make h beams stronger

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my gooseneck trailer has 8" beams 34 ft long, i need to strengthen them so not to bow down so much when loaded, one beam stayed bowed on last load,    i was thinking of getting 3/16 plate that would just squeeze inside the leg and weld it in place by 3" skip welds, the beams legs look 1/4,     would this work?
Reply:That will help. You can also build a truss. 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:This is what you want to do: (from http://www.pjtrailers.com/trailers/goosenecks/, or image search under frame bridging)edit: Obviously CEP got there first!XMT 350 MPA Dynasty 280DXSuitcase 8RC / OptimaSpoolmatic 30AThermco Ar / C02 mixerAssorted O/A gear
Reply:Heat straighten beam weld a bottom flange cover plate skip weld ok better fillet welded continuous. You can also heat camber beams .
Reply:Originally Posted by PavinsteelmanHeat straighten beam weld a bottom flange cover plate skip weld ok better fillet welded continuous. You can also heat camber beams .
Reply:Wish I had a dollar for every beam I've done this to.  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:Originally Posted by CEPWish I had a dollar for every beam I've done this to.
Reply:I did this a lot for bridge falsework. Never did this on the job, but for home projects when skip welding I use caulking between the welds before painting. 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:Originally Posted by CEPI did this a lot for bridge falsework. Never did this on the job, but for home projects when skip welding I use caulking between the welds before painting.
Reply:Originally Posted by CEPWish I had a dollar for every beam I've done this to.
Reply:Originally Posted by docwelderi've done this a few times also. if the engineer is thinking and space allows he makes the bottom plate wider to eliminate overhead welding.
Reply:Originally Posted by docwelderi've done this a few times also. if the engineer is thinking and space allows he makes the bottom plate wider to eliminate overhead welding.
Reply:Originally Posted by CEPWish I had a dollar for every beam I've done this to.
Reply:Originally Posted by docwelderi've done this a few times also. if the engineer is thinking and space allows he makes the bottom plate wider to eliminate overhead welding.
Reply:Originally Posted by gxbxcIf the engineer was thinking it would have been done at time of manufacture ,not in the field after the fact.
Reply:Originally Posted by Tat2dHandzCan this be applied to I beams as well? Just a question in general because I know there's so many different applications where I beams are used.
Reply:Originally Posted by gxbxcIf the engineer was thinking it would have been done at time of manufacture ,not in the field after the fact.
Reply:All the methods work.Two of the methods are covered here.  Strongback, and bridging.  Both on the crane, and on the strongback on the loader frame.  Crazy picture is an old 35mm from about near on 15-20yrs ago.  Geez, time passes in a heartbeat.  Been a long time since I built that crap  Only had a cutting torch, AC crackerbox, and a small drill press back then.I'm not sure that I completely trust either method as far as it goes (I'd get real picky about the actual ratings).  Don't get me wrong, they're accepted methods.  Both methods are subject to local collapse.  The bridging I believe would be the worst, with the endmost uprights collapsing first where the force "turns the corner".  The straight plate strongback is only as strong as its ability to remain absolutely perpendicular to the beam, once it moves out of line it will fail.I tried the coverplate method many years ago too.  As always, on my dime.  You can tell me something, but I have to see it to believe it.  In this case I reinforced the side of a column that was in tension with a very minimal piece of 3/16 flat stock.  This allows a piece of 3" channel to do work it otherwise wouldn't do.  Holds about a ton or better regularly (my materials rack in all my pics) with no complaint in a cantilever situation.  Another one of those "Geez, where did the time go" things."Any day above ground is a good day"http://www.farmersamm.com/
Reply:An unsupported beam will fail like a yard stick. The flanges fail first, and the beam will roll to one side. That's why an H-beam will take more load than a S-shape. Beefing up the flanges is a big help. 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:The flanges will fail.  Sometimes the web can fail when it buckles, despite robust flanges.Flange can stay intact (no tensile failure) while the web has buckled.  It's the downside of reinforcing the flange, and expecting it to work miracles.  Flange may still resist force due to the increased tensile strength, but if the web is too shallow, it's all for naught.  It's a fascinating system that takes understanding of physics to understand.  I wish I was truly conversant in physics, but I'm not.  Separation of the 2 flanges, in terms of distance, is something I'm not well educated on, wish I was."Any day above ground is a good day"http://www.farmersamm.com/
Reply:Docwelder I see your point when some one on Park Ave wants a swimming pool on the 23 floor all bets are off, but I read that the old Waldorf Astoria hotel ballroom had the Budweiser Clydesdale hitch preforming up there.gxbxc
Reply:If engineers were smart they would just spec a proper sized beam.Millermatic 252millermatic 175miller 300 Thunderboltlincoln ranger 250smith torcheslots of bfh'sIf it dont fit get a bigger hammer
Reply:Originally Posted by farmshopIf engineers were smart they would just spec a proper sized beam.
Reply:Years ago coverplated wide flange beams were common ,now they build girders . Top flanges are stronger from shear studs in the deck and bottom flanges are coverplated . Webs just hold the flanges apart and be.of lower thickness of steel.
Reply:so, if i weld to bottom flange only with maybe some jacks in the middle jacking upwards it might actualy bow my trailer upwards in the middle like i need, right now they have a slight bow in the middle down from a heavy load, also if i box in one side would what would be a better thickness to use   like 1/4 or 3/8 thick,   i dont want it bowing again so after boxing im going to truss the bottom and may add a torque tube in later as well.Originally Posted by wedge542so, if i weld to bottom flange only with maybe some jacks in the middle jacking upwards it might actualy bow my trailer upwards in the middle like i need, right now they have a slight bow in the middle down from a heavy load, also if i box in one side would what would be a better thickness to use   like 1/4 or 3/8 thick,   i dont want it bowing again so after boxing im going to truss the bottom and may add a torque tube in later as well.
Reply:how thick on the plate to box in with?
Reply:Personally, I'd take the bow out first with heat shrinking. Then plate it, or build a truss. 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:i cant figure out where to heat it at,   ive got a 20 ton porta jack on it now with a 20 ft ind chain, im almost at 12 tons presure now and its straight but if i let off it goes back,         its bowed down towards the ground and not sure if i need to heat top or bottom or web?
Reply:heat the bottom
Reply:Do you know it is actually easier to heat shrink a beam than draw on the dam computer! I'm much better with a piece of soapstone, and a concrete floor. I hope we're on the same page here. I'd crawl under the trailer, heat the underside of the bottom flange red hot. Then heat both sides of the web in a upside down V shape. Let cool to the touch before moving to the next spot. With out seeing the trailer it's hard to say, but I would start out with heating a 3 to 4-inch wide spot on the bottom flange, and an upside down v all the way to the bottom of the top flange.Now is that about as clear as mud​​? 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:Originally Posted by CEPDo you know it is actually easier to heat shrink a beam than draw on the dam computer! I'm much better with a piece of soapstone, and a concrete floor.
Reply:I can do pretty good with Auto-Cad. But what a process to convert to a jpeg!  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:That looks pretty cool - though I've never used a CAD anything.I tried once with an online version...came pretty close to dousing the computer and desk with gasoline and lighting it on fire.... Decided paper and pencil is safer in the long run Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:thank you very much cep,  i wish you was closer,id hire you to do this,   i heated today till ran outta gas, almost got my porta power presured out, i heated and heated and waited 3 hrs,let off porta power and right back to where it started,bow in middle towards ground,   ill get more gas and try again,i dont think i got red hot like you said on bottom flange, i was afraid id get so hot it would just colapse.  You think id do better without the chains and jack because thats scary jacking that thing and something is moveing because i used all the ram the jack had, i thought chain stretching but it looks good.    Chains 20ft long and i had jack in middle forcing it upwards, heard alot of poping,crackling sounds and frame was straight for awhile.  Please dont give up on me and leave,   i got more questions after i get this done.     Again thanks for your help everyone here.
Reply:You are using oxygen & acetylene to heat with, correct? I don't like heat shrinking with oxygen & propane. And you are using a rose bud to heat with, correct? 8” beam is a little big for a large cutting tip. Depending on how much the beams are bowed, if there is not a real bad bow, you might get away with just heating red circles on the underside of the bottom flange. The technique I showed in that drawing is very aggressive! This is a #12 rose bud, they can really put out the heat. With a guy working on the opposite side with his own #12 rose bud I've straightened 36” beams in the past. 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:Oh I forgot, through out all of this I forgot to mention to use water to cool the heated zone. With an 8” beam I might use a garden hose, but laying on the ground that will get messy fast. Most of my smaller stuff I use a spray bottle of water. 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:I know my question is stupid. Are these beams ordinary rolled steel, or high strength steel that would require specialized technique?
Reply:My friends have a 50 ton Talbert trailer. It had structural damage, as I remember from dragging over a hump in the road. After turning it upside down for better access they did some research learning this was some specialized steel requiring large mass preheat, and specialized wire. I wasn't there, but in the retelling it was pretty complex. They hauled it to a specialist 100 miles away.
Reply:Originally Posted by wedge542thank you very much cep,  i wish you was closer,id hire you to do this,   i heated today till ran outta gas, almost got my porta power presured out, i heated and heated and waited 3 hrs,let off porta power and right back to where it started,bow in middle towards ground,   ill get more gas and try again,i dont think i got red hot like you said on bottom flange, i was afraid id get so hot it would just colapse.  You think id do better without the chains and jack because thats scary jacking that thing and something is moveing because i used all the ram the jack had, i thought chain stretching but it looks good.    Chains 20ft long and i had jack in middle forcing it upwards, heard alot of poping,crackling sounds and frame was straight for awhile.  Please dont give up on me and leave,   i got more questions after i get this done.     Again thanks for your help everyone here.
Reply:Originally Posted by MinnesotaDaveUsing the heat shrink techniques CEP is describing, you won't need chains and jacks Check out this video, it may help you visualize as well:
Reply:You do want to support it so gravity doesn't take over when it is soft. One of Jody's videos drove it home. He was straightening a shaft. He used a dial indicator, and rotated the shaft to determine what was needed. As I recall, he got within .020 or so. The machinist planned to take off more than that anyway. I'm betting Zapster could add some information. When I tried the shaft straightening technique I gained a bit each re heat, but with 28 people who don't get paid if chips aren't coming out the pipe I gave in and used the hydraulic press. It worked fine a couple of months, didn't fail but got replaced just in case, as the machine was being dismantled and repurposed.The shrinking of cooling metal is a source of frustration to me. The fact that someone can use the predictable nature of this evil force to do good, is magic.