With a simple but tedious method.... just carefully pour the
glycerine down the sides of the tank.
Then I leave it to stand for about 30 minutes or so... most of the
remaining bubbles that do get formed will slowly but eventually
rise to the surface. I can't get rid of all the bubbles, but I can
minimise them this way.
It would be far better to be able to have a vacuum pump that can
suck out all the bubbles.... but the device is in another building,
and it's simply too cumbersome to lug a 16-liter tank full of
glycerine from one building to another just to suck out some
bubbles.
