NavList:

Thanks, Dave. This was pretty much my question. How much does the fluid change the ability of the bubble to move around when you tilt it slightly? One would assume that a bubble less inclined to move when tilted slightly would make for a less accurate reading. In my case, I am hopeful that the sealing material can withstand alcohol. I used blue silicon gasket sealant for the removed (lower) window, leaving the upper, curved, window intact.