Semi truck aluminum frame repair

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I think I may have come across one of those jobs where it pays to walk away. So any input would be useful. This customer wants me to repair these cracks in the aluminum frame of his semi flat bed trailer. The frame is extruded T6 6061 aluminum. The stress cracks are located right above the wheel perches of axle. (Where the axle assembly bolts up to the aluminum frame rails)On the one side, the bottom lower flange is fully cracked across (picture provided). This lower flange is about 3/4 to 1" thick aluminum. The web of the frame is 1/4 inch. It appears the weld has cracked in the HAZ closest to the welded cross member. The vertical crack is about 8 inches long, the other cracks that run parallel with the frame are about 6 inches long. I assumed this happened because there's a ton of electrolysis between the frame and the axle mounts. The frame 6061 aluminum and the axle perches being steel. It looks like it actually pushed a gap between them which caused play? This then may have caused the cracks? but this is not certain.   So I have to repair both sides. I am thinking this is a can of worms job. what would you guys and gals think?Greg Attached Images
Reply:I wouldn't want to be the guy that welded it and had it fail the next time he overloads it.
Reply:I vote to walk, too much liability.   Whether overloaded or underdesigned, if you fix it there it may break elsewhere.RichardSculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge
Reply:I usually think to myself "if I owned it, would I weld it?"  Dave J.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:lolololol Dave J. that was great. It's ironic because I said to the customer, even if it was my truck I'd sell it.
Reply:That one is worse than the one I turned down. Junk it .Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:I read you post to the point of "alum flat bed trailer" that's enough right there... That trailer was way overloaded or is just plain old and beat... I'll guarantee that the trailer has those cracks all over it.... Walk Away !!Lincoln pro mig 180Lincoln Square Wave Tig 300/wp 20/home built water cooler Victor, Purox, Harris, O/A welding/cutting setupsVintage Craftsman drill pressVintage Craftsman/Atlas 12"x 36'' lathe7''x 12'' w/c band saw Everlast 140 st
Reply:Originally Posted by lovetoweldlolololol Dave J. that was great. It's ironic because I said to the customer, even if it was my truck I'd sell it.
Reply:walk away,  when they get to that point your just just going to be chasing cracks for the rest of daysVantage 500's LN-25's, VI-400's, cobramatics, Miller migs, synch 350 LX, Powcon inverters, XMT's, 250 Ton Acurrpress 12' brake, 1/4" 10' Atlantic shear,Koikie plasma table W/ esab plasmas. marvel & hyd-mech saws, pirrana & metal muncher punches.
Reply:Don't walk...RUNBuy American, or don't whine when you end up on the bread line.
Reply:thanks guys. thats what i figured. btw this guy wants this done on my portable rig! eeekkks!
Reply:Thats not a crack to be welded up, it needs a new section of frame married in. Not a fast job and has to be done carefully but can be done. Shop work not portable.
Reply:Originally Posted by 7A749I could see an emergency field repair with a spool gun to get the guy back to the yard, or wherever he's trucking from but otherwise, forget it.I've fixed mounting plates & stuff like that on aluminum trailers with good success, but not a big stress crack like that.Ditto. Leave it.IMHO of course
Reply:I concur with all the other members........that failure is not something to repair.I'm not even certain that the OEM of that trailer would even have a way to address all the potential problems that already exist in the frame sections ahead of and behind the visible fractures.The surface of the aluminum plate is so pitted that it took me a moment to decipher what I was looking at in the pictures.At first glance I thought there was a concrete block wall in the background because the aluminum is so heavily pitted.
Reply:Originally Posted by walkerweldI concur with all the other members........that failure is not something to repair.I'm not even certain that the OEM of that trailer would even have a way to address all the potential problems that already exist in the frame sections ahead of and behind the visible fractures.The surface of the aluminum plate is so pitted that it took me a moment to decipher what I was looking at in the pictures.At first glance I thought there was a concrete block wall in the background because the aluminum is so heavily pitted.
Reply:Do it! Just fish plate the entire lenght of the frame afterward with aircraft quality aluminum. Hahahaha!
Reply:Originally Posted by lovetoweldI think I may have come across one of those jobs where it pays to walk away. So any input would be useful. This customer wants me to repair these cracks in the aluminum frame of his semi flat bed trailer. The frame is extruded T6 6061 aluminum. The stress cracks are located right above the wheel perches of axle. (Where the axle assembly bolts up to the aluminum frame rails)On the one side, the bottom lower flange is fully cracked across (picture provided). This lower flange is about 3/4 to 1" thick aluminum. The web of the frame is 1/4 inch. It appears the weld has cracked in the HAZ closest to the welded cross member. The vertical crack is about 8 inches long, the other cracks that run parallel with the frame are about 6 inches long. I assumed this happened because there's a ton of electrolysis between the frame and the axle mounts. The frame 6061 aluminum and the axle perches being steel. It looks like it actually pushed a gap between them which caused play? This then may have caused the cracks? but this is not certain.   So I have to repair both sides. I am thinking this is a can of worms job. what would you guys and gals think?Greg
Reply:We have actually went out with the low boy and got them completely broke and put them back together.  Again, it takes time but no biggie.  No heat treating, no sectioning nothing like that.  Just remember the fish plates go on the inside web, not the outside and prep is everything.
Reply:SidecarFlip - "We do them all the time (in the shop) not portable and worse than that, much worse. " That was a very interesting and informative post.Dave J.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:Thats how it's done.  I didn't go through every little detail but then I expect a professional business owner who welds to understand that.It looks intimidating at first, but it really isn't.  With the exception of Reitnauer (which are built up sectional frame rails), they all repair the same.  With Reitnauer, you remove bolts and replace sections.  Problem is, Reitnauer uses stainless cap screws and they get corrosion welded to the aluminum, so, you have to cut and drill them out..TIG looks nice but Pulsed MIg is faster, much faster and the finished weld looks just as good.  We started out with standard MIG but got on board with the pulsed technology.Again, your filled and ground outer web and flange is for DOT looks, nothing more.  The fish plate carries the load as well as the lower, welded on strap.The welds have to be continuous, not stitch and I can't emphasise enough about the prep.Last edited by SidecarFlip; 03-18-2013 at 09:10 PM.
Reply:Sidecar. Lots of good info in that post. Beyond anything else it shows while many things are doable, it takes proper knowledge, skill and prep to pull off jobs like this. That's often why many members often strongly suggest  that people walk away from some projects or simply take it to a "pro" who specializes in these sorts of projects. It's not just slap any old weld on or toss some stiffening plates on and they are good to go... I'm betting there are still quite a few critical details that you left out simply for simplicity and clarity of the post.I know many times even those who "know" how to do jobs like this often shy away from posting up publicly how to do them. It's not that the information is "secret", it just that if not done properly, there is a huge potential for disaster and serious injury if proper procedures, pre/post heat, Interpass temps, materials, filler and prep aren't followed, especially if the welder doesn't have experience with the process or the skills to pull it off. A little information is sometimes more dangerous than simply saying "no, it can't be done..." You see it all the time here with so many simple projects, even when posters are given detailed information on how to do it right, they want to cut corners because the material or filler is too expensive or hard to locate, or they just don't have the proper equipment, so they just "wing it". "Close" just won't cut it many times with these types of jobs..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Wow sidecar. I'd like to have a hand in a project like that! That's pretty awesome
Reply:We use Tarp Stop Curtain Systems in Perrysburg, Ohio and Quick Draw out of Detroit. (Dearborn), Michigan.
Reply:Originally Posted by SidecarFlip  BTW. we use ESAB wire.
Reply:Originally Posted by DSWSidecar. Lots of good info in that post. Beyond anything else it shows while many things are doable, it takes proper knowledge, skill and prep to pull off jobs like this. That's often why many members often strongly suggest  that people walk away from some projects or simply take it to a "pro" who specializes in these sorts of projects. It's not just slap any old weld on or toss some stiffening plates on and they are good to go... I'm betting there are still quite a few critical details that you left out simply for simplicity and clarity of the post.I know many times even those who "know" how to do jobs like this often shy away from posting up publicly how to do them. It's not that the information is "secret", it just that if not done properly, there is a huge potential for disaster and serious injury if proper procedures, pre/post heat, Interpass temps, materials, filler and prep aren't followed, especially if the welder doesn't have experience with the process or the skills to pull it off. A little information is sometimes more dangerous than simply saying "no, it can't be done..." You see it all the time here with so many simple projects, even when posters are given detailed information on how to do it right, they want to cut corners because the material or filler is too expensive or hard to locate, or they just don't have the proper equipment, so they just "wing it". "Close" just won't cut it many times with these types of jobs.Originally Posted by shovelonWhat kind of Esab wire?
Reply:I read this site quite a bit but I don't post much.  However, this thread drew me like a moth to a candle......
Reply:Originally Posted by SidecarFlipThats how it's done.  I didn't go through every little detail but then I expect a professional business owner who welds to understand that.It looks intimidating at first, but it really isn't.  With the exception of Reitnauer (which are built up sectional frame rails), they all repair the same.  With Reitnauer, you remove bolts and replace sections.  Problem is, Reitnauer uses stainless cap screws and they get corrosion welded to the aluminum, so, you have to cut and drill them out..TIG looks nice but Pulsed MIg is faster, much faster and the finished weld looks just as good.  We started out with standard MIG but got on board with the pulsed technology.Again, your filled and ground outer web and flange is for DOT looks, nothing more.  The fish plate carries the load as well as the lower, welded on strap.The welds have to be continuous, not stitch and I can't emphasise enough about the prep.
Reply:Originally Posted by SidecarFlipI have to go look.  It's sunday and I'm not at work.  be there tomorrow.
Reply:Originally Posted by SidecarFlipI read this site quite a bit but I don't post much.  However, this thread drew me like a moth to a candle......
Reply:Originally Posted by shovelonThat's cool. I think you mean Monday?
Reply:Originally Posted by jamesyarbroughYou should probably post more.You guys work on steel too or just aluminum?
Reply:Originally Posted by lars66What wire # do you use, the East recommended wire # or something else?The way we removed bolts in Alum. frames was by heating them enough to swell them in the hole letting them cool and punching out.
Reply:So when you guys repaired steel trailers did you only fish plate the inside of the frame as well?
Reply:No.  We stringer welded the webs Inside and Outside, ground down the welds flush and laid a gussett (the widrh of the flange to the web vertical on the outside, welded that gusset in at a right angle (T) to the flange (no matter how the crack angled) trying to bridge the crack equally and then strapped the lower flange, usually with a strap equal to the original width of the flange itself, extending at least 3 feet each way of the break.  Unlike strapping the aluminum flange, we stitch welded the strap.  If you continuous weld the strap, you run the risk of arching the rail because the heat will cause contraction as it cools.If you look at a Transcraft rail, thats the principle, minus the holes of course and Transcraft uses the webs to support the rail standoffs, something I don't like.  Geat place to store blocking but if you roll a coil off the deck, the trailer is junk.
Reply:The only time we fishplated a steel frame inside was if the break occured directly over the suspension mounts on the lead axle because thats where the most torsional flex is when the trailer is loaded.  If the frame broke ahead of the lead, we strapped and gusseted as explained above.  Same thing applies to a 3 or 4 axle.  Over the suspension mount, fish plate inside only.  Anywhere else, stiffener and strap.The vertical stiffener mitigates the crack flexing (and rebreaking) and the strap keeps things together..I've seen real heavy haulers apply a triangulated strap before the trailer breaks.  I know guys that double out and triple out and the only way to keep a trailer together is to strap it prior to, not after.
Reply:I can't say who I work for, thats against company policy.  Suffice to say, we have a large shop,  We have frame straightening in floor pulling capability too.I can tell you how we do it however.
Reply:I have welded truck frames before. With great success and never a return on my work. I am not encouraging anyone to take on something they are not qualified to do here.But I get so tired of reading things like "Run" , "Dont do it", "liability" geeze. Do you have any idea how many things are done on a regular basis NOW because some guy decided to figure something out, try it and prove it?I bet everyone said "NO! Do not cut a vehicle and make it a stretch limo." Now look how many coach shops do exactly that. Who makes a factory limo? Nobody that I know of. I wish people would clarify their answers like "Well, if you are not qualified to do it, then don't do it" as opposed to "Run"Why should someone run? Give more reason than liability. Some of us carry liability insurance. If the insurance company insures the welding of trailer frames, why would you run?Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:+10 on that.  It's nothing exotic material wise, just lots of common sense some good old fabrication skills and a good tape measure.....It certainly hepls to have the proper shop atmosphere too..  I certainly would not tell anyone to do it in the backyard.......We are insured as well.  You have to be today.  Customers know conming in that once broken, all bets are really off.Last edited by SidecarFlip; 03-20-2013 at 01:18 AM.
Reply:thank you for the words of wisdom. excellent advice. I really wanted to take this shop on because like you had mentioned, the welding is the easier part to me. The shop, dropping the axles, landing gear and leveling the bed on jack stands is my challange. I have a 1000 sqaure foot shop, not big enough for this job. Thanks, Greg
Reply:Originally Posted by lovetoweldthank you for the words of wisdom. excellent advice. I really wanted to take this shop on because like you had mentioned, the welding is the easier part to me. The shop, dropping the axles, landing gear and leveling the bed on jack stands is my challange. I have a 1000 sqaure foot shop, not big enough for this job. Thanks, Greg
Reply:I agree with sidecar. He seems willing to help you along with the project however I get the impression the client wants it done "down and dirty" not sure. If you can't get this to your shop and do it to your comfort level then probably not worth doing.
Reply:I live in new york. I told the customer that the job is a little larger than my capabilities at this point in my career. I really wanted to weld this trailer up and make a good amount of money, but doing it outside in the back of a yard seemed just plain stupid. I have a feeling this guy is one of them "scotch tape and bubba gum" type of guy. That has no money yet drives a 65k mercedes.
Reply:Originally Posted by shovelonWhat kind of Esab wire?
Reply:This has been a GREAT read.I won't purchase a "modern" trailer for just these reasons.  It's not the fabrication that worries me, but the welding process.  I'm simply not set up to do anything requiring gas, being outside 'n all.The old trailers were made out of steel under the 100k tensile range, and more user friendly to someone like me.On strapping the web flanges:I don't know about the different properties of aluminum, so I can only address steel.I read, in the installation instructions from Hutch, that it's not adviseable to weld parallel to the flange closer than 1" to the edge of the flange, or across the flange closer than 1" to the edge.  I followed this religiously.In a situation where the flange has to either be replaced, or repaired, I would assume you'd weld fully across the flange to close up the gap (there would be no alternative), then add strapping narrow enough to hold the 1" in from the edge on the parallel welds.Ie.  6" flange, 4" strapI've also held the same dimensions with web stiffeners required adjacent to the hangers.  I held them back 1" from the edge of the web.  Although it isn't recommended, I've also kept the welding out of the central axis of the web, skip welding upper and lower parts of the stiffener.  I've seen it done both ways (sometimes full length welds), but figure I'd rather be safe.  I really don't see that a full length weld would reduce localized buckling any better than reasonably sized stitch welds."Any day above ground is a good day"http://www.farmersamm.com/