it much faster and easier to drag it up. I'm a UA member UA 740 and guys at our hall all weld somewhat differently. Different fit ups and techniques. Its a do what works trade. Originally Posted by Hillbilly WelderThe problem with dragging a root is that tends to result in a smaller bead with less "meat" than a whip and stitch technique. This isn't good, because when it comes to pressure piping and vessels, you want the root to be as beefy as possible. Certainly not saying it can't be done, just that the whip and stitch method puts in a better root for pressure piping.
Reply:I'm actually quite familiar with Mr. Rampaul's book, it's an excellent source of information for pipe welders. I'm not trying to say that dragging a root will always cause problems, simply that it's more prone to them. You'll never find an inspector that wants 1/8" reinforcement on an uphill root, because ASME limits are 0-1/16". One problem that occurs often with inexperienced pipe welders is "suck back" on the bottom of the root, because they're simply going too fast. A drag root is a very fast technique, that's why it's used in the API 1104 procedure. You have to force yourself to slow way down in order to ensure adequate penetration and reinforcement. That's why the whip and stitch root is used most often, other than on the bottom as you said, because by its nature it is a slower technique that lends itself well to ensuring a high quality bead is placed.I agree it's a "do what works" trade, I'm not at all trying to say that dragging an uphill root doesn't work. Originally Posted by Newfie_1986I have never had an issue with dragging a root, and getting buildup inside. If you read Hoobasar Rampauls book on pipe he actually recommends dragging the root in on the botten, it helps with penetration. Once you go up the sides he says to whip to help avoid wagon tracks, on your bead in the bevel. The meat is all dependant on pressure on the rod. I can have flush, just above flush or even up to 1/8". And as far as "meat" inside the pipe is concerned, some inspectors are fine with flush others want 1/16". Haven't seen any inspector want 1/8".In my 8 years welding I have learned just because a technique doesn't work for one doesn't mean it doesn't work. I recall back when learning to weld, I was told to watch as many techniques as possible and pretty much try them all and see what worked for me. Sometimes one technique worked and other times I used a combination of others techniques but got the same results. I do whip my roots if the fit up gets wide or it starts to keyhole much, but otherwise I and I will say that again "I" find it much faster and easier to drag it up. I'm a UA member UA 740 and guys at our hall all weld somewhat differently. Different fit ups and techniques. Its a do what works trade.
Reply:Im not going to argue but you started out saying a drag root isn't even allowed by ASME !!! Now its just prone to more issues. (Your opinion, not mine) You may have more issues with it but others may not.Anyhow as for suck back, myself I find I'm much more likely to get suck back on bottom than up the sides or on the top. Which is why I drag. Anywhere else on the pipe gravity helps. Gravity is the biggest hurdle to overcome with suck back. In most cases if anyone has suck back its on the bottom. Unless its stainless and their purge is blowing out the root. I find if I whip the bottom I go too slow causing suck back, going too slow causes more heat input into the pipe thus causing suck back. Same as a tig root, go too slow on bottom and you get suck back. Lets just agree that its best to offer a newbie starting out a bunch of different techniques and let them find what works. Rather than trying to state one is wrong over the other. Originally Posted by Hillbilly WelderWell I don't know how things work in Canada, but in the United States you're required to abide by the WPS and the procedures set forth by the applicable code. A drag root is not part of the ASME procedure.
Reply:I believe the part you're referring to is when I said "Somebody mentioned dragging a root as opposed to whipping it. That will be dependent on the applicable code. API 1104 is a downhill drag root, ASME B31.3 is an uphill whip and stitch root." This wasn't intended to say that a given code prohibits one technique over another, but when I think of drag roots I think of API 1104 and running downhill, and when I think of whip and stitch roots I think of ASME B31.3 and running uphill.I concur, providing new welders with different techniques to try is the best approach, so as to allow them to figure out what works best for them. Originally Posted by Newfie_1986Im not going to argue but you started out saying a drag root isn't even allowed by ASME !!! Now its just prone to more issues. (Your opinion, not mine) You may have more issues with it but others may not.Anyhow as for suck back, myself I find I'm much more likely to get suck back on bottom than up the sides or on the top. Which is why I drag. Anywhere else on the pipe gravity helps. Gravity is the biggest hurdle to overcome with suck back. In most cases if anyone has suck back its on the bottom. Unless its stainless and their purge is blowing out the root. I find if I whip the bottom I go too slow causing suck back, going too slow causes more heat input into the pipe thus causing suck back. Same as a tig root, go too slow on bottom and you get suck back. Lets just agree that its best to offer a newbie starting out a bunch of different techniques and let them find what works. Rather than trying to state one is wrong over the other.
Reply:how is a drag root vs whip root done? Would you be hotter dragging, or have a closer gap? Or can both be used with the same settings?Also, what are the best ways to get bigger pipe? Even buying it, where do you find 6" pipe?Last edited by LeviC; 02-14-2016 at 05:22 PM.
Reply:When I'm welding a downhill pipe joint, I like to run about a 1/16" gap and 3/32" land. The downhill procedure using a drag root is much faster than going uphill with a whip and stitch, and thus the arc has less time to penetrate the bevel edges so that the puddle can fuse properly. You're also welding into cold metal with a downhill root (because heat rises) so you don't need as much of a heat sink. When I'm welding an uphill root, I like a heavy landing (1/8") and a 1/8" gap as well. Welding an uphill root with a whip and stitch procedure is slower and deposits more metal, which both equate to more heat input. As such, you need heavier landings to be able to absorb that heat, otherwise you're just going to blow a hole in it. Regarding the machine settings, I run them about the same. I like my root to go in right around 83 amps, assuming proper fitup. If you have tight spots or excessive gaps in places, then you'll have to adjust your machine accordingly, until you become proficient enough to counteract the poor fitup with the manipulation of your rod. It takes time to learn.Ways to get pipe, your easiest option is obviously to go to a steel yard and buy it. It's not cheap though. Around here, if you want 8" SCH 40, you're gonna pay about $60/ft if I remember correctly. It's not cheap.
Reply:Scrap yards, pipe warehouses, steel supply yards, larger plumbing companies ........If your sticking to Lowes or Home Depot or something like that you'll never find it......
Reply:If you look back at post 13 you will see the post I quoted where you said "A drag root is not part of the ASME procedure." This could lead to some confusion for a newbie making them think they are not allowed to drag uphill. Sometimes with the internet and the written word it is hard to get your point across. Back when I started welding and I was on here getting advice I was confused as hell. People telling me to do things one way or another and, that what this one or that one said wont work.As for a drag root. Last job I was on we were welding 3 " sch 80. Id run a 3/32 land/gap, the dig on the maxstar was at 100% (garbage welder for stick pipe)and id set my heat just hot enough so a small keyhole would follow behind me, its sort of under the tip of the rod and hard to see. I would have more pressure on the rod on bottom than on the sides or top. The top kind of just falls in for you. Where ever a keyhole would open up (wider gaps) Id whip. You will not always have a perfect fit out in the field. I like a high dig/arc force setting while rooting. If the pipe closes up I can just shove harder, which with a high dig setting increases amperage and that will keep pushing the root in.As for your search for pipe. Myself I usually get used pipe if I can for practice, I practice at home and the hall. But home I use used, because im cheap. Rust doesn't matter because you will be cleaning the inside and bevelling/cleaning the outside anyhow. Myself I have 5" sch 80 at home. I got it cheap so couldn't complain (cant remember what I paid sorry). With that in mind 6 inch would be better, but as I said I got it cheap and im cheap as well hahahaWhen you get a 6010 root down you should work on a 7018 root depending on where you are located. Some refineries in the gulf I hear require it. And yes some procedures call for a 7018 root (its done at our refinery here). 1/8 land/gap with a 3/32 7018 is the set up I use for that. If you can root with 7018 you will be able to root with just about any rod. Originally Posted by Hillbilly WelderI believe the part you're referring to is when I said "Somebody mentioned dragging a root as opposed to whipping it. That will be dependent on the applicable code. API 1104 is a downhill drag root, ASME B31.3 is an uphill whip and stitch root." This wasn't intended to say that a given code prohibits one technique over another, but when I think of drag roots I think of API 1104 and running downhill, and when I think of whip and stitch roots I think of ASME B31.3 and running uphill.I concur, providing new welders with different techniques to try is the best approach, so as to allow them to figure out what works best for them.
Reply:Originally Posted by Newfie_1986Get heavier pipe 3/16 wall isn't what your test will be on. You are wasting your time. You are blowing out your root because the wall thickness is so thin the pipe cant handle the heat. With this pipe you will have to constantly stop to let the pipe cool while running your root. Can you root 2 1/2 inch 3/16 wall pipe with stick ? Yup with patients and letting the pipe cool down once it starts to heat up Id be running 3/32 (6010/7018) as well. Watch your key hole, if it starts to open up just break the arc, and let the pipe cool for a few minutes before starting back at it.I like to have my rod pointed straight into the pipe. Generally pipe is 37.5 degrees and plate is 30. Typically pipe fittings come pre bevelled 30 degrees so that's what I usually go with. I like to drag my roots in if I can, I try to only whip when the key hole opens up.The main thing, get heavier pipe !!!! You cant practice proper fill and cap passes on that wall pipe. Most tests I have taken have been on XX strong 2 inch.
Reply:Find a pipe fab shop nearby and ask them if you can dig thru their scrap dumpster. You might get lucky. 2 inch schedule 40 with stick is pretty tough. 1/8th 7018 is way too big for that.
Reply:I really don't see how you could even specify "drag" or "whip" root. The distance you whip away can't even be specified, and it changes based on the position and heat build up. Standard practice for whipping it actually starts out as a drag on the bottom, baby stepping into the whip into the vertical, and then stepping out the whip further at the top. It seems pretty assinine to try to say it HAS to be whipped when there isn't even a specification for the size or duration of the whip.
Reply:If it's getting too hot by the time you get to the top, you can try welding the top quarter first, then drop down to the bottom. I always do that when I have to weld something in position, it cuts down on the amount of upward draw.As for the drag/whip thing; you can do it either way, your preference. |
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发表于 2021-8-31 22:14:13