Compass Fluid ?

[AndrewB]

I refilled my Plastimo compasses with Johnsons Baby Oil, and wrote up how to do it in PBO Number 569 January 2014. Baby oil is a mixture of liquid paraffin and isopropyl palmitate, the latter made from isopropyl alcohol and palm oil. After four years the choice of Johnsons Baby oil (the unscented type) has proved to be a good one as the compasses have not suffered any damage and the oil seems to be the right consistency. One did leak a little, but that was due to the fact that the O ring under the filler screw was damaged, and a new O ring has solved the problem.

Thanks, Norman_E, for a good tip.

At the start of this season I found my steering compass half empty owing to a cock-up when working on the binnacle a year ago. I remembered this thread when I spotted the local supermarket had an offer on Baby Oil. Dumped the remaining liquid, and the refill with baby oil cost €3. The compass has worked perfectly all season, damped correctly and no discolouring.

As the refilling hole is tiny, I used one of those fine straws that is provided with "3-in-1" oil, taking care not to overfill so the expansion diaphragm could work.

 

[jwilson]

I once ages ago refilled a quality Danforth compass with alcohol: whilst the card still reliably pointed to magnetic north, all the letters on the card were soon floating around inside the glass like a very expensive snow globe. The Danforth agent in Southampton put a new card in for me and refilled with the right stuff. Cheaper than a new compass though.

Be careful: "compass fluid" is not one standard product.

 

[Norman_E]

Thanks, Norman_E, for a good tip.

At the start of this season I found my steering compass half empty owing to a cock-up when working on the binnacle a year ago. I remembered this thread when I spotted the local supermarket had an offer on Baby Oil. Dumped the remaining liquid, and the refill with baby oil cost €3. The compass has worked perfectly all season, damped correctly and no discolouring.

As the refilling hole is tiny, I used one of those fine straws that is provided with "3-in-1" oil, taking care not to overfill so the expansion diaphragm could work.

My refilling tool is a fairly large syringe that came with a kit for refilling inkjet printer cartridges.

 

[Bilgediver]

There are a couple of different types of liquid used for compass damping. One as you say is alcohol based, others use a very light mineral oil. I had a bubble in the oil filled binnacle compass on our last boat and filled it with Lamp Oil which is paraffin with pretensions, completely satisfactory.

Ditto.