Compass - low on fluid

[bob_deb]

Hi Everyone,

I have another fix-it question, My compass, mounted at the helm, is low on the fluid inside. This makes it difficult to read. Is it possible to repair it or refill it with what ever kind of fluid it is or should I replace it ??

Thanks - Bob

[rebel heart]

Compass fluid! Seriously.. that's the name. You can pick it up at any chandlery. Or, mineral oil.

[S/V Illusion]

As you might expect, simply replacing the fluid, which is possible on most compasses, won't cure the leak. The most common source of a leak is the diaphram which can be replaced if you are familiar with or take the time to learn to do it correctly. Many mfgs have a pretty good description and parts breakout diagrams on their web sites you could check out to get a feel of the complexity. In most cases, the manufacturers' repair facility cost will usually equate to the cost of replacing it, particularly if it is a good quality large compass and even if a bit cheaper to have it repaired and re-calibrated, you still end up with an old compass.

[Ex-Calif]

It is useful and important to find out what is in the compass already. It could be mineral oil, it could be kerosene, it could be mineral spirits and it could be a blend.

You can replace whatever is in the compass but you should know what the materials of the compass are made from so that you have no risk of damaging any internal components, compass card, etc. Some fluids can also be mixed but yuo gotta know what you are doing.

You can flush the compass with isopropyl alcohol or the new replacement fluid.

Here is an MSDS on the Airpath compass fluid.

COMPASS FLUID

I hit the West Marine catalog for compass fluid and the Ritchie stuff (Isopar L) came up for $12.99 a pint. The aircraft version is $1.65 a pint.

I doubt that the Isopar stuff is worth $11 more per pint...

AIRPATH COMPASS REPAIR KITS - COMPASS FLUID: 1/2 PINT & QUART from Aircraft Spruce

In regards to the "leak" - If it is an external leak you'll want to get it fixed. If it's just the o-ring on the filler or something you could be ok just filling it. Unless I was getting visible wetness and the compass was OK otherwise, I'd just fill it and move on.

[Pelagic]

You need to be more specific on what Manufacturer and type of mag compass it is? How old? Vissible wetness? before we can be specific.

Dan gives a good summary and advice, except the alcohol cleanse could be destructive on some cheaper models.

[David M]

Just call the manufacturer and see what they recommend.

[Pblais]

Most compasses can be serviced and repaired. Just adding fluid isn't what you need. For far less than half price a total overhaul can be had. There was a compass shop in Annapolis, MD that provides the service.