flame-straightening

[Beeezer]

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).

King trailers… in the 80s..
I was at Towrite Fabrications in the late 80s

 

[Misterg]

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

This was the video - flame straightening a huge girder after it was hit by an over-height load. It's like magic.

(It's an old video, so the quality is a bit ropey, but the content is fascinating):

 

[Morris]

King trailers… in the 80s..
I was at Towrite Fabrications in the late 80s

Small world. Are you still local?

 

[roofman]

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.

Yea i stopped watching when his divorce started too...his content changed too and i just became un-intrersted

 

[Beeezer]

Small world. Are you still local?

Yes very.

 

[foy9999]

So. So I gathered together all the bent stuff I've had for years and started putting penny-sized hot-spots on them with the torch. I went down from the #10 nozzle to the #5 and it still seemed like plenty heat.

After several goes on several bits I can say I saw no straightening so tried cooling things more rapidly with cold water and still nothing.

I will keep trying till my gases run out

fwiw the items are:

• Yamaha RD125 swing-arm with bent front lugs (due to someone trying to push Metalastik bushes from it on a press)
• Yamaha CS3 centre-stand bent and creased (possibly due to someone sitting on the bike on its stand)
• Honda SS50 pedal shaft bent on RHS (probably due to weight of rider's foot on pedal)
• Yamaha CS3 frame with bent top-tube and bent down-tube (probably front-end collision)

SS50 shaft is bent at one end (held next to a straight one)

front lug(s) on RD125 swingarm not straight

CS3 down-tube bent

CS3 top-tube quite badly bent

 

[Morris]

Yes very.

I served my time at Spencer and Sons (long gone now) and my brother followed 5 years later. He changed profession and had A and B woodworking for years.

 

[Seadog]

So. So I gathered together all the bent stuff I've had for years and started putting penny-sized hot-spots on them with the torch. I went down from the #10 nozzle to the #5 and it still seemed like plenty heat.

After several goes on several bits I can say I saw no straightening so tried cooling things more rapidly with cold water and still nothing.

I will keep trying till my gases run out

fwiw the items are:

• Yamaha RD125 swing-arm with bent front lugs (due to someone trying to push Metalastik bushes from it on a press)
• Yamaha CS3 centre-stand bent and creased (possibly due to someone sitting on the bike on its stand)
• Honda SS50 pedal shaft bent on RHS (probably due to weight of rider's foot on pedal)
• Yamaha CS3 frame with bent top-tube and bent down-tube (probably front-end collision)

SS50 shaft is bent at one end (held next to a straight one)

front lug(s) on RD125 swingarm not straight

CS3 down-tube bent

CS3 top-tube quite badly bent

I'd be inclined to start with something "easy", such as a piece of bent rod.

 

[Morrisman]

So. So I gathered together all the bent stuff I've had for years and started putting penny-sized hot-spots on them with the torch. I went down from the #10 nozzle to the #5 and it still seemed like plenty heat.

After several goes on several bits I can say I saw no straightening so tried cooling things more rapidly with cold water and still nothing.

I will keep trying till my gases run out

fwiw the items are:

• Yamaha RD125 swing-arm with bent front lugs (due to someone trying to push Metalastik bushes from it on a press)
• Yamaha CS3 centre-stand bent and creased (possibly due to someone sitting on the bike on its stand)
• Honda SS50 pedal shaft bent on RHS (probably due to weight of rider's foot on pedal)
• Yamaha CS3 frame with bent top-tube and bent down-tube (probably front-end collision)

SS50 shaft is bent at one end (held next to a straight one)

front lug(s) on RD125 swingarm not straight

CS3 down-tube bent

CS3 top-tube quite badly bent

The theory is that when you heat the metal it expands and compresses the colder metal around it a bit, then when it cools off and the bit you heated returns to its normal size it pulls the surrounding area in a bit, because it’s now smaller, where you compressed it.

There has to be some resistance around where you are heating to cause the metal to be crushed. You can’t shrink a length of round bar, for example, by heating all around it in one place then letting it cool. It goes back to the same length.

 

[Brad93]

So. So I gathered together all the bent stuff I've had for years and started putting penny-sized hot-spots on them with the torch. I went down from the #10 nozzle to the #5 and it still seemed like plenty heat.

After several goes on several bits I can say I saw no straightening so tried cooling things more rapidly with cold water and still nothing.

I will keep trying till my gases run out

fwiw the items are:

• Yamaha RD125 swing-arm with bent front lugs (due to someone trying to push Metalastik bushes from it on a press)
• Yamaha CS3 centre-stand bent and creased (possibly due to someone sitting on the bike on its stand)
• Honda SS50 pedal shaft bent on RHS (probably due to weight of rider's foot on pedal)
• Yamaha CS3 frame with bent top-tube and bent down-tube (probably front-end collision)

SS50 shaft is bent at one end (held next to a straight one)

front lug(s) on RD125 swingarm not straight

CS3 down-tube bent

CS3 top-tube quite badly bent

you've not understood the process. Watch the videos again

 

[arther dailey]

He does have rather a strange persona

I think most super brains have , look at patrick moore ,genius but the same /similar .

 

[foy9999]

The theory is that when you heat the metal it expands and compresses the colder metal around it a bit, then when it cools off and the bit you heated returns to its normal size it pulls the surrounding area in a bit, because it’s now smaller, where you compressed it.

There has to be some resistance around where you are heating to cause the metal to be crushed. You can’t shrink a length of round bar, for example, by heating all around it in one place then letting it cool. It goes back to the same length.

Yes. I only heated the parts on the outside of the bend. I understand that heating it all round is pointless as you want one side to contract/shrink

 

[Misterg]

I only heated the parts on the outside of the bend. I understand that heating it all round is pointless as you want one side to contract/shrink

You would also need to hold the bend in place to stop it moving as you heat - in the bridge video, they use jacks to hold the girder in place while they heat. If you don't hold it, it'll get more bent when you heat it, and return to where it was when it cools.

 

[chrismac]

In some of those images I think I can see where you have applied heat, the last one for example, is that the heat mark just below the wood, I take it there will be a down tube just out of the photo, that will need some persuasion to allow the top tube to come up,

The first one the bent shaft will be a good starter I would say, nice and straight (no pun intended) forward to work on.

 

[Beeezer]

I served my time at Spencer and Sons (long gone now) and my brother followed 5 years later. He changed profession and had A and B woodworking for years.
A and B timber….my father was friends with him and used to get timber from him ( can’t remember him,s name) then I carried on getting timber off him… farndon rd.