Homebrew PCBs

Stefan
I remember you talking about having an issue with the etchant forming a 
vortex around the bottom of the pipes.
Originally I was thinking you should put a plate on the bottom of the 
pipe that was bigger than the vortex.  Took me a second or two to figure 
out that would just make things worse. 
Than the thought occurred to do the the opposite - constrain the fluid, 
and here are a couple of ways:
Use a plate that does not move, and that keeps the fluid from developing 
a vortex outside of the pipe.
Place crumpled plastic mesh at the base, that would induce a bunch of 
drag and slow any vortex.
Place plastic vanes that are lined up radially from the bearing out. 
If they go higher than the fluid, they would preclude a vortex from 
forming except in the space between them and the spinning tube, which 
can be minimized.
Richard