Walk Through - Chassis Pipe Weld

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Hello, Its about time i learn how to properly fix this type of break, its pipe on a chassis. I have other pipe to practice on and also attached is a photo of my welder (MIG) Starting with prepping, first step sanding to remove all paint color or do i need to remove oils and such with a specific cleaner? Ive hack welded before but looking to do this the right way. Thank you.  . Attached Images
Reply:The correct way would be to cut that section of tubing out and replace it.Millermatic 251Spectrum 300 PlasmaEverlast PowerTig 250EXEverlast PowerCool W300Harris / Victor OACraftsman 13 Speed Drill PressProTools Air/Hydraulic Bender48" BrakeCompressor, Notchers, Grinders, etc.
Reply:^ What he said.
Reply:What they said.
Reply:Yep, agreed. Lot less headache later.
Reply:Would you guys remove the entire section of pipe, or just weld in a 'patch pipe'?
Reply:new metal cut it out remove/replaceidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:Replace the pipe..At least the weld didn't break..Why would you even need to ask with a username like you have?...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:yeah, replace the whole pipe.  Like they said and they said before them.--Wintermute"No man's knowledge here can go beyond his experience." - John Lockewww.improvised-engineering.comManufacturer Agnostic:Blood----------Sweat---------Tears----|------------------|----------------|----Lincoln Red, Miller Blue, Esab Yellow
Reply:Like they all said replace the pipe.Wow I have never seen this many people all agree on something on this forum
Reply:Originally Posted by Mega Arc 5040DDLike they all said replace the pipe.Wow I have never seen this many people all agree on something on this forum
Reply:I would explore why it broke and then determine if the design needs to be changed... thicker tubing, gusset.....I'm not a welder, but I do sit next to one at the bar.
Reply:Originally Posted by sanford02I would explore why it broke and then determine if the design needs to be changed... thicker tubing, gusset.....
Reply:That picture make a whole lot more sense "Right side UP"...Seeing as that break is right next to where your Panhard Bar mounts to the left side of the frame, you're gonna wanna get that broken piece of crap out of there, and as already stated, weld in a new piece.  Can't tell exactly from the pics if it is a fatigue fracture, or if you poked the wall, but either way, that is no good.If it were ME, I would remove the mount for your Panhard Bar, and then CAREFULLY cut through that piece of tubing with a Zip Cut just to see if it will lay back in line with each other, or if it twists out of alignement worse... Not much use in replacing that run of tubing when another part of the frame may be tweaked.I'd have to agree with Zap on this one in regards to someone not doing a proper Post Race inspection - That is NOT a new break, and should have been caught long ago.I appreciate that you are asking for advice, and that you have scraps on hand to practice on, but by the nature of this thread, and the questions that you have asked, it really doesn't seem that you are ready to weld on an active race car chassis when people's health and well being may be adversely affected by a mistake on your part.Sorry, stepping off of the soapbox now - I tried to keep it short and polite. Attached ImagesLast edited by Black Wolf; 11-13-2010 at 12:54 AM.Later,Jason
Reply:The mig is a 120 V ya219Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:It's not pipe, it's DOM tube.  Use pipe and you'll flunk inspection (hopefully) or have a serious failure that could end with you being liable for damages due to use of inferior materials.  Cut it out entirely, fishmouth the new tube, and weld the new piece in following proper procedure for the alloy, typically preheat to 125-150, keep the interpass below 400-500, and don't let it fall below preheat until welding is complete.  It may be a good idea to take it to a machine shop and have it MT'd after as well.
Reply:Originally Posted by zapsterReplace the pipe..At least the weld didn't break..Why would you even need to ask with a username like you have?...zap!
Reply:Originally Posted by 4x4_WelderIt's not pipe, it's DOM tube.  Use pipe and you'll flunk inspection (hopefully) or have a serious failure that could end with you being liable for damages due to use of inferior materials.  Cut it out entirely, fishmouth the new tube, and weld the new piece in following proper procedure for the alloy, typically preheat to 125-150, keep the interpass below 400-500, and don't let it fall below preheat until welding is complete.  It may be a good idea to take it to a machine shop and have it MT'd after as well.
Reply:Originally Posted by bert the welderNot being familiar with vehicle stuff, and for sake of learning something new, just wondering why something like that can't be repaired with a sleeve welded over? Against race regs? To close to the original weld joint?Thanks for the info.
Reply:Thanks norite. Makes sense. Originally Posted by noriteIn racing, every ounce of unnecessay extra weight is to be eliminated.  I think it is something like 10 lbs = 1 hp.  Also everything is built to a design calculated to carry only the load it needs to.  If you were repairing a farm wagon welding the tube and welding a sleeve over it to reinforce it might be acceptable.  But the repair is not predictable as to strength, stiffness etc. compared to a new piece of tubing.  Repairing the tubing may make it too stiff and strong and cause an unexpected failure somewhere else.  Also sleeving the repair will make it impossible to tell if the original tube has cracked again.I agree with the others that the tube needs to be replaced.  Analysis of the reason for the break may indicate a need for reinforcement or even larger or stronger tubing but to simply weld the crack with a sleeve over it is not acceptable for this.
Reply:Perhaps even a more important reason for not sleeving - you couldn't fit a sleeve over this particular break.  It fractured at the weld toe where the acute angle is.  There's nothing there to sleeve!
Reply:This is a fatigue crack . . . chassis tubing is not brittle.  If it was an impact failure, the tubing would be necked down or otherwise deformed next to the crack.  From the visible portion of the weld, it seems likely there was a crater or other defect at the start of the crack.  After the tube is replaced I would suggest adding a gusset.  If possible, the sides should be 4 inches long, stitch welded with the corner left open.Dynasty 300DXSmith He/Ar gas mixerMM350PHobart Handler 120Smith LW7, MW5, AW1A
Reply:Originally Posted by 4sfedIf possible, the sides should be 4 inches long, stitch welded with the corner left open.
Reply:Originally Posted by con_fuse9A couple of questions though, why "stitch welded with the corner left open"?  You also suggested 4 inches, I always heard equal to diameter of the tube.  Why 4"?  Would you say 4" if it was a 1" diameter tube or a 1.5"?Thanks
Reply:Originally Posted by 4sfedEnvision two rolls of paper with perforations.  One is perforated all the way across, the other intermittantly perforated . . .Originally Posted by TaidenWouldn't it be more likeroll #1: perforations all the way acrossroll #2: 1" of perforations, then a 1" cut, alternating
Reply:Cool! makes sense. are there any books that cover all these little fabrication tricks?
Reply:Carrol Smith has a good book called "Prepare to Win"Covers the correct processes for fabrication, plumbing, and mechanical repair on race cars.  Was written in the 70's, but all of it still applies today to tube chassis carsMechanical Engineer
Reply:Wow...checked back after quite some time, i took the first advice and replaced the tube, also took other advice of going to my fabricator to get it done...he cut it out and put a slug in the once side and strait into the part you can see...what you dont see is that the pice goes into a X...Since I posted I have started my own welding on the chassis.   Correct it was a fatigue crack, also possibility it started before it cracked all the way.  This was one of our first chassis, after this we pretty much put a hand and eye on everything weekly...it ened up getting hit in the end...but here is the full chassis to give you a better idea of everything....http://renningerracing.com/2010/sections/forsale.html (already sold)  we figured out this is one of the spots that breaks first and a true sign of the fatigue of the chassis. also your right its not pipe, DOM is what its called although someone said it was a process...a while back they used chrome molly but that split to easy. Additionally we have done that triangle method of welding the triangle pice between the bars, it works very well...some guys do it proactively in a couple spots, by the way nice welding on that brace...did you use a MIG for that? Finally, so far the MIG seems to work best with a little thicker wire..i think .30....ive taken some welding classes over the year and they had me doing stick welding with 7018 as the go to..tried about 15 others..the mig is much cleaner and easier...next class coming up is TIG welding....Thanks for all the feedback on this...i should have checked back more often...
Reply:DOM = Drawn Over MandrelMM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:I will apologize right at the start for Dressing you Down over this, but it has to be said. Originally Posted by 7racecar7also your right its not pipe, DOM is what its called although someone said it was a process...a while back they used chrome molly but that split to easy.
Reply:Originally Posted by Black WolfExcuse me but I VEHEMENTLY beg to differ...As Duane explained above (and Paul last year) DOM refers to a process - It creates "Seamless" Tubing and is readily available in Mild Steel or 4130 ChroMoly... The latter being preferred for weight savings and strength.The Opposite to DOM is ERW Tubing and it has a welded seam running the full length of the joint.  The ERW will split along it's length upon impact.  It is very unpredictable and DANGEROUS in this application.
Reply:Originally Posted by Black WolfI will apologize right at the start for Dressing you Down over this, but it has to be said.Excuse me but I VEHEMENTLY beg to differ...As Duane explained above (and Paul last year) DOM refers to a process - It creates "Seamless" Tubing and is readily available in Mild Steel or 4130 ChroMoly... The latter being preferred for weight savings and strength.The Opposite to DOM is ERW Tubing and it has a welded seam running the full length of the joint.  The ERW will split along it's length upon impact.  It is very unpredictable and DANGEROUS in this application.To my limited knowledge, working only in Canada with CASCAR and IMCA Canada and having friends in Drag Racing - ERW Tubing is NOT allowed on Motorsport Chassis for roll cages... DOM ONLY - Either Mild Steel or 4130 ChroMoly.  Some allow ERW Rectangular Tubing for frame rails to reinforce or replace OEM frame rails and front/rear clips, but NOT on the cages.  Sanctioning bodies CLEARLY define the size, wall thickness, specific materials to be used AND approved welding procedures in their rule booksAs someone who is meddling in the field of Motorsport Chassis Fabrication... Even if you are only a Driver - You disturb me greatly by your ignorance (lack of knowledge) regarding the materials you are to be using, and the history of the sport.  There is a wealth of knowledge on this subject readily available from Steve Smith Autosports among many other reputable sources - Jay Hedgecock Racing and several Vocational Tech Schools have Motorsports Programs... I would strongly suggest that you pour yourself over all of this information and LEARN what the heck you are doing before one of "Your" Chassis' has a Catastrophic Failure.I wish you the best of luck moving forward.
Reply:Found this"ERW stands for Electric Resistance Welded. This is a mild steel tubing that started out as a flat sheet of steel, formed into tubing and welded. DOM stands for Drawn Over Mandrel and it is actually ERW tubing that has gone through a second process that shapes and smoothes the tubing so that the walls are more uniform. This in turn makes the tubing stronger than the original tubing"So to correctly verbally describe the material I am using, I know that it is DOM, and know that it is mild steel.  Seems the process starts out from flat metal and bends to a pipe then welds. Is there another type of process to end up with a pipe using mild steel with DOM applied? Originally Posted by Mario428Your signatureYou put this at the end of all your posts? I assume so and then spout a pack of misinformation!!!!!   Guess your signature is correct, too bad it applies to you.Actually per SFI who writes the specs for drag racing chassis mild steel is allowed down to 7.50 ET (25.4 if you want to look it up) and ERW is fine just has to have the correct wall thickness. ERW will not split along the seam. Being careful bending it with the weld on the inside of the bend so it compresses does help the strength. Since most DOM is processed ERW it is hard to see the welded seam and can be bent with the welded seam in the wrong place.Actually "pipe" would be fine also, people dismiss pipe as an inferior product but have never looked at the properties of pipe and seen it is as good a quality as mild steel tubing. Possibly better because it is pressure rated whereas most ERW and DOM tubing is definitly not rated for pressure.
Reply:Originally Posted by 7racecar7Found this"ERW stands for Electric Resistance Welded. This is a mild steel tubing that started out as a flat sheet of steel, formed into tubing and welded. DOM stands for Drawn Over Mandrel and it is actually ERW tubing that has gone through a second process that shapes and smoothes the tubing so that the walls are more uniform. This in turn makes the tubing stronger than the original tubing"So to correctly verbally describe the material I am using, I know that it is DOM, and know that it is mild steel.  Seems the process starts out from flat metal and bends to a pipe then welds. Is there another type of process to end up with a pipe using mild steel with DOM applied?
Reply:Originally Posted by Mario428Your signatureActually per SFI who writes the specs for drag racing chassis mild steel is allowed down to 7.50 ET (25.4 if you want to look it up) and ERW is fine just has to have the correct wall thickness. ERW will not split along the seam. Being careful bending it with the weld on the inside of the bend so it compresses does help the strength. Since most DOM is processed ERW it is hard to see the welded seam and can be bent with the welded seam in the wrong place..
Reply:Last I read it was something like .125 DOM or .093 chromoly for cages/chassis.
Reply:Ahhhh 6 responses - Great.Jim (4sfed) I concede 100% that you are more accurate than I.  Posts made in haste while running out the door sometimes have errors.  I prefer seamless, and in my world that is what I think of when I say DOM, but again, you are more accurate.  Thank you for the correction.7racecar7 - Excellent research in such a short period of time.  You will not regret it.  This Mario428 fella even make a couple good points once you look past his childish nattering.  As for Pipe being "fine also" -  I'll leave that up to you to sort out. It may be good enough for the track at Oyster Bed, but you'll probably get DQ'ed and laughed off the Tech Pad at a real track.Don't get me wrong - I Love PEI (My wife is from Tyne Valley) but what passes around there as "Acceptable" for motorsports makes me cringe.  The Miller Boys, Cary Lenetine and some of the other fellas running the Late Models have fairly decent pieces, but the lower classes - OH MY... And I'm not gonna even MENTION the Mud Rooters Park at DeSable.Bottom line is to take the time to do the research and educate yourself with all of the complete and accurate information - It will fill VOLUMES of books, and no typed explanation on here will cover it all no matter how well-intentioned.This topic should have been addressed with much more time and thought than I had last night, but thankfully others have followed behind me to address and correct my errors, so it more or less worked out in the end.Have a Good Night and SAFE Racing.Later,Jason
Reply:Most of the circle track cars in the US use REW tubing for both the cage and chassis.  Many though are available with DOM cages as an add on.  In 10 years of racing I've never seen a seam failure on REW tubing.  Some stress cracks from impact and some crappy welds down in the hobby stock division.I went back to road racing this season and they require DOM cages.  You just need to check with where you run to see what they say you have to use.  The most important things are a good design, good welds and the correct material size.
Reply:Originally Posted by Black WolfAhhhh 6 responses - Great.7racecar7 - Excellent research in such a short period of time.  You will not regret it.  This Mario428 fella even make a couple good points once you look past his childish nattering.  As for Pipe being "fine also" -  I'll leave that up to you to sort out. It may be good enough for the track at Oyster Bed, but you'll probably get DQ'ed and laughed off the Tech Pad at a real track.
Reply:This turned out to be quite a thread. The chassis dealer lists their well crafted chassis as DOM but evidently there much more to it.  I can leave it at that, i wont be building one from scratch any time soon...or possibly ever.http://www.bicknellracingproducts.co...sis-mainmenu-5My initial intention for the thread was to basically ask about welding fixes. Meaning the stress fracture point I showed a picture of, also anything else that breaks, for instance the front clip gets a beating over the season and welds crack from impact at the joint say where on tube meets another. Is there any books out there that cover the proper way to fix issues like this and keep the structural integrity in place? Im looked at the books but most of them are from 1980 back, unless of you tell me the info is still good.
Reply:ther is Absolutely Nothing technology or manufacturing process wise which is newer than 1980 in your racecar, so all that old design and reference material is still as good as new.sheesh, you arent building a rocket ship.  when do you think we sent people to the moon?
Reply:Originally Posted by 7racecar7This turned out to be quite a thread. The chassis dealer lists their well crafted chassis as DOM but evidently there much more to it.  I can leave it at that, i wont be building one from scratch any time soon...or possibly ever.http://www.bicknellracingproducts.co...sis-mainmenu-5My initial intention for the thread was to basically ask about welding fixes. Meaning the stress fracture point I showed a picture of, also anything else that breaks, for instance the front clip gets a beating over the season and welds crack from impact at the joint say where on tube meets another. Is there any books out there that cover the proper way to fix issues like this and keep the structural integrity in place? Im looked at the books but most of them are from 1980 back, unless of you tell me the info is still good.
Reply:Originally Posted by 7racecar7Is there any books out there that cover the proper way to fix issues like this and keep the structural integrity in place? Im looked at the books but most of them are from 1980 back, unless of you tell me the info is still good.
Reply:Mr MarioCartI know a decent amount about Pipe - As much as I need to do my job,   We use primarily 2" up to an including 10" on some of the rental assets where I work.  Everything from schedule 40 to Schedule 160 depending on the application.  Use it for steam lines, suction lines, and pressure lines (Gas and Fluid)  Sometimes it is for water, sometimes for drilling fluids, sometimes for septic waste.   Some of the pipe is steel, some is ABS and some is PVC... None of it belongs on a Race Car.I personally have never used Steel Pipe on a Race Chassis nor have I even seen one that did.   Don't know why anyone would -  It's just not done out here.  I have worked with over-built, heavy cars in the past, and you end up fighting with a sluggish lead-slead that handles like an Outhouse on Wheels.  On a related topic - Years and Years ago we had some shady characters that went the "other way" and made some of their door bars and halos out of exhaust tubing to save weight but thankfully that was caught and done away with quickly too.  My personal opinion of using Pipe on a Race Chassis is pretty simple:  If you just wanna sit in a loud car while everyone passes you, knock the mufflers off your Minivan and park on the side of the highway. You'll save money and embarassment in the end.I do wish to specifically address one thing you said: local short track bullrings are the same no matter where you go and bad work gets done everywhere.
Reply:Man you have your hands full now there Jason..Pipe on a chassis?Yeah rite.Any inspector worth his weight in salt will REJECT anything remotely resembling PIPE and if they don't well shame on them..Tubing is the only accepted material and stick with the rulebook on what you want to do..It is after all YOUR safety that they want..Save the argument guys because I ain't listening....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by zapsterMan you have your hands full now there Jason..
Reply:Originally Posted by Black WolfI was in a rush and posted a response that was flawed in content and that did not convey my intentions correctly.
Reply:Originally Posted by dstevensIf you've worked on as many chassis as you claim you'd know that this is misinformation. No way to misinterpret that.  It wasn't even close.
Reply:thought this was relevant http://www.profabricationtechniques.com/tube-work/