Page 1 of 2 12 LastLast
Results 1 to 25 of 39

Thread: Straightening a weldment

  1. #1
    Join Date
    Mar 2018
    Posts
    76
    Post Thanks / Like

    Straightening a weldment

    Iím building some material racks out of 2x1/8 angle. As expected, they have quite a bow from welding:


    As I understand it, heat straightening would be the best approach? I donít have a torch but in theory could get a oxy-propane setup.

    Is it worth trying to straighten these using a 20T press? It seems like it might work.

    If you were heat straightening, would you heat the areas I highlighted in yellow? Or those in pink? Or somewhere else?


    And am I correct that the process is to heat to orange hot then cool with sprayed water?

    Thanks for any advice,
    Jason

  2. #2
    Join Date
    Aug 2018
    Location
    'ta town, KS
    Posts
    211
    Post Thanks / Like

    Re: Straightening a weldment

    If you spray it with wat6it will crystallize the structure of the steel making it harder yet weaker. As hard breaks soft wears.

    Sent from my SM-G960U using Tapatalk
    I haven't built anything I can't throw away. Perfection is the journey.

    Mac

  3. #3
    Join Date
    Oct 2015
    Posts
    2,603
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by Mac's Crew View Post
    If you spray it with wat6it will crystallize the structure of the steel making it harder yet weaker. As hard breaks soft wears.

    Sent from my SM-G960U using Tapatalk
    Heat the area you have marked in pink. Then use a cold wed rag to quench the area. Watch the piece as it straightens and stop quenching when it is straight. It will take a couple of times to get the process down but after that it will go fast. Experiment with the amount you heat it too.

    The heated area will expand when it is hot and will make the bend worse while it is hot but the quenching will shrink the steel back down and straighten the piece.

  4. #4
    Join Date
    Dec 2018
    Location
    Southern California
    Posts
    742
    Post Thanks / Like

    Re: Straightening a weldment

    If you don't have a torch or press, just match every weld (with another weld) on the opposite side of the bowed angle iron (to balance the shrink forces) and then grind them down (or don't).

    Match every weld and then you can go back and add more weld (shrink) if needed. Easy, and time consuming, but a torch setup is ~$300, a hydraulic press is ~$150 and takes up quite a bit of room.

    Since your racks look straight in one dimension i would heat in the purple areas, but only on the bowed side (not the triangular bit on the "top" side in the pic). If it is bowed in both dimensions then heat both sides to straighten in two directions (up and to the right in orientation to the colored "where to heat" pic).
    Last edited by SlowBlues; 04-11-2020 at 02:57 PM.

  5. #5
    Join Date
    Aug 2014
    Location
    B.C. Canada
    Posts
    2,229
    Post Thanks / Like

    Re: Straightening a weldment

    And be patient. It might get worse before it gets better. And when things start going the way you want, DONíT get greedy. Take slow steps and try to remember what works and what doesnít.

    Youíll get it. Have fun!
    :

  6. Likes 12V71 liked this post
  7. #6
    Join Date
    Oct 2006
    Location
    Illinois
    Posts
    9,310
    Post Thanks / Like

    Re: Straightening a weldment

    What is this getting mounted too. ??


    Sent from my iPhone using Tapatalk

  8. #7
    Join Date
    Nov 2005
    Location
    Nashville, TN
    Posts
    3,628
    Post Thanks / Like

    Re: Straightening a weldment

    In this case I would Bend it cold. Concentrate the bending force on the flange. Angle likes to twist. You could also weld a bead opposite the welds.

    However, you do it, patience is important. With heat /water or welding, stop and wait until the bending action stops. The contraction is creating the results and it is always greater than the expansion.

  9. #8
    Join Date
    May 2014
    Location
    Central Wa. state
    Posts
    3,215
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by Lis2323 View Post
    And be patient. It might get worse before it gets better. And when things start going the way you want, DON’T get greedy. Take slow steps and try to remember what works and what doesn’t.

    You’ll get it. Have fun!
    This, exactly. Shrinking is hard to undo. And it will happen faster than you think.

  10. Likes ronsii liked this post
  11. #9
    Join Date
    Mar 2011
    Location
    Western Washington
    Posts
    6,312
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by 12V71 View Post
    This, exactly. Shrinking is hard to undo. And it will happen faster than you think.
    LOL!!! Ain't that the truth

  12. Likes 12V71 liked this post
  13. #10
    Join Date
    Feb 2019
    Location
    Snyder TX
    Posts
    64
    Post Thanks / Like

    Re: Straightening a weldment

    To straighten it cold, you can set it on top of a hydraulic jack on your table. Center of bend. Chain each end to the table, jack it past true & let pressure off to check it. It may have to go an inch or two past true to make it relax back straight.

  14. #11
    Join Date
    May 2014
    Location
    Central Wa. state
    Posts
    3,215
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by ronsii View Post
    LOL!!! Ain't that the truth
    On a serious note I do quite a bit of flame straightening. Here's a pic of some from last year. This was the startpoint.Name:  20180115_133824.jpg
Views: 370
Size:  88.7 KBName:  20181129_134530.jpg
Views: 370
Size:  99.6 KB
    The second pic is almost there, still needed some re-arching when I was done with getting it straight enough to track down the road.
    Last edited by 12V71; 04-11-2020 at 06:14 PM.

  15. Likes ronsii liked this post
  16. #12
    Join Date
    Oct 2014
    Posts
    2,019
    Post Thanks / Like

    Re: Straightening a weldment

    Do you have some strong Bessey clamps or C clamps? Maybe you could put them back to back with 2x4's or 4x4's in the middle and use clamps at the ends to try and straighten them out some. Will have to go a little more than required. This would be relatively inexpensive to try. If the racks are bolting on a wall will probably straighten out when bolting on.

  17. Likes tapwelder liked this post
  18. #13
    Join Date
    Apr 2010
    Posts
    2,622
    Post Thanks / Like

    Re: Straightening a weldment


    12V71


    Quote Originally Posted by 12V71 View Post
    Here's a pic of some from last year.
    Any idea of what caused the deformation . . . ?


    Opus

  19. #14
    Join Date
    May 2014
    Location
    Central Wa. state
    Posts
    3,215
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by OPUS FERRO View Post

    12V71




    Any idea of what caused the deformation . . . ?


    Opus
    It had something heavy dropped on the right hand side (as sitting in the drivers seat) there were a couple of buckled spots in the top flange that were trimmed out and replaced after things were straightened out. The current owner bought it like that and ran it several years that way. I only suggested straightening it when I had to re deck the thing.

  20. #15
    Join Date
    Mar 2018
    Posts
    76
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by BD1 View Post
    What is this getting mounted to?
    To a 2x6 wall, with tabs that I will weld on to each bracket.

    Quote Originally Posted by tapwelder View Post
    In this case I would Bend it cold. Concentrate the bending force on the flange. Angle likes to twist. You could also weld a bead opposite the welds.
    Quote Originally Posted by cwby View Post
    To straighten it cold, you can set it on top of a hydraulic jack on your table. Center of bend. Chain each end to the table, jack it past true & let pressure off to check it. It may have to go an inch or two past true to make it relax back straight.
    Quote Originally Posted by Welder Dave View Post
    Do you have some strong Bessey clamps or C clamps? Maybe you could put them back to back with 2x4's or 4x4's in the middle and use clamps at the ends to try and straighten them out some. Will have to go a little more than required. This would be relatively inexpensive to try. If the racks are bolting on a wall will probably straighten out when bolting on.

    Thanks I have a press itís just an awkward shape to fit in there. These are some helpful ideas on how to get around that. I appreciate the help.

    Quote Originally Posted by SlowBlues View Post
    If you don't have a torch or press, just match every weld (with another weld) on the opposite side of the bowed angle iron (to balance the shrink forces) and then grind them down (or don't).
    I thought about this too, thanks. Iíll try some mechanical methods first and then maybe some additional beads.

    Quote Originally Posted by Lis2323 View Post
    And be patient. It might get worse before it gets better. And when things start going the way you want, DONíT get greedy. Take slow steps and try to remember what works and what doesnít.

    Youíll get it. Have fun!
    I appreciate the encouragement and useful guidance. I knew before I fíed it up I should ask people who have done it. I was kind of hoping the only solution was to buy a torch and oxygen tank (it would be about time) but Iíll give the mechanical methods a go first. Thanks all. Iíll report back.

  21. #16
    Join Date
    Mar 2018
    Posts
    76
    Post Thanks / Like

    Re: Straightening a weldment

    I first tried some clamps on my table but it seemed pretty hard to move the metal:


    So I built a frame to support my weldment at two points and hold it from twisting:


    I overdid it a bit on the first two but the third came out pretty straight:

  22. Likes Lis2323, Dee_veloper liked this post
  23. #17
    Join Date
    Oct 2014
    Posts
    2,019
    Post Thanks / Like

    Re: Straightening a weldment

    Glad it worked. How many pounds are your clamps rated for?

  24. #18
    Join Date
    Jan 2020
    Posts
    17
    Post Thanks / Like

    Re: Straightening a weldment

    That's pretty impressive, it can be pretty tough to get a warped angle that straight. Looks great

    Sent from my SM-G970W using Tapatalk

  25. #19
    Join Date
    Oct 2006
    Location
    Illinois
    Posts
    9,310
    Post Thanks / Like

    Re: Straightening a weldment

    Glad you got it straightened out.
    You do know what caused that right ?
    So it will be avoided on future projects .


    Sent from my iPhone using Tapatalk

  26. #20
    Join Date
    Jun 2012
    Location
    Ct
    Posts
    2,365
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by SlowBlues View Post
    If you don't have a torch or press, just match every weld (with another weld) on the opposite side of the bowed angle iron (to balance the shrink forces) and then grind them down (or don't).

    Match every weld and then you can go back and add more weld (shrink) if needed. Easy, and time consuming, but a torch setup is ~$300, a hydraulic press is ~$150 and takes up quite a bit of room.

    Since your racks look straight in one dimension i would heat in the purple areas, but only on the bowed side (not the triangular bit on the "top" side in the pic). If it is bowed in both dimensions then heat both sides to straighten in two directions (up and to the right in orientation to the colored "where to heat" pic).
    I was about to say this, but you beat me to it, this is the way to do it.
    I did some stainless steel fabrication with 2x2 tubing, the way it was laid out made it warp, I had to weld on the opposite side to straighten it out, it works fast too,

  27. #21
    Join Date
    Mar 2018
    Posts
    76
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by Welder Dave View Post
    Glad it worked. How many pounds are your clamps rated for?
    The big one is 2000 lb according to Kant Twist. It felt like I was going to have an easier time with the press so I went with that.


    Quote Originally Posted by BD1 View Post
    Glad you got it straightened out.
    You do know what caused that right ?
    So it will be avoided on future projects.
    Well, I thought it was inherent to welding on one side of the long piece. Iíd love to hear more about how to avoid it.

  28. #22
    Join Date
    Aug 2014
    Location
    B.C. Canada
    Posts
    2,229
    Post Thanks / Like

    Re: Straightening a weldment

    Clamping it down securely and taking your time with the welds allowing them to cool will help. Skip around also. Do one leg near an end and then perhaps one halfway up the length. Donít do them consecutively.
    :

  29. Likes ronsii liked this post
  30. #23
    Join Date
    Oct 2014
    Posts
    2,019
    Post Thanks / Like

    Re: Straightening a weldment

    Being it's only 1/8" it will warp much easier with enough weld for 1/2" thick material. I think your racks could be bent into pretzel shapes before they broke. Clamping them back to back when welding them would help and like said above don't weld one section all at once.

  31. #24
    Join Date
    Jul 2008
    Posts
    2,431
    Post Thanks / Like

    Re: Straightening a weldment

    Quote Originally Posted by Lis2323 View Post
    Clamping it down securely and taking your time with the welds allowing them to cool will help. Skip around also. Do one leg near an end and then perhaps one halfway up the length. Donít do them consecutively.
    Also, welding hotter so you can get in and get out faster (with less total heat input) can help, too.

  32. Likes Lis2323 liked this post
  33. #25
    Join Date
    Aug 2014
    Location
    B.C. Canada
    Posts
    2,229
    Post Thanks / Like

    Re: Straightening a weldment

    I have often wondered for welding smaller heat critical projects if something like this would work to minimize distortion.




    Obviously if it worked it may not be cost effective on bigger jobs but has anyone ever tried something similar?
    :

  34. Likes ronsii liked this post

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Page generated in 1,593,959,260.78491 seconds with 15 queries