plastimo compass oil

[WX]

I have two Plastimo compasses, both with large air bubbles in them. I believe compasses are now filled with a silicon liquid these days. Where can I get this in Australia?

[WX]

Okay, a bit of googling and apparently you can use lamp oil. otherwise known as kerosene...though no the blue tinted stuff we get here. Baby oil has also been suggested but could be a bit too viscous.
It is also recomended that you fill the compass and then put it in the fridge along with the oil you use...get it cold, take it and top it up. When the compass warms up there will not be any bubbles in it,

[HR]

Some compasses are filled with mineral spirits and some with mineral oil (and maybe some with other fluids). Baby oil is mineral oil, although it often has other additives to make it more appealing (almost always a perfume). The perfume doesn't hurt, but other additives (such as aloe vera) might.

When I had a similar problem last year with my Danforth, I took a small amount of the fluid out of the compass and put it in a clear plastic tube, then added baby oil to the tube, shook it up and waited to see if it settled. Once I was sure that the fluids were compatible (ie they didn't settle out into layers), I did the fridge trick and filled the compass. It worked great.

Howard

[WX]

Glad to hear it, now where did I put that baby oil? :D

[Hwyl]

Glad to hear it, now where did I put that baby oil? :D

I could get Scotted forever if I responded to that

[Wooden Boat Fittings]

.
I'm told (although I haven't tried it) that if you put a few drops of the compass liquid onto a piece of clean paper, either it will evaporate or it will soak in and make the paper go transparent.

If the first occurs the liquid is spirit, if the second it's oil.

So you might want to try a bit of five-star instead of baby oil....

I think Howard has the right idea.

Mike

[Bob Cleek]

Compasses are tricky. You CAN fill them sometimes, but it is very possible that the material you use may not be suitable over the long haul. Sunlight exposure can result in discoloration. Some additives can degrade the card. Others can become great growing mediums for types of algae. Although I am a die hard do it yourselfer, I send my compass out for service to a reputable compass adjusting and repair shop on the rare occasions it has needed it. This is one area I'd urge folks to "hire a licensed contractor." Compasses are sort of like watches. You wouldn't try to service your Rolex yourself, would ya?

[Bob Adams]

Rolex??? What's a Rolex? I have used grain alcohol before, although that was long ago.

[WX]

Well I lifted the compass out of it's housing yesterday and I now know it's not baby oil. I am going to give the lamp oil option a go and rather than just top it up I'll replace all the oil in the compass. It looks like it could do with a recharge anyway, there's a bit of sediment of some sort in it.

[kc8pql]

I bet it's mineral spirits. That's what Richie uses.

[WX]

It's interesting that the compass I topped up with baby oil has settled down and works very well, though the bubble is back as big as before. I think it may be leaking via the refill plug as I didn't seal it afterwards.
I'll fiddle some more.

[werner]

google for Rhodorsil , (Rhodia)light silicon oil used in medical appl.
Ondina by Shell is a clear mineral oil .
think the silicon oil would be the safest but the most expensive but I wouldn't mix it with mineral oils

[WX]

Thanks Werner, I'll have a look at it. The baby oil is working out fine though and i got rid of the bubbles using the fridge trick. I've gone ahead and refilled the other Plastimo compass I have and it's fine as well. One's an Offshore 85LV and the other is an Offshore 85LH. Both date from the early 80's.
I'm now in the process of re-calibrating them against a hand bearing compass I know is accurate.

[sdowney717]

mineral spirits because oil when the compass is cold gets too thick and the card wont easily move.
I used a 50 50 mixture once with mineral oil and mineral spirits.
I think I did this to cut down on the vapor pressure of the mixture. What happens when the sun is heating up your compass and the internal pressure rises? Perhaps this is why compass creates a bubble, a little leaks out when the pressure gets too great.
Now should that be low odor mineral spirits?
Or can it be cheap paint thinner.

[Tylerdurden]

I just wonder what we will do when the poles flip. There has been some severe changes in the past twenty or so years.
I don't think I have read or heard that discussion and I am sure there are some pretty good ideas out here.

[sdowney717]

magnetic pole reversals means the earths magnetic field dissappears for a while and lots of dangerous radiation comes down to earth.
How long while earth is without protection?

Also magnetic field of earth has been declining in strength for some time now.

[Tylerdurden]

magnetic pole reversals means the earths magnetic field dissappears for a while and lots of dangerous radiation comes down to earth.
How long while earth is without protection?

Also magnetic field of earth has been declining in strength for some time now.

Agreed, but how are we all with the sextant?
There is a book that just came out , "The Barefoot Navigator" by Jack Lagan which deals with the ancients skills of navigating.
I was planning on getting a copy and maybe it may be handy considering the coming shift. That and plenty of sunscreen.