atomicfire
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Heating Mantle Problem
Hey All,
I have a mantle from glas-col that the fiber lining in the rounded section became brittle and broke after just one use. The problem area is about a
3" round section in the very center of the mantle. The rest of the 'fiber stuff' as best I can describe it is still plyable, but this area is 'glass'
like.
Can anyone tell me why this might occur? It was ran at fairly high temperature(~300C) for a few hours, but I would think these kinds of things would
be rated for such duty.
Thanks
AtomicFire
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Arthur Dent
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Was some liquid accidentally spilled on the mantle before putting it in operation?
Mantles are supposed to be operated with some sort of voltage control to avoid overheating it, and should never be operated at their maximum rating
for very long periods of time. Could it be that an ultra hot spot was formed and it degraded the mantle? Is your vessel intact or did this high heat
created a burn mark on the glass?
Robert
--- Art is making something out of nothing and selling it. - Frank Zappa ---
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atomicfire
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A porcelain crucible was used as the vessel and it was in contact with the mantle, although the crucible does have a slight bump in it where I thought
it might have been possible that it 'superheated' an area causing this failure.
The crucible shows no signs of burning or any marks whatsoever.
Not that this is relevant but I have used these mantles in the past with great frequency and have had no problems like this.
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atomicfire
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Update:
After a little investigation, the resistance of the bottom circuit of this mantle (it has 2, top and bottom) is lower then that of the top. The
bottom portion must have reached a higher temperature given they have the same input.
It also seems that only the fiber 'covering' was damaged. The fiberglass packing underneath that the wire is sewn to is undamaged. I think I can get
some other fiber covering and repace that and this will work fine for the future.
I don't know why this fiber covering can't take the high temperature but the main packing and wiring can.
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watson.fawkes
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I
have to second the suggestion that something must have spilled on it. Note: That something might have spilled on it before you got it, at the factory
or even at the glass cloth manufacturer.
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uggbootsadj
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How peaceful and beautiful the country is!
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