Controlling Distortion

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Just one way to control distortion.  Most folks know this, but this is for those who don't.  Other ways to do it, but this sittuation didn't require it.Piece of plate welded onto one side of 3x3 square tubing.  Obviously it pulled the steel.  Bowed like a banana.  Heat has to be applied to both sides, or it distorts.The problem was solved by running 2 stringer beads on the other side of the tubing in order to shrink the metal, and draw it straight again. Use a straight edge, and find where the bend actually is, then run a bead to correct it, right on the high point of the bend.  Grind it down, and call it  a day.There's other ways to solve the problem, but this was the easy and fast way to do it in this circumstanceI call it "backbeading", don't know what the techinical term is.  Trued up nicely. Attached Images"Any day above ground is a good day"http://www.farmersamm.com/
Reply:Samm:Thanks. This is a perfect example of 'a picture is worth a 1000 words'.Bowed like a banana.LMAO!!  Man, it took me a long time to figure this out on my own. I call it "backbeading", don't know what the technical term is. I don't know the tech term either, but I think you nailed it. For the newer weldors "All welds shrink". If you don't 'backbend' it before you weld it; you will be 'backbeading' it after you weld it. Use a straight edge, and find where the bend actually is, then run a bead to correct it, right on the high point of the bend.Nothing like painting a clear picture. Your post would have saved me countless hours of agitation when I was trying to learn welding. Gotta luv the internet. Last edited by Craig in Denver; 10-18-2008 at 12:33 AM.9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:great idea never ran into that problem what thickness of tubing did u use? i usally use 1/4 or bigger. But good tip allround
Reply:Thanks for sharing.  That is one on the many methods I have used.  Great to know those straightening methods especially for repairs.  On new construction, anticipation and prevention are real time savers, however.  There are post on this forum on "Breaking its back" and a nice Jig by Brainfarth he uses on fencing.
Reply:Nice tip.Were those beads run using 5AWG or 4AWG leads or is it too early to talk about that yet?MM200 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:A good idea to remember.
Reply:Originally Posted by duaneb55Nice tip.Were those beads run using 5AWG or 4AWG leads or is it too early to talk about that yet?
Reply:Originally Posted by duaneb55  Nice tip.Were those beads run using 5AWG or 4AWG leads or is it too early to talk about that yet?
Reply:Originally Posted by metal doctorgreat idea never ran into that problem what thickness of tubing did u use? i usally use 1/4 or bigger. But good tip allround
Reply:Didn't mean bowed BY a banana.  Internet broken here.  Running at 4.8kbps.  Can't even get edits to go thru"Any day above ground is a good day"http://www.farmersamm.com/
Reply:A #2 Victor brazing tip will work quite well for .125" wall tubing.  Heat a wedge shape on both sides of the tube, then heat the side opposite the weld .  No grinding needed
Reply:Originally Posted by beboA #2 Victor brazing tip will work quite well for .125" wall tubing.  Heat a wedge shape on both sides of the tube, then heat the side opposite the weld .  No grinding needed
Reply:I have been in this industry for going on 17 years now and I have never seen this done before! I will keep this trick in mind!
Reply:VERY nice and instructional. Oxyacetilenic torch isn´t allways available. (Until you are from "The A team")Thanks!
Reply:I've also used my carbon arc torch to heat the backside of a weld to straighten warped pieces. Works as well as laying a back bead, doesn't require any grinding, and doesn't use any oxy/act.MM251, SP125+, Hypertherm 360, 180SD, old Sears 285 amp buzz box
Reply:I helped build the Fleetwood Homes plant in Elizabethtown, PA back in '93.  Been in there many times for "refits" over the years.  One of the things they do while building the chassis's for the homes is running beads on the I beam flanges with 1/4" 6013 rods to create a "camber" in the frame.  Frames are fabricated upside down, in a jig, and then flipped to the waiting axles.  When the house is completed on the chassis, the weight will straighten the frame for transportation.  I once had to travel almost to the NYS border to repair 2 chassis that had collapsed.  Plant installed the wrong frame beams.  2 day job.I have worked around welding for 45 years now, and learn every day.  I long ago developed my own techniques to counter distortion, alignment, etc.  Because welds shrink when cooling, I use it to my advantage.  If I'm do a 90 degree type weld, say with tubing, I'll position the one tube a little off the 90 and let the shrinking weld pull it to the 90.  If doing something like the original poster did, I'll use blocks and C clamps to create a camber then weld the heavy block, release the C clamps for a straight tube.  Sometimes I need to do a little tweaking to get it perfect, but not too often.A tip.  When welding 2 pieces of sheet metal, in a butt joint, to help prevent distortion, usethe "back step" method.  Run a short bead say about 1" from the end back to the end,  Next weld, go 1" further, and then BACK to the first bead, and so on.  It ain't perfect, but sure helps with warping.