It's alcohol-based.

=============================

Actually not, at least not any more. I once damaged an expensive
sailboat compass by refilling with alcohol, only to watch the entire
interior of the globe turn cloudy. It turns out that the correct
fluid is a very clear, low viscosity petroleum based product which
looks and smells suspiciously like white kerosene or mineral spirits.
Some manufacturers reportedly use a silicone based fluid however which
is incompatible with kerosene or mineral spirits. Best advice it it's
a good compass is to contact the manufacturer and get whatever they
recommend.







Half mineral oil, half kerosene.





Not True.

Direct from the horses mouth. E. S. Ritchie and Sons:

What type of fluid is in my Ritchie Magnetic Compass?

Ritchie uses Odorless Mineral Sprits on all Spherical Dome Compasses. Some old
style Flat Top Compass (no longer manufactured) used an Isopropyl Alcohol and
Water mix. This process was stopped in the 1960’s. If you have a Flat Top
Compass it is recommended that you test the fluid to see if it is Odorless
Mineral Sprits or Isopropyl Alcohol.


Barry

Odorless Mineral Spirits = deodorized kerosene

"F330 GT" wrote in message
...





It's alcohol-based.

=============================

Actually not, at least not any more. I once damaged an expensive
sailboat compass by refilling with alcohol, only to watch the entire
interior of the globe turn cloudy. It turns out that the correct
fluid is a very clear, low viscosity petroleum based product which
looks and smells suspiciously like white kerosene or mineral spirits.
Some manufacturers reportedly use a silicone based fluid however which
is incompatible with kerosene or mineral spirits. Best advice it it's
a good compass is to contact the manufacturer and get whatever they
recommend.







Half mineral oil, half kerosene.





Not True.

Direct from the horses mouth. E. S. Ritchie and Sons:

What type of fluid is in my Ritchie Magnetic Compass?

Ritchie uses Odorless Mineral Sprits on all Spherical Dome Compasses. Some
old
style Flat Top Compass (no longer manufactured) used an Isopropyl Alcohol
and
Water mix. This process was stopped in the 1960's. If you have a Flat Top
Compass it is recommended that you test the fluid to see if it is Odorless
Mineral Sprits or Isopropyl Alcohol.


Barry