Mystery solved

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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Mystery solved

Post by gary_f » Sun Aug 31, 2008 5:01 pm

A previous post explained my problem with suddenly degraded performance of my Edwards vacuum pump. I changed the oil several times, it didn't help. I had about resigned myself to tearing it apart. I had soldered a brass flare fitting onto the pump inlet pipe that I used to connect my vacuum gauge. Running the pump one last time, I ran my finger over the solder around the fitting, watching the gauge. With my finger against one side of the solder fillet, I saw the gauge take a quick drop.

There was a pinhole leak that was almost invisible. Why it ran for a month before opening up is not clear.

Richard's warning about measuring vacuum at the pump head with "near zero length" of pipe was another way of saying treat all joints with suspicion. I was too focused on my oil contamination theory to look at the obvious. The noobie learns another lesson; thanks guys!

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Richard Hull
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Re: Mystery solved

Post by Richard Hull » Tue Sep 02, 2008 3:41 pm

Lovely posting and sage advice. Isolating vacuum problems begins way, way back at the mechanical pump as this is where the bulk of all the vacuum work is done. We live and we learn.

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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