Bakeout - Fail

Every fusor and fusion system seems to need a vacuum. This area is for detailed discussion of vacuum systems, materials, gauging, etc. related to fusor or fusion research.
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Liam David
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Bakeout - Fail

Post by Liam David »

Following a bakeout the other day, I found this worrisome sight:

PXL_20220728_231145364.jpg

Under the high temperatures (130C) the Viton expanded and extruded itself through the narrow gap between the flanges. The four affected seals still held vacuum. However, this was not an unforeseeable problem. The 2.75" conflat Viton gaskets carried by LDS Vacuum changed sometime in the last few years, increasing in thickness and OD, but decreasing in ID (and quality). The change in volume is ~40%. The grooves in my chamber were designed for the old size, but I foolishly decided to proceed anyway... Lesson learned.

PXL_20220730_002133131.jpg
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Richard Hull
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Re: Bakeout - Fail

Post by Richard Hull »

Good to know, Thanks! I only use Cu gaskets. Expensive and sometimes cantankerous to install at odd angles or in tight spots, but solid.

Richard Hull
Progress may have been a good thing once, but it just went on too long. - Yogi Berra
Fusion is the energy of the future....and it always will be
Retired now...Doing only what I want and not what I should...every day is a saturday.
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