Originally Posted by celenoglu
Immerse the whole compass in the fluid you are using to fill it. Keep the filling point at the highest position. Screw the tap in the fluid.
That is a lot of fluid. Maybe that is how Ritchie does it. I was
thinking, maybe a flexible tube screwed into the filling hole, add
fluid to the tube, then rotate/rock the compass while holding
the tube upright until the bubble is gone.