Butt welding steel I beams

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Hello All,I want to butt splice two 6" I beams together to make one longer beam. Besides beveling the ends and welding all around, is there a way to "scab" flat plates on the sides to make it stronger? Is this even needed?I have some I beams spanning my garage for a storage mezzanine, and the splice in those are made on a diagonal and just a butt weld. Seems to have been holding for many years, but just wondered if there is a better way.I think I saw a post somewhere on here once, where someone posted a manual or link to a manual of some sort that showed different joint configurations for doing this. Unfortunately, I cannot find this post! I believe it said something about not welding the ends of the scab plates, just the top and bottom edges. I think i would overlap the joints by 12" or so on each side.I am building a small foot bridge over a creek. Liability is not an issue.Any advice or a link to a manual would be appreciated.Thanks
Reply:If you're not good with open root welding, you can cut bird's mouth in the web, and use a backing plate to weld the flanges, and a backing plate on the web. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Cep, could you take say a 12"x12"x1/2 or maybe 3/8" plate and phish plate that joint on both sides?I'm not suggestion but asking a question. Sent from my iPhone using Tapatalk
Reply:I don't see why not, it's done all the time on dirt moving equipment, excavator booms, etc. Just don't use 90-degree corners! Ovals, or diamond shape fish plates are always a good choice. I've never done it on a structural beam myself though.Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:In your situation I would plate the bottom flange. Get a plate a bit narrower than the beam and weld only the sides of it. If you feel you need to weld the ends for some reason cut a point on them so the welds don't go straight across. You won't get much benefit from plating the top as long as all the pressure is down on the beam. If you can't plate the bottom for some reason then plate on top of the bottom flange on both sides of the web.
Reply:Here is a detail out of a AWS D1.1 code book. This is for beefing up the capacity of beams for loads. But if your not confident in your welding ability it could help that too. I generally see them speced with 6 on 12 welds. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:On small beams like the 6 inch beams mentioned I like to cut the butt joints at a 45 degree angle. To me this puts the stress over a larger area and gives more surface area for weld. For a high stress application like a truck frame I would fishplate with a plate or piece of frame at least 3 times the height, 18 inch for a 6 inch beam.Miller xmt304,  Miller S22 p12, Miier Maxstar SD, Miller 252 w 30A, Miller super32p12, Lincoln Ranger 9, Thermal Arc 181I with spoolgun, Hypertherm 10000 ,Smith torches. Esab 161lts miniarc.
Reply:No need to be complex rat hole top and bottom 45 one side back up bar full pen flanges web vee a little hot pass both sides 3/16 6010 or lap plate and fillet weld around all stress is in flanges.
Reply:Explain why a phish plate corners should not be square. Do you only weld the web sides of the fish plate or all sides. Sent from my iPhone using Tapatalk
Reply:A weld across the flange causes a stress line where a crack can start, therefore should be avoided if possible. If you need to weld across any beam if you weld at an angle it minimizes that.
Reply:just do a 30 degree bevel on both sides of each piece with a 1/8 landing in the center. full pen .weld it out about a 1/16 proud of flush..7018 of course..face all times with a positive mental attitude,then and only then will you have done your best.
Reply:ThanksSent from my iPhone using Tapatalk
Reply:Originally Posted by papasmirfExplain why a phish plate corners should not be square. Do you only weld the web sides of the fish plate or all sides.
Reply:He is not building anything with a great load on it for crying out loud, if your not capable of securely welding theres no reason to keep adding to the piece. I bet you have a 6x12 or 6x13 I beam? Bevel both beams and run a 7018 around them and move on, worst case add a plate possible 12x6 to the web and stitch weld it, no need to over heat this little beam.
Reply:Here are some joint preps I use, depending on weight of beam. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Most of what's been said is good advice of a general nature, but without more info such as beam size and span length it's impossible to give much in the way of useful advice. The type of joint you will need will depend a lot on the size of beam and length of span. For instance if your using some scrap pieces of a large beam and have a shorter span then you might get by with just a welded joint. But if your using lighter beams or longer spans then a welded only joint may not hold regardless of what you use to weld it, plating will be necessary there. Plating the web will help some to strengthen the joint but won't give maximum strength.
Reply:Originally Posted by CEPHere are some joint preps I use, depending on weight of beam.
Reply:there's several ways to splice "H" beams depending on span and load. are you doing this on the ground or in place? if the welding is being done up in the air make that bottom re-enforcing plate in cep's sketch wider than the beam so there's no over-head welding.i.u.o.e. # 15queens, ny and sunny fla
Reply:Originally Posted by Ultralow787Thanks Guys!  I guess it is just something about the plates on either side of the web that just looks like it would be stronger?
Reply:doc,I can flip it over and it will be joined on the ground. I like the 3rd version from the top of CEP's sketches. If i decide to add the fishplates to either side of the web, should they be diamond shaped, or can they just be pieces of say 4" x 1/4" (or3/8")flat bar about 18" long and have only the top and bottom edges welded (Assuming the beam is standing and we are looking at the side)? I have been told that if the vertical ends of the fishplates are welded, then there are added stress points. I would add these fishplates along either side of the joint with 9" on either beam. i would make sure the welds on the web are flat so that these plates could lay nice and flat. I have seen the joints made like the first picture CEP posted near the top of this thread with the backer plates on each weld as well.Thanks
Reply:Originally Posted by welderjPlating the web is not as strong in your case as plating the flange. The flange carries the weight, the web is mostly to hold the flanges apart and parallel, so for max strength you need the flanges to be strong.
Reply:Rectangle plate is fine just weld like you stated. You will have to grind or torch a small backbevel to get the plate tight to the web. 1 side is more than adequate for what you are doing.Miller xmt304,  Miller S22 p12, Miier Maxstar SD, Miller 252 w 30A, Miller super32p12, Lincoln Ranger 9, Thermal Arc 181I with spoolgun, Hypertherm 10000 ,Smith torches. Esab 161lts miniarc.
Reply:That would be best. You can cut a point or radius on the end as well. I prefer no end welds unless corrosion is a problem.
Reply:Originally Posted by welderjPlating the web is not as strong in your case as plating the flange. The flange carries the weight, the web is mostly to hold the flanges apart and parallel, so for max strength you need the flanges to be strong.
Reply:A “PE” used this analogy to explain to me how a beam fails under load. Take a yardstick, support the ends, push down in the center of the yardstick, what happens? The yardstick bows out to one side or the other. It doesn't go straight down. It bows out to the side until it buckles. So if you beef up the flanges of the beam. Or box the beam in some how. The trick is to keep the beam from bowing to the side. The web has little effect to the strength on the beam.  Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400Originally Posted by Drf255Is this true?  It appears opposite to me, but I'm not an engineer.  I thought that the web carried the weight and the two flanges kept it from twisting.  Please explain.
Reply:If you go right down a load chart, the same height W-Shape will carry more weight then the same height S-Shape. Don’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Being an Ironworker welder, I do this type of work frequently. How is this beam going to sit in position? Flanges on top and bottom? If that's the case, bevel it all, but it up and do a basically full pen weld with nothing but 7018 stick rod. The beam flanges support any top or bottom load on the beam. If the welds are done correctly, there's no need for extra plating and welding.Be sure to weld all the way around, both sides.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by snoeproeIf the welds are done correctly, there's no need for extra plating and welding.
Reply:Do pipe welders weld extra plates or extra stiffeners on the sides of their full pen pipe welded joints because they are worried about the HAZ? No. They don't. I've splice welded lots of structural steel I beams on code jobs and I've never added extra plating to them after. Then again, I'm also an all position certified structural ticketed welder and every weld I make has to pass a quality control weld inspection.Last edited by snoeproe; 02-12-2014 at 10:40 AM.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:I guess the structural engineers do it differently here in texas then, over the last 5 years they went from placing i beams on top of columns to only welding a single weld plate to the column and to one side of the I beam webbing. The flange does not get any weld. This is residental and commercial practice.
Reply:The bottom line here is the op has to have the skills to weld this beam splice correctly. If he doesn't have those skills he would be better off drilling 2 holes in the beam ends and using a plate on one side of the webbing to connect the bolt the beams together.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by Ultralow787doc,I can flip it over and it will be joined on the ground. I like the 3rd version from the top of CEP's sketches. If i decide to add the fishplates to either side of the web, should they be diamond shaped, or can they just be pieces of say 4" x 1/4" (or3/8")flat bar about 18" long and have only the top and bottom edges welded (Assuming the beam is standing and we are looking at the side)? I have been told that if the vertical ends of the fishplates are welded, then there are added stress points. I would add these fishplates along either side of the joint with 9" on either beam. i would make sure the welds on the web are flat so that these plates could lay nice and flat. I have seen the joints made like the first picture CEP posted near the top of this thread with the backer plates on each weld as well.Thanks
Reply:Originally Posted by snoeproeDo pipe welders weld extra plates or extra stiffeners on the sides of their full pen pipe welded joints because they are worried about the HAZ? No. They don't. I've splice welded lots of structural steel I beams on code jobs and I've never added extra plating to them after. Then again, I'm also an all position certified structural ticketed welder and every weld I make has to pass a quality control weld inspection.
Reply:Originally Posted by kkustomzI guess the structural engineers do it differently here in texas then, over the last 5 years they went from placing i beams on top of columns to only welding a single weld plate to the column and to one side of the I beam webbing. The flange does not get any weld. This is residental and commercial practice.
Reply:Originally Posted by snoeproeDo pipe welders weld extra plates or extra stiffeners on the sides of their full pen pipe welded joints because they are worried about the HAZ? No. They don't. I've splice welded lots of structural steel I beams on code jobs and I've never added extra plating to them after. Then again, I'm also an all position certified structural ticketed welder and every weld I make has to pass a quality control weld inspection.
Reply:Originally Posted by welderjWhat does pipeline welding have to do with weight carrying I-beams? They are welded to prevent leaks not for weight carrying so there is little similarity there. There is also no way that you can weld a but weld without heat stressing the steel next to the weld, so there is no way that a welded only but weld can be as strong as a full span beam with no joint unless it's plated. And it makes no difference how many certs you have or what welding process or rod you use, the heat stress is a fact. If you weld but joints without plating it's because it's not necessary for the beam to be full strength. So as I said earlier, he needs to decide how close he is to the max load on his beam to determine what is the proper way to do the joint.
Reply:Originally Posted by CEPOh my God! You need to stick to driving truck! This is so far over your head!
Reply:Originally Posted by welderjSo explain it then to this uninformed simpleton, how do you get past the heat stress damage at the weld line that will weaken the beam to less than it original strength? Unless the laws of physics don't apply in your world there is no known way to avoid that.
Reply:Originally Posted by CEPYou're a fool! I'm not wasting my time trying to educate a fool. Go find a truck driving forum, and stick to what you know best! Leave the welding to us who do / did it for a living!
Reply:Hey, guys, we are all here to learn. If you think you can't learn something new or provide what knowledge you believe you have then the others of us don't want to listen to any arguing, fussing, and fighting. I know I'm only a 63 year old no nothin Okie ac farmer welder, but these discussions help me. Sssssoooo????Sent from my iPhone using Tapatalk
Reply:Originally Posted by papasmirfHey, guys, we are all here to learn. If you think you can't learn something new or provide what knowledge you believe you have then the others of us don't want to listen to any arguing, fussing, and fighting. I know I'm only a 63 year old no nothin Okie ac farmer welder, but these discussions help me. Sssssoooo????Sent from my iPhone using Tapatalk
Reply:Well?If he is making them longer (welding two together).Then shouldn't they have a bow(arc) up?I did one thirty years ago for a fellow, welded 2 twenty footers to go forty feet.I laid them out level, squared and beveled, then put 1 inch riser blocks under the weld area.Reground everything to match the butts, pushed them together, then welded and fish plated.Next I did the cross channels.When it was all done, we had a big long rectangle.We hooked a couple of tractors to it, dragged it over the creek.He planked the floor over the next couple of days.Measuring off from the same rock in the creek bed.Checking to see if the beams were sagging, then drove his Dodge 3/4 truck over it.Stopped in the middle measured said the sag looked level.Cut a big load of wood, drove back over it, measured it, sagged less then an 1 inch.He used that bridge for a couple of years till a Flood moved it a mile down stream and wrapped it around a tree!Bottom line is.Should the OP arch his spans?
Reply:Originally Posted by welderjSo you don't have an answer then, that's what I thought. I have an actual answer, so unless you can dispute that then maybe you should stop trying to confuse the situation. You could cause someone like the original poster to get in a bad spot by not doing his project properly.
Reply:Originally Posted by CEPWell Jon like you told me before, I don't have a clue how to build anything with out blue prints. Just how many full pen splices have you made on structural beams? Like I told you before build a few of these, then get back to me. Just get a job as a labor on any project like these, it will educate you. Stick to driving truck, every time you open your mouth here you place your foot in it.
Reply:Originally Posted by welderjSo explain it then to this uninformed simpleton, how do you get past the heat stress damage at the weld line that will weaken the beam to less than it original strength? Unless the laws of physics don't apply in your world there is no known way to avoid that.
Reply:I am interested in this topic, here are a couple quotes for discussion from: Steel Bridge Design HandbookNovember 2012U.S. Department of TransportationFederal Highway AdministrationSplice DesignPublication No. FHWA-IF-12-052 - Vol. 14In order to join pieces of a particular girder component (web or flange) together in the fabrication shop, shop splices are made. These shop splices are generally complete joint penetration (CJP) butt-welded splices. Typically, groove welds are utilized to join the pieces together. It should be noted that once the individual components (web or flange) are complete, they are typically welded together with fillet welds (flange-to-web welds).
Reply:Originally Posted by weldermikeEver hear of thermite welding? No? Then watch how you talk with people. They have been welding train rails together for years now. Same princible. High speed passanger trains up on bridges that go over long stretches of water. Go argue with those guys and see how quick you get your azz handed to you.
Reply:Jon please do me a big favor? Pull out your AWS Structural Welding Code book, scan the details they have in there for using fish plates on full pen beam splices, and post them here. I looked in my books and I just can't find it. Attached ImagesDon’t pay any attention to meI’m just a hobbyist!CarlDynasty 300V350-Pro w/pulseSG Spool gun1937 IdealArc-300PowerArc 200ST3 SA-200sVantage 400
Reply:Not that I really know anything about advanced welding, but wouldn't CEP's method of beveling the edges be the best possible way to join structural steel like an I-beam? It seems to me you'd want it to end up being essentially one long single piece of metal, instead of two separate beams joined by fillet welded backing strips. Not trying to correct anyone here, just bouncing my own thoughts off the more experienced folk.