NavList:

I have experimented with a number of artificial horizon liquids and find used motor oil works best. Used oil is dark and has excellent leveling and reflective characteristics, usually eliminates the need for the sextant direct view filter and resists most wind ripples if your AH does not have a wind screen.

Oil, unlike water, will not fog your AH wind screen glass, another advantage to using it.

Any auto repair or old style gas station will gladly give you a soda bottle full.

To avoid any cleanup mess, first put a piece of Saran Wrap or other brand of thin food wrapping plastic film in your artificial horizon. The plastic film keeps the oil from soiling your AH. Now add the oil in to whatever level you need and take your sights. For cleanup, recycle your oil back to its container, remove and discard the plastic film. That's all. Oil has never come in direct contact with your AH; no mess, no fuss and no loss of oil either.

Ed Popko