View Full Version : Air in the Compass, what liquid is insite?

06-15-2006, 03:57 AM
Moin moin Woodenboat Forum,

i have some air in my compass and want to fill it up.


But what liquid is insite, and can i do it by myself or better not?

Thanks for answers!
Tschüss Heiko

06-15-2006, 04:36 AM
Aircraft compass' are filled with kerosene- same for nautical one's??

06-15-2006, 08:56 AM
I once repaired a compass with baby oil. It was just the right viscosity, clear, didn't freeze and cheap. Ten years later the compass is still working great.

Dan McCosh
06-15-2006, 08:59 AM
It's difficult to tell. The photo looks like it's old enough for alcohol to have been the fluid. Compass oil is basically mineral oil--far more common. A drop shouldn't be hard to tell the difference. I bought a bottle 30 years ago, and it's still pretty full.

06-15-2006, 11:27 AM
Yep, its either 'compass oil' (mineral oil) or alcohol. When filling it, a trick to help keep the bubble from coming back so quickly is to put the compass and the fluid you will be adding to it in the refridgerator the day before. That helps to drive some of the disolved air out, and it also makes the fluid contract a bit so it will actually be under a bit of pressure at room temperature (which helps to keep the bubble away).

06-15-2006, 12:36 PM
I've heard that it is sometimes kerosine.

06-15-2006, 06:15 PM
Ritchie uses mineral spirits, which is basicly more highly refined kerosene.

Lazy Jack
06-16-2006, 05:10 AM
Mineral oil? Kerosine? Alcohol? Waddayguys talkin' about! You use Whiskey! That thars a whiskey compass!
Or rum...arrrrrr!

Wooden Boat Fittings
06-16-2006, 08:15 AM
Depending on the compass, the liquid could be mineral oil or spirit. I'm told (I haven't tried it) that the easiest way to tell which one your compass is filled with is to tip a little of the liquid on to a piece of paper. If it's oil it makes the paper transparent, whereas if it's spirit it simply evaporates.

Then you refill accordingly (using the refrigerator trick Ned mentions.)

One day I might even try it myself....


06-16-2006, 02:58 PM
Mineral oil? Kerosine? Alcohol?
Moin moin,
Thank you for the many answers!
The problem is the compass disk and the paint numbers on it, i think, not the dearth( <-? german = mangel) of Whiskey.;)
My apprehension is that the paint on disk will loosen.
Tschüss Heiko