Welding Pieces Together To Make A Solid Piece

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Let's say you have a bunch of 2 foot pieces of say square tubing or angle iron, can you weld 5 of them together to make it 10 feet and it be as strong as a 10 foot piece from the mill? The way I was thinking of doing it is by beveling it at an angle on both pieces and making the weld a little higher than the base metal. If you grind it down to smooth it, would it make it weak or is it okay?
Reply:Originally Posted by TVGuideLet's say you have a bunch of 2 foot pieces of say square tubing or angle iron, can you weld 5 of them together to make it 10 feet and it be as strong as a 10 foot piece from the mill? The way I was thinking of doing it is by beveling it at an angle on both pieces and making the weld a little higher than the base metal. If you grind it down to smooth it, would it make it weak or is it okay?
Reply:If you put a bunch of clamps on it it should stay real straight. It will only be just as strong as factory if you weld it good and right tho. You could weld a 3/8 coupon and send it to me and I'll bend it to see how it does. Then you will know if it will be strong or not . What thickness is it?Last edited by motolife313; 03-01-2015 at 07:00 PM.
Reply:Certainly not an engineer, nor a weldor but I relate it to lumber.Years ago nearly all wood you found in a lumber yard was a single piece as opposed to today when you can find laminated beams (as example) as well as longer pieces of trim that are finger jointed butt end to butt end so as to make a longer piece of wood.In the case of wood, the orientation of the pieces plays a large role in the finished pieces use.  Laminated beams work, at least in part, because of the way the fibers are oriented to one another.  In the case of the finger jointed pieces forming a much longer piece, they are most often restricted to trim as opposed to structural use.  (AFAIK the glue joint is stronger than the wood fiber)As I first stated I am not an engineer and the welding process MAY allow it to make one longer piece out of smaller pieces.  Still not sure I would want to use a bunch of short pieces welded end to end to make up a structural unit.  I know what the theory is, just not sure I can convince myself it is applicable across all situations.Edit: thinking about this a little more, how are "I" beams made?  Could you weld up an "I" beam that would pass control/tests out of long runs of flat stock (of appropriate size)? Edit II: to answer my own question, "plate girders", overview was interesting but WAY WAY to much math (8 pages of symbol explanations alone).  I had assumed nearly all I beams were extruded/formed  Similarly, could you take short drops of roll cage tubing, weld the ends together to form a much longer piece and use that piece as part of a certified cage?Last edited by RussZHC; 03-01-2015 at 07:44 PM.
Reply:Originally Posted by motolife313If you put a bunch of clamps on it it should stay real straight. It will only be just as strong as factory if you weld it good and right tho. You could weld a 3/8 coupon and send it to me and I'll bend it to see how it does. Then you will know if it will be strong or not . What thickness is it?
Reply:that was the first one to break it in. She's good now!
Reply:Originally Posted by RussZHCCertainly not an engineer, nor a weldor but I relate it to lumber.Years ago nearly all wood you found in a lumber yard was a single piece as opposed to today when you can find laminated beams (as example) as well as longer pieces of trim that are finger jointed butt end to butt end so as to make a longer piece of wood.In the case of wood, the orientation of the pieces plays a large role in the finished pieces use.  Laminated beams work, at least in part, because of the way the fibers are oriented to one another.  In the case of the finger jointed pieces forming a much longer piece, they are most often restricted to trim as opposed to structural use.  (AFAIK the glue joint is stronger than the wood fiber)
Reply:I have been told by two former employees of steel mills that very large I beams are made from standard lengths welded together. I can't say I've ever seen one I thought was an example. I have to think the stresses found when part of a member cools from a molten state would affect strength. Maybe in a well equipped facility where it could go into an oven and be normalized.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:Thanks drooopy, have to go looking having never seen finger jointed dimensional/structural lumber.
Reply:You can certainly achieve the length your looking for in a steel member by welding pieces together. Having it all come out straight and inline is another question.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:This is an interesting thread. Isn't there going to be a problem with the haz area next to the weld weakening the base metal making the overall strength less than a full beam? I know the weld itself will be stronger, but I've seen a good many things crack right next to the weld due to the haz. And if he's looking for total beam strength, not just weld strength, won't he be putting himself at risk here? I'm certainly no expert on this so that's why I ask for clarification.Yeah, I know, but it'll be ok!Lincoln Square wave 255Miller Vintage mig30a spoolgunThermal Dynamics Pacmaster 100xl plasmaSmith mc torchEllis 1600 band saw
Reply:Originally Posted by RussZHCThanks drooopy, have to go looking having never seen finger jointed dimensional/structural lumber.
Reply:Originally Posted by welderjThis is an interesting thread. Isn't there going to be a problem with the haz area next to the weld weakening the base metal making the overall strength less than a full beam? I know the weld itself will be stronger, but I've seen a good many things crack right next to the weld due to the haz. And if he's looking for total beam strength, not just weld strength, won't he be putting himself at risk here? I'm certainly no expert on this so that's why I ask for clarification.
Reply:Originally Posted by motolife313If you put a bunch of clamps on it it should stay real straight.
Reply:Several pieces welded together will perform differently than an originally solid piece.How your design copes with these differences controls whether the final product fails in service or not.If you reinforce the joints properly, your composite could be stiffer than a single piece. But you still have to be very mindful of how the welding has disrupted the flexibility of a long, single piece.Be wary of The Numbers: Figures don't lie,. but liars can figure.Welders:2008 Lincoln 140 GMAW&FCAW2012 HF 165 'toy' GTAW&SMAW1970's Cobbled together O/A
Reply:Originally Posted by farmersammYou have a very valid point.  Spliced beams will fail with considerably less load cycles than solid/unspliced beams.  The only cure for this, as far as I'm aware, is to derate the load/cycle rating when considering the final design.
Reply:Originally Posted by welderjThis is why I'm a fan of plating the joints like this. It's not cure for every problem, but does give the opportunity to achieve full strength in many cases. Again, I have no official training so I'm not saying I'm right, that's just how I do it and my experience.
Reply:Like a fishing rod or a closet rod,,, one needs to flex, one shouldn't. The answer is "it depends". "The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:I find this question interesting and hope my input does not stray too far off topic.The building where I work is several hundred feet long, maybe 70 wide with a roof peak maybe 40 high.  The bulk of interior space has no posts so they used "I" beam shape beams but of welded/bolted together construction and no upright or angled member is a constant cross section.Today, because of this question, I deliberately took a closer look...the vertical/upright members are nearly all multi piece construction of the web but single piece flanges, the roof supporting beams also vary in cross section and are slightly angled with each angle made up of three pieces bolted together.  Discounting the bolted connections, each piece is made up of smaller pieces in both the web and the flange and all welded together (I assume off site originally).  The joints all appear to be in the middle third of the overall piece length (guessimating) but with the web joint and the flange joint staggered by roughly a third as well.  No joints that I could see close up were ground at all.The other thing I found was the three bolted together roofing support beams that make up the overall length of beam got shorter and shorter towards the peak of the roof (I have no clue what the engineering logic there is, if any).All welded joints, from what I could tell, were square butt with no or next to no scarfing and welded from both sides (impossible for me to judge if there would have been a gap between the plates originally).Last edited by RussZHC; 03-03-2015 at 03:14 PM.
Reply:Here's a GREAT read on beam splices in built up beams.  https://www.ideals.illinois.edu/bits...pdf?sequence=2I would imagine, off hand, that most spliced sections are quite good if they aren't expected to carry beyond the downgraded load capacity over time.  As long as you know it's a weak area, fatigue wise, I'd imagine you'd design accordingly.  Increasing beam height would remove a great deal of flex, and reduce fatigue I'd imagine.  Splices are pretty common, so there must be a designed load limit of some kind."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by farmersammHere's a GREAT read on beam splices in built up beams.  https://www.ideals.illinois.edu/bits...pdf?sequence=2I would imagine, off hand, that most spliced sections are quite good if they aren't expected to carry beyond the downgraded load capacity over time.  As long as you know it's a weak area, fatigue wise, I'd imagine you'd design accordingly.  Increasing beam height would remove a great deal of flex, and reduce fatigue I'd imagine.  Splices are pretty common, so there must be a designed load limit of some kind.
Reply:Wow, Thank You Guys. Yall make a good point about the I beams. I have enjoyed reading all your stories, interesting stuff lol. But in the end, is it actually a good idea to weld them together?
Reply:What about if you fish plate them all?
Reply:Finger jointed studs are only rated to be in compression, meaning they can only be used vertically holding something up, I would think it depends on what you plan on using your steel for, supporting something vertically , or with a side load
Reply:Beams are welded together all the time, however they are building a billion dollar plus ring road around Edmonton and some of the overpasses have HUGE beams that are riveted together. I saw the beams sitting on the side but I couldn't see if the were already riveted or that was done once they were in place. It makes sense they were riveted after being placed because it would be hard to get perfect 100% penetration all the way around and keep a consistent heat on the beams. They weren't on a trailer. The beams were the trailer. They just attached axles to the beam.Welds are stronger than base metal, no coverplating needed. You cannot buy plates longer than 86 feet and wider than 16 feet all are butt welded full pen and ground flush for UT or X ray. Very rare to stress relieve also.Been building bridges for104 years.Any bolt is stronger than a rivet.
Reply:104 years!  You deserve a break! 30+ yrs Army Infantry & Field Artillery, 25 yrs agoMiller 350LX Tig Runner TA 210, spool gunLincoln 250/250 IdealArcESAB PCM 500i PlasmaKazoo 30"  vert BSKazoo 9x16 horiz BSClausing 12x24 lathe20T Air Press
Reply:http://www.lcc.edu/manufacturing/wel...20-%202011.pdfA very good discussion about rivets.Riveting has succumbed to cheaper methods of fastening iron.  Cheaper in terms of labor....Drill some holes, and just about anybody can figure out how to install a bolt.  It takes a skilled crew do drive a single rivet.Bolts have also supplanted rivets, and welding, for quality reasons.  I don't care where you go, you'll always find work performed by manual labor that's substandard due to poor workmanship.  It's the reason for visual, and non destructive, testing/inspection of welds.  Human error, and plain lazy habits, takes its toll.  Can't be avoided.  Even bolts have had to be designed to be moron proof..........Huck fasteners are a prime example.It's all about time and money...........mostly money.Riveted structures, designed properly, have withstood the test of time.I'd bet the farm that the modern structures made of concrete (the worst), and welded/bolted structures, won't be around as long as the many riveted structures still in service.  Both bridges are riveted steel bridges.It's an axiom, everything will get cheaper over time.  Whether it's better is up for debate.  Experience tells us that, in most cases, if not all cases, it gets worse."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Originally Posted by TVGuideLet's say you have a bunch of 2 foot pieces of say square tubing or angle iron, can you weld 5 of them together to make it 10 feet and it be as strong as a 10 foot piece from the mill? The way I was thinking of doing it is by beveling it at an angle on both pieces and making the weld a little higher than the base metal. If you grind it down to smooth it, would it make it weak or is it okay?
Reply:Originally Posted by PavinsteelmanWelds are stronger than base metal, no coverplating needed. You cannot buy plates longer than 86 feet and wider than 16 feet all are butt welded full pen and ground flush for UT or X ray. Very rare to stress relieve also.Been building bridges for104 years.Any bolt is stronger than a rivet.
Reply:Hey, TVGuide.I re-read your original question, and I don't think you are going to be building bridges or buildings with these angle irons and square tube. So while this is a lot of interesting information, it is not answering your question.A friend gave me lots of short pieces of 1" square tube and I pieced it together for TIG practice. I squared the cuts, slightly beveled the edges, aligned the best I could, then tacked together and TIG welded to finish. Lots of good practice and I use these lengths for table legs or deer feeders, etc. While I think they are almost as strong as as new lengths, I would never use them for anything where someone could get hurt if it failed.So, I think the answer to your original question is YES, you can weld them and have good material for lots of uses, but not for critical uses.And while you are practicing welding you will learn lots about warping, clamping, tacking, etc.Burt _____________________Miller Syncrowave 250Millermatic 211Miller 375 Plasma Cutter Hobart Handler 12010FtDrillBit.com