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Re: Ovens.
>>>I have not bombarded with an oven in my shop, because I have found that
direct heating with a hydrogen bushy annealing torch, painting the tubes, is
much faster and more flexible for a small custom neon shop. I, too, do not use
electrical bombarding, mainly because it is inefficient and unsafe. This method
has never been described in SOT, but it really avoids all the complexities that
Wayne Strattman identified in his article there talking about it. All you do is
heat the glass just up to the point where the orange sodium flame just starts to
come up, and go over it until the vacuum drops again, while induction heating
the electrodes. You continuously pump on the tube, so you get out more of the
impurities, and you can monitor the progress of the bombarding process by
watching your vacuum gauge go up initially, then down to base pressure again as
the outgass products get depleted. Jeff<<<
Jeff - any particular reason you use a 'hydrogen' torch, as opposed to natural
gas? Also, how do you support the tubing above the bench (I assume) for the
heating process? Do you try to keep the whole piece hot at once, or do you work
from the far end back towards the tubulation? Your process sounds interesting
enough to try, especially for single-ended pieces and small dia. tubing.
Thanks.
Telford Dorr