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Tubing annealing - general
While not required for most bending and forming situations, should you need all or part of a tube to be in the "dead soft" condition, the following procedures will achieve this.
Laboratory grade annealing:
For "proper" annealing, the manufacturer recommends using a reduction oven with preferably, a nitrogen atmosphere to prevent oxidation, and "cooking" the tubing at 2100-2300 degrees F for 3 hours. Then allowed to naturally cool (heat off, still in oven) to room temperature. This will maintain material surface brightness and alloy composition.
The hobby method:
A detailed discussion with the manufacturer or our intended uses in the hobby marketplace yielded a much more down-to-earth process.
In a well ventilated area, using your favorite butane torch, heat the tube (or portion you want annealed) to a bright "cherry" red and allow to cool to room temperature. Carefully (remember, it's soft now) drag the tube through fine steel wool to return the surface to a bright condition. Wipe the tube clean with a tissue and alcohol. Voila... annealing is finished!
Remember, this tubing is in it's softest condition now and can easily be damaged. If you need to re-temper the tube, you can try a reheat and water quench, but hardness is tough to control so results may vary. Again, trial and error here.
Annealing tubing end(s) before flaring):
This annealing procedure is used before flaring tube ends for mounting of lampshades (constructing streetlights and building lights). Details of this process can be found here.
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