I have a bent support bracket on a backhoe bucket and it needs some serious heating to bend it back to fit the dipper arm. I'm thinking of piling on some charcoal and rigging up a hair dryer as a blower to bring the heat up on this beast enough to bend the support out so it will fit. Suggestions, ideas, comments?
If the bend is slight you may be able to flame shrink the opposite side so that the metal drawing together as it cools straightens it. A rosebud torch works good for that. You will probably have to do it several times, in slightly different spots to get the desired effect.
Not sure exactly WHAT is bent and how big, but your problem sounds like it won't be that you can't heat it, but that the heat you are applying gets away too quick due to the metal mass and temperature differential. The charcoal pile would help here, but leaves a lot of exposed surface. Is there any chance of using a pile of very dry sand to bury all but the part you want to get hot with a rosebud? Keeps the heat from being carried away by the surrounding metal. Maybe you can't work with it if you do that, but assuming it is worth a try, how about setting up hydraulic jacks ready to ":push" on it, or come-a-longs to "pull" it when it gets hot enough?
"Kitty Litter" or Zorb-All works very well too, but not heavy enough to hold this thing in place for serious bending, and more costly than sand, which I assume you have access to if you do back-hoe work.
Take care. Good Luck. Pix is always nice!!
Brian Laws>I have a bent support bracket on a backhoe bucket and it needs some
Suggestions, ideas, comments? ^^^^^^^^^^^^^^^^ A BIG pile of charcoal, along with two or three hair dryers, AND a large rosebud tip to raise the temperature a little more after the charcoal has done all it can.
Be sure to have all the bending setup in place before you start. You don't want it to be cooling while you look for a suitable monkey wrench to grip it with ;-)
Good ideas, thanks. I'm not near the "hoe" or I would get you a picture. The part that is bent is one of the plates that mount to the dipper. One is bent inward so that the dipper doesn't clear enough to push the pin through.
Thanks. I don't have a rosebud torch tip so I used the largest cutting torch tip I have. (I didn't try the cutting jet until I could slowly move in on the heated area to avoid actually cutting the steel. It still took a lot of heat and didn't ever get to cherry red. At the end of this I whacked on the plate with an eight pound sledge but it didn't make any observable movement. Then I remembered David Gingery's charcoal forge idea and thought I would try a variation on this idea.
Perhaps this is a silly idea, so think it through before you do anything, but perhaps you could use the backhoe itself to bend the plate? If you lay the bucket on its side and figure out a means of securing it to the ground (put a big rock on top of it or something), then fit another bucket to the backhoe and get the teeth under the bent plate, you may be able to pull it upwards. There are probably a good few variations on this idea, and to make it work you would need a strong and controllable backhoe, but it's a thought. I also thought of putting a bottle jack between the two plates, but the danger is that you will bend the undamaged plate. Maybe you can think of a variation on these ideas which will work?
One possibility, depending on the extent of the bend, is to use a big stick welder to run a bead with a large-diameter electrode, offering you two things - the differential shrinkage pulling in the direction you want it to (which might be enough to cure a small bend), and a substantial amount of heat in the metal when you apply your bending force to push it where you want to go. That would also leave the other plate unheated (or only as hot as the pre-heat it got), so you could use the other plate to push on without being as likely to bend the other plate the opposite direction.
Pre-heating the whole thing with your charcoal might still be a good idea, and will increase the working time from the additional heat of welding on it. Likely want post-heat or lo-hy or both to avoid having much likelihood of increasing the odds for bad things involving cracks to happen later on.
On Fri, 11 Nov 2005 12:35:09 -0600, with neither quill nor qualm, Mike Slowey quickly quoth:
Heat plus a porta-power ought to straighten that out quickly. Charcoals lined up in a v-shaped brick trough might work.
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Sound like jack time to me. With or without heat depending on how big it is. On really big track hoe buckets I've had to resort to cutting it off and rewelding it to get it right.
But if it's a standard back hoe bucket a good hydraulic jack 20-50 ton capacity can probably bend it back depending on how the bucket is made and where it's bent. Just use a good sized piece of pipe for the base of the jack so that it goes down to the corner of the side that's not bent (that way you don't bend it out). A piece of plate tacked to the top of the pipe for the jack to sit on and put the ram of the jack out as far as you can on the bent side. When placing the jack be sure to put the pump on the bottom (yes hydraulic jacks will work sideways as long as the pump is on the bottom). You may need a piece of plate tacked to the bent side if you have to press near the outside of the hole. Otherwise it might just bend at the hole and not at the base.
If it's to small for a jack to fit in then there is a few other alternatives the best is a porta power but even a good sized piece of threaded rod and a nut can be used to put a lot of force on something.
Mike Slowey wrote in news: firstname.lastname@example.org:
Use what you've got. A couple of plates/rocks and the backhoe boom. Put the pivot pin in the boom before you do this, but lay the plate between two supports and tap it with the boom end. Nothing like a good 2 ton hammer to bend a tie plate. (Been there, done that, got the shirt.)
could you use one of those "scorcher torches"? ("weed burner" "roofing torch") i think it's like 500,000 btu's and it seems like it would be a more controllable focusable heat source, i must admit though i haven't yet used it on a metalworking project (but intend to try it soon, want to see if i can use it to heat and twist a 1"x1" solid steel bar). propane is cheap enough (cheaper than acetylene/rosebud). or, even, use two torches, one on each side of the bracket? i got a cheapy "scorcher torch" from Harbor Freight and i sent it back, faulty manufacturing, but they're cheap from HF and maybe you'd get lucky and get one that didn't fall apart in your hands. i got a better quality one on-line somewhere, i think it was about $50. among the various other things i've used it for, one of the projects was flaking off the top 6 inches of a (huge immovable) boulder that was protruding from the middle of a dirt road/driveway.
this is the one i got, i believe i ordered it on line but found out soon after it arrived i could've purchased it from my local welding supply store at nearly the same price.
don't know for sure if it would work on your application. i do know if you get the nozzle too close to the work the torch "flames out", it can be a pain in the ass.
| > I have a bent support bracket on a backhoe bucket and it needs some | > serious heating to bend it back to fit the dipper arm. I'm thinking of | > piling on some charcoal and rigging up a hair dryer as a blower to bring | > the heat up on this beast enough to bend the support out so it will fit. | > Suggestions, ideas, comments? | >
| > Thanks in advance. | > Mike
Would a couple-few really heavy stick weld beads on the outside of the bend pull it back in for you some, or is it bent too far?
Those torches well help but in my experience won't put out enough heat to do the job by them selves. However having one on the back side feeding heat into the piece while using a rose bud (or large cutting tip) on the front may put enough heat in to do the job.
Remember that the most heat isn't inside the flame but just at the edge of the flame.
That one has the same fault the HF cheapie has - the single needle valve. It's too easy for you to miss the 'pilot' setting and go right to 'Off' when just trying to turn it down for a minute. Then you have to get out the lighter again.
The good one from Harbor Fright is okay, the one with the 'pilot' needle valve and the squeeze trigger valve for high flow. It's actually Italian, not Chinese, IIRC. If you don't plan on using it all day every day it should work fine.
It flamed out because you interrupted the venturi flow of gases through the weed-burner torch - you have to keep it a few inches back from the surface to be heated.
The big barrel of the torch is a mixing chamber where the propane stream through the orifice mixes with and pushes the air through the venturi. Most of the flame is happening out past the venturi tube, or you'd soon melt the outer venturi tube.
And in this case, a few inches in front of the burner barrel.