how to straighten out warped steel bar?

[dstig1]

You should be able to generate enough heat with a large propane torch, as long as you keep it in one spot long enough. After all, people use propane burners for backyard foundry set ups...

 

[gerard]

I'd go for the tree and jack method.
1. The metal isn't that far out of whack
2. A 6 ton should bend it with no problem
3. You can adjust it easily for the "springback" issue
4. It ALREADY fits so we're just talking aesthetics here
5. Handling it after you make it red hot is not going to be easy without tongs, chain falls etc.

 

[Hooked_on_HP]

Where did you get the teeth for your tooth bar.
Bill

 

[tcreeley]

All you guys are great.....I should have made a dozen ugly warped toothbars to keep me going at all the suggestions ... (except barbecueing the thing on the grill...couldn't explain to wife).

1 - jury-rig up a bending kluge, using a tree, a wide square 2" board to protect the tree, some plate, two bottle jacks, a couple of 6x6 wood blocks, some clamps, some hardened chains, and maybe the winch.....and s-l-o-w-l-y reverse-bend the thing until it either complies, breaks, or accomplishes nothing. (pics to follow).

2 - - I'll cross line-score the bottom of the bar at the existing weld points as per bxpanded's suggestion (he makes great & solid accessories, which means he knows stuff) ..... then weld a bunch of mig wire cross-wise onto the bottom, at each shank point, one at a time until each section gets dull red, and see if it shrinks to compensate for the existing warp......and then grind through a few discs worth to get the repair weld off.
...

I think you may run into trouble with 1. You may but a bend in the mild steel that you can't get out. It warped because one side of the steel shrank and the other side expanded. Maybe #2 could reverse that.

I like to use a 3 lb hammer for this stuff and hammer it between the teeth over a piece of steel on top of a cinder block or thick chunk of wood. (anvil is best). Like someone else said - put some small 1/8, 1/4 flat stock between each set of teeth and hammer midway between. You're actually trying to bend the steel by hammering. Do this for every set of teeth. Start in the middle of your tooth bar and work out. On an anvil this would be easy. Over a coal forge it would be even easier- without heat warp! If you can use a mig welder, a o/a torch is a piece of cake and with some of the bigger tips- it can heat areas for accurate bends, especially when you use it with a vice.
Mild steel is pretty forgiving. Not much temper.
Good luck.

 

[castiman]

In your first post you said that you just finished your first project, if your planing more welding projects in the future I would really consider buying or renting a O/A setup. I assume that you taught yourself how to weld and with alittle practice you'll learn how to use that too. It's a tool your going to need.As for straighting this tooth bar,my suggestion is, you say it fits then until you can put some real heat on it I would bolt it on even if you have to add another hole in it to draw it down. After it's bolted on then put heat to it and let it set and cool down. Just make sure that you have some gap on both ends of the tooth bar so you can pull it straight out.I also think your asking for trouble trying to straighten it out by hitting it or using jacks. Heat caused it to bend and heat will straighten it out.

 

[CT Jay]

Got the teeth, shanks, pins, from my local tractor dealer where I bought my Kubota BX25.......Westchester Tractor, Brewster, NY......they had them in all sizes, on racks on the showroom floor by the parts dept.

Bought 5 shanks, 5 teeth, 5 pins, in the size I measured to best fit my need.

Shanks made by CNH. Teeth by ITR. No idea who those companies are. Side pin style (as opposed to "top pin" or "crimp-on". Size of parts listed as "23", but I don't know what that refers to.

Shanks cost me $13.48 each.
Teeth cost $7.50 ea
Pins (2 piece steel with compressible rubber between) cost $2.84 ea

Total for all came to $119.10 + tax, and that's dealer parts stock retail price. You might do better online, but I didn't know what I needed and wanted to see-handle-measure-heft the stuff myself.

I had some grinding to do on the shanks to get the gaps to sit flat & flush on the bar, but no big deal.

These shanks are called "wrap around" style, designed to sit with most of the meat on top of the bar (or bucket, which they're primarily intended to be for most people). There's also "bottom leg" shanks, if you want the long side to fit under the bar, not on top.

I don't think you'll find this stuff at T/S....at least, not at my local store. I looked there first.

Check at your local tractor dealer......or search the forum under "toothbar"...I recall seeing posts with names and links of parts suppliers that sell teeth, shanks, etc. Lots of guys build them. I saw one bar in particular that "tach driver" had built and posted pics. His work was great, and gave me the idea to try same.

Online, check out Fabco Inc. They have charts, sizes, etc online, and all kinds of shanks & teeth to confuse the **** out of you until you figure out what you need.

 

[The Haymaker]

Maybe it has been mentioned, don't have time to flip through all the posts, and hindsight is 20/20. Clamp the piece down securely on your next project and this won't happen.

 

[CT Jay]

OK, I see that T/S sells a little O/A tote kit.....

Oxy Acetylene Welding and Cutting Tote Outfit with Cylinders - 3862540 | Tractor Supply Company

2 small cylinders.....20 CF O2.....10 CF Acetelyne....plus basic accessories.

Would this be a waste of time, with bottles that small, for light occasional use? Would I run out of gas and have to refill/exchange by the time I barely start using the thing?

 

[rjmack]

Would this be a waste of time, with bottles that small, for light occasional use? Would I run out of gas and have to refill/exchange by the time I barely start using the thing?

it never hurts to have an oxy/acetylene setup... all the same, i would get much larger bottles.

for what you have to do... forget preheat or hammering... just use force, slow and steady.

anchor the piece to a solid table/bench/truck/put it between two trees... use anything that you have... and use the bucket of your tractor to exert pressure upward/downward/forward/backward... whatever.

___\|/___\|/___\|/___\|/___ etc. the flatbar is bent from the weld at each tooth, apply pressure to each tooth progressively from one end to the other. you don't need heat for something that light, and hammering it will just make a bigger mess. put two 2x4's on the ground, lay the piece across it and back your tractor on top of it... there must be a million easy solutions.

you have probably spent more time asking how to do it than it would take to effect the repairs.

no offense, but this is pretty simple... just bend it back straight.

 

[CT Jay]

Fixed. Straight as a line now. Slides right onto FEL. No more hammering.

Welded onto bottom side of bar, at appropriate places, to generate heat, which straightened it out....then ground off the weld.

Paint next.

Thanks to everyone, particularly Shield Arc, for the many suggestions. Lots of ways that would have fixed this, I see from all the helpful posts, but I had to pick one, and I chose the method that gave me some more welding practice, even though doing it this way was probably the most time consuming, by far.

Next project I'll have a better idea of what to do to minimize heat warp.