Air Bubbles in oil

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Richard W." <potluckutk-at-comcast-dot-net> 

Hi all,


Transformer oil from a pig.
I've noticed that when filling a chamber with a transformer inside that it 
takes several days of periodically pulling a vacuum before I see no more 
bubbles. Though they become REALLY small I'll pull vacuum until I see none 
at all.

Something else too.
A while back I built a containment system with 1" clear acrylic for a large 
transformer. Anyway, after doing the above all seemed fine except there was 
one air bubble at the top about the size of a dime. (up under the flat 
surface of the top) It's location made it impossible to get at even if the 
thing was turned upside down. (long story) Also the location of the bubble 
was no threat to anything at all anyway so I just ignored it.
A few weeks later while looking for any signs of leaks no matter how small 
(found none at all) I noticed the bubble was gone! What the?
All I can figure is that it dissovled into the oil somehow.
The containment is sealed but with an "expansion chamber" vented to the 
outside to allow expansion and contraction of the oil and still remain 
sealed. There's no way for air to get into the main area. I also use 
emergency pressure "pop-out plugs".

Does this happen? Can "stuck" bubbles eventually dissolve?

I'm asking because I completed another containment system using 1" acrylic 
but this time for a piggy. And again I see a couple bubbles about the size 
of a pea I can't get at.

Rick W.
Salt Lake City