flame-straightening

[foy9999]

So I want to give this a try with my oxy-acetylene gear

Essentially you heat spots on the wide side of the bent metal and when the spots cool and contract it pulls the metal straight.

Sounds to good to be true but in the USA they use the technique to straighten-out crash-damaged bridges so I have some confidence it might straighten out lots of motorcycle parts I have (shallow bend in frame down-tube, bent centre-stands, bent pedal shafts etc etc)

Anyway. I got started tonight: #10 nozzle, both gasses at about .3 Bar. the metal glowed red quickly and I let it cool then did it again but am not sure how quick it should move.

Will it be like 1mm every 10 spots?

 

[Brad93]

So I want to give this a try with my oxy-acetylene gear

Essentially you heat spots on the wide side of the bent metal and when the spots cool and contract it pulls the metal straight.

Sounds to good to be true but in the USA they use the technique to straighten-out crash-damaged bridges so I have some confidence it might straighten out lots of motorcycle parts I have (shallow bend in frame down-tube, bent centre-stands, bent pedal shafts etc etc)

Anyway. I got started tonight: #10 nozzle, both gasses at about .3 Bar. the metal glowed red quickly and I let it cool then did it again but am not sure how quick it should move.

Will it be like 1mm every 10 spots?

Youtube, AGA Gas do a very good video.

You won't get any movement heating the frame unless there is a force to oppose the expansion of the material.

Sometimes the weight of the component or internal stresses alone is enough. With thin tube it doesn't work like that. You need to apply a restriction to cause a plastic deformation.

 

[zzr1200]

Youtube, AGA Gas do a very good video.

You won't get any movement heating the frame unless there is a force to oppose the expansion of the material.

Sometimes the weight of the component or internal stresses alone is enough. With thin tube it doesn't work like that. You need to apply a restriction to cause a plastic deformation.

I tried searching for AGA Gas on YT, lots of nice AGA Gas cookers, I didn't find any videos on straightening metal?...........

A YT link maybe....please..

 

[addjunkie]

Ive seen it done on a big pump shaft, moves minute amounts.

Think your expecting a bit much with out helping it move once hot.

 

[voipio]

Vice and BFH? Or a hydraulic press and appropriate tooling?

 

[Woody.v8]

I've seen Keith fenner on his YouTube channel flame straightening shafts, he heats then quenches with comprssed air/water.

 

[Misterg]

Alan Millyard straightening a camshaft here:

 

[Welderpaul]

I've seen Keith fenner on his YouTube channel flame straightening shafts, he heats then quenches with comprssed air/water.

He’s a very knowledgeable fella but the amount of times I’ve dozed off listening to him.

 

[fizzy]

He’s a very knowledgeable fella but the amount of times I’ve dozed off listening to him.

He does have rather a strange persona

 

[Seadog]

He’s a very knowledgeable fella but the amount of times I’ve dozed off listening to him.

I gave up watching him some time ago. Not long after his saluting the flag and his divorce began.
He is very skilled, though. His earlier videos are definitely worth watching.

 

[Pond frog]

 

[Pond frog]

That was meant be the AGA video not sure why it’s unavailable as I can get it on YouTube, I’ve had it saved as one of my favourites for years

 

[Misterg]

That was meant be the AGA video not sure why it’s unavailable as I can get it on YouTube, I’ve had it saved as one of my favourites for years

The owner probably doesn't allow embedding.

Click this instead

Good video - I watched it a while ago after seeing another video of someone straightening a very bent girder in a bridge.

 

[foy9999]

Ive seen it done on a big pump shaft, moves minute amounts.

Think your expecting a bit much with out helping it move once hot.

I can help it along but the point of the process is supposed to be to avoid that so you don't crease the metal

 

[foy9999]

Alan Millyard straightening a camshaft here:

amazing. He makes it look so easy

 

[Morrisman]

I’ve straightened a few rear axle housings, that I’ve bent by welding brackets to them. Heat alone doesn’t really do the job, so a couple of lines of hot weld are used. It works quite well.

 

[Robotstar5]

I’ve straightened a few rear axle housings, that I’ve bent by welding brackets to them. Heat alone doesn’t really do the job, so a couple of lines of hot weld are used. It works quite well.

I put a welding robot in for a company that made sidesteps for 4x4's, some of them had a run of weld down the back purely to staighten them back out.

 

[Morris]

When I worked at King Trailers in t e 80's we would regularly straighten very large beams and fabrications with a rosebud torch (a BIG one) and a crude spraygun type thingy that used air and sucked water out of a bucket. Some of the beams could be 20" deep (and even bigger).

 

[Morrisman]

I’ve seen videos of ship building in Japan years ago, guys bending and curving inches thick steel plates, using nothing but massive blow torches and water. Complex compound curves etc. Even after watching I have no idea how they did it, I think it was a secret dying art.

 

[Seadog]

https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://m.youtube.com/watch%3Fv%3DIxzV9VeUpLY&ved=2ahUKEwjFzZW2zbaJAxUMXUEAHZNOPSQQwqsBegQIERAG&usg=AOvVaw0FZBgbHdnMeXEsV_kVuOvs