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Old 08-02-2022, 02:37 AM
Lowe.Buuck Lowe.Buuck is offline
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Join Date: Jul 2017
Location: Minnesota, USA
Posts: 42

I got interested in this topic a few years back. Not a lot of information online about the specifics.

The "Bible" on the topic is Flame Straightening Technology for Welders by John P. Stewart. 106 pages describing 36 processes with illustrations.

Welding Fabrication & Repair by Frank M. Marlow, P.E. has some information and illustrations on Flame Straightening in Chapter 4, Bending & Straightening.

Fundamentals of Flame Straightening (32 pages) is available as a PDF from Linde and BOC.

Removal of Out-Of-Plane Distortion in Mild Steel Panels Using Flame Heating by Larry Lee Janca at MIT. 164 page PDF.

One important thing to note is it takes a lot of heat. If you plan on using a large OA rosebud make sure you pay attention to the acetylene withdraw rate on your tank. You can only remove 1/7 of the tank volume per hour. If you withdraw more than that you will also remove some of the acetone from the tank.

I have a 150,000 btu OA rosebud. On a 150 cuft tank you can only use it 9 minutes per hour.

You may want to look at rosebud tips designed for oxy-propane. The tanks only contain propane and the only limitation is the rate that liquid propane converts to vapor. You need one 100# tank per 100,000 btu of torch capacity. Small BBQ tanks don't provide enough space for the liquid propane to convert to vapor fast enough to supply large rosebud tips.

You can plumb multiple propane together to supply larger tips.
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