How to straighten cast ali
Discussion
After friday afternoon's entertainment of a dick in a volvo trying to ram me into a lorry as I filtered past I now need to repair the pillion peg hanger. It got caught under the volvo's arch & has bent down so the peg is at about 45 degrees.
Anyone know how to do it? I think you heat it (till red?) quench, hammer & repeat. Doing a small bit at a time because it case hardens & will shatter.
Anyone know how to do it? I think you heat it (till red?) quench, hammer & repeat. Doing a small bit at a time because it case hardens & will shatter.
I wouldn't heat, quench hammer... that will snap it. Chances are it will snap but heat and bending might work. What have you got to lose.
Watch this too : https://www.youtube.com/watch?v=8-aNNYo24RU
Watch this too : https://www.youtube.com/watch?v=8-aNNYo24RU
Edited by Mort on Monday 6th July 13:33
Problem is the hanger will be of a very low quality aluminium alloy which is cast and with a very low malleability . So typically once it's bent, it won't return to shape regardless of how or what process you employ. Having stretched in the bending, the alloy is now weakened and can't be manipulated back. It'll fracture and snap if you try to reshape it either during the process or worse, later when it's subjected to stress like when it's taking someone's weight.
You'll need to be replacing it sadly...
You'll need to be replacing it sadly...
Hooli said:
Bugger arse n bks then.
I might try it for the hell of it anyway then pay out for a new one.
Try to manipulate it in a 10 tonne press if you can get to one. heat it in the oven and give it a small amount of pressure until it cools.I might try it for the hell of it anyway then pay out for a new one.
Heat and repeat.
Are there lateral stress lines at the point of the bend? like little hair line cracks running across the outer surface of the bend? Or raised material like a fold on the inside of the bend?
There is also the soot method for heating cast aluminium where you coat it with soot from a dirty acetylene flame, then heat with a clean flame until the soot starts to burn off. Then bend. But it depends very much on the alloy in question. I'm betting it's a low grade alloy with a very granular property which won't bend back.
Also remember that in being bent, it has been work hardened, so it's structure at the bend will have changed..
Edited by bass gt3 on Monday 6th July 14:31
bass gt3 said:
I'm betting it's a low grade alloy with a very granular property which won't bend back.
Also remember that in being bent, it has been work hardened, so it's structure at the bend will have changed..
Aye. It might go back to something approaching shape but I wouldn't want to use it as a load-bearing component.Also remember that in being bent, it has been work hardened, so it's structure at the bend will have changed..
I work in NDT; would you like it x-rayed, MPI'd or dye pen'ed? Although I suspect we could write the report without even seeing the part
Wedg1e said:
Aye. It might go back to something approaching shape but I wouldn't want to use it as a load-bearing component.
I work in NDT; would you like it x-rayed, MPI'd or dye pen'ed? Although I suspect we could write the report without even seeing the part
MPI wouldn't be much use on an Alloy would it?!I work in NDT; would you like it x-rayed, MPI'd or dye pen'ed? Although I suspect we could write the report without even seeing the part
Agreed about not using it again though. Even if you could put it back into shape you'll regret it if it snaps whilst cornering etc
Buy a new one.
Hooli said:
Topic over girls.
I've discovered that foot pegs hangers are listed on ebay as footrests. Found one for £20, which is reasonable so I ordered it.
PS. I like the idea about heating until runny & pouring in a mould, I'll have a spare to shape the sand with now...
Well there's no fun in that! I've discovered that foot pegs hangers are listed on ebay as footrests. Found one for £20, which is reasonable so I ordered it.
PS. I like the idea about heating until runny & pouring in a mould, I'll have a spare to shape the sand with now...
evil len said:
southgate said:
Mort said:
I wouldn't heat, quench hammer... that will snap it. Chances are it will snap but heat and bending might work. What have you got to loose.
Your pillion? My luggage would be closer, I hardly ever have a pillion but the pannier racks attach to the pillion pegs when fitted.
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