Newbee needs some help

So I welded a pair of 1/4" plates to fashion a door for my potato locker. I used 2" channel around the perimeter of the door. Door then 2.5" which is good for deadbolt.

Got all done and there is a 5/8" bow from top to bottom. I am looking for advice on how to straighten.
I have a pair of 8' I beams on order for another project that I could conscript into this effort. I am thinking some very large C clamps on each corner might provide enough coaxing. Maybe a little heat from the torch.
Am I dreaming?
Reply to
PowerSupplyGuy
Loading thread data ...
Disclaimer - these people working in steel fabrications companies vastly more street-wise than me about these things. Anyway...
There is "flame straightening". Look it up. No mechanical effort - all in use of heat.
Force alone - possible. You might have to add packers to force a "reverse bow" to force yield in the opposite direction, so on releasing the clamps its bounce-back is to straight.
Clamping to something strong and stiff while welding is a good strategy. Restraint the weld while it's cooling and would distort in the first instance... Make sure your clamps are strong enough though - weld distortion forces can be very high - you often meet hopelessly twisted clamps in a FabCo.
Rich S
Reply to
Richard Smith
Thanks Rich. I remember when I was a kid learning auto body - Had to quench the panels with a wet rag so they would go back to where they belonged. I was the rust guy and had to braze that crap. Nasty job. Ok. I will go look for flame straightening.
Thanks, Bob
Reply to
PowerSupplyGuy
Hydraulic jacks work if you can figure out how to rig them up safely; so you don't create a giant crossbow that fires if anything slips. No clamp I own was strong enough to straighten salvaged 3" x 8' channel iron but a 4 ton porta-power-type ram easily straightened it well enough to use as sawmill track.
Reply to
Jim Wilkins
Thank you Richard. I will attack the door on Saturday with a bottle jack and see what I can do.
Reply to
PowerSupplyGuy
Thanks Jim. I'll try the bottle jack. I've got a large H-beam showing up tomorrow for my next project so I can probably set it up on that.
Reply to
PowerSupplyGuy
Since it's on a potato locker, appearance can't be too important - so you could just live with it. Some fiddling required to get the hinges right, but fiddling is easier than trying to bend a 2-1/2" deep, 36" wide(?), 1/4" skinned box. That's one strong element.
Bob
Reply to
Bob Engelhardt
Yes, the potato locker door has proven itself to be a worthy opponent. The hinge side wasn't welded up so that it was fairly easy to get straight. The 4 hinges look like they are aligned ok.
I have a 20 ton jack and I'll give it another shot this weekend.
Reply to
PowerSupplyGuy
Good Call Rich. I applied a little counter-bend with a 22 ton bottle jack and some chain. Heated up some dollar-size spots till it glowed and shined a hose on it. Got it straight in no time. Good lesson to learn. Thanks.
Reply to
PowerSupplyGuy
Glad it worked. That's really made my day! I was a bit tentative, seeing as I didn't see myself as having the depth of practical experience to speak with confidence. Rich S
Reply to
Richard Smith

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.