Heat Straightening

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ctwo
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Location: Silly Cone Valley

Heat Straightening

Post by ctwo » Tue Nov 29, 2016 2:35 pm

More than a year ago Mr. Fenner mentioned heat straightening (shafts) techniques that he had learned from old time professionals. He said some day he may share the knowledge with the community, or perhaps a select few apprentices. I think he gave a demo at the last "summer bash" gathering. I think he also demonstrated the procedure in his recent video, but did not explain much. Seems rather simple.

center of shaft, find high spot, heat small area with torch, then rapidly cool with wet air.
split the remaining half, find the high spot and repeat.

Does anyone have further to add?
Standards are so important that everyone must have their own...
To measure is to know - Lord Kelvin
Disclaimer: I'm just a guy with a few machines...

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warmstrong1955
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Re: Heat Straightening

Post by warmstrong1955 » Tue Nov 29, 2016 8:14 pm

That pretty much covers it.
Venturi gun, or even a water hose, or a bucket of water will do it too.
What takes the time to learn, is how much heat, and how large an area, to move what you need to move. A few thou can be touchy.
It is an art!
We had some guys in our driveline department, that could, more times than not, get it with one hit. And fast. Comes from doing it so often.
Changes a lot with length, diameter or thickness, wall thickness etc. Those guys were fun to watch.

It also works on plate too. I've heat straightened many a bucket and boom after welding repairs, so the bores in the two plates were aligned again, and you could slide in a pin.
Also have done it with brand new buckets & boom, when things weren't equalized before they were bored.

Bill
Today's solutions are tomorrow's problems.

RickBarb
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Re: Heat Straightening

Post by RickBarb » Wed Nov 30, 2016 11:06 am

Would this work for straightening a rifle barrel!

Rick

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warmstrong1955
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Re: Heat Straightening

Post by warmstrong1955 » Wed Nov 30, 2016 11:13 am

RickBarb wrote:Would this work for straightening a rifle barrel!

Rick
Yes, but I would wonder what the heat & rapid cooling would do to the metallurgy of the barrel.
I think I would consult a good gunsmith or two, before I tackled that one.

Bill
Today's solutions are tomorrow's problems.

earlgo
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Re: Heat Straightening

Post by earlgo » Wed Nov 30, 2016 11:41 am

RickBarb wrote:Would this work for straightening a rifle barrel!
Rick
There are barrel straightening vises for this. Heat straightening was never mentioned at the Colorado School of Trades when I was there. I couldn't find a picture of the one in the shop, but they are available.

--earlgo
Before you do anything, you must do something else first. - Washington's principle.

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SteveM
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Re: Heat Straightening

Post by SteveM » Wed Nov 30, 2016 4:49 pm

Keith Fenner's latest videos (4 parter on replacing a broken prop shaft) includes some heat straigtening.

Steve

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Nelson
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Re: Heat Straightening

Post by Nelson » Fri Dec 02, 2016 8:52 am

Excellent videos on the subject- watched them myself. Apparently, the heat "relaxes" the metal back into its original position. Fascinating.
Nels
Founder, Hobby-Machinist.com
SB 10L Lathe in pieces, Burke #4, Van Norman #12

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