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What is the fluid in our compasses?


Ramness

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What is the fluid in our compasses?

 

Started to notice air bubbles forming inside my compass several weeks ago. Then just recently I had an odor coming out of the center console in my truck. Finally figured out the smell was the fluid leaking out of my compass, sort of has a orangey smell. Just wondering what the fluid is and if I need to wash every thing off that is in there with it.

 

Compass is a “Map Compass” made by Coleman, found this picture of it on their site

814-630T_x150.jpg

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I can't say exactly what type of fluid Coleman uses in their compasses (or whoever makes their compasses), but in professional equipment (like aircraft and ships) it is petroleum based and can be hazardous. I doubt if consumer compasses use the same fluid, could be silicone based...I would consider cleaning the stuff it came in contact with just in case.

 

Bubbles seem to be normal in general purpose compasses, like most of us use, it usually happens when you go up in elevation then back down to sea level, or close to it, they usually aren't a problem.

 

Leaking is NOT normal! I would try and get your money back if it's not to late...consider getting a Silva...

 

____________________________________________________________

It's not about the mistakes we make, it's about what we learn from them....

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Never really thought about it before.

 

I know from working in the oil patch that all of our local indicators (pressure, temperature gages, etc.) are filled with glycerin. Pretty harmless stuff.

 

I would agree with mtnsteve that leaking is not normal. You might consider returning it or buying a different (better?) compass.

 

R icon_smile.gif

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Never really thought about it before.

 

I know from working in the oil patch that all of our local indicators (pressure, temperature gages, etc.) are filled with glycerin. Pretty harmless stuff.

 

I would agree with mtnsteve that leaking is not normal. You might consider returning it or buying a different (better?) compass.

 

R icon_smile.gif

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I am assuming the fluid varies with manufacturer and price. I notice some are listed as freeze-free and some are not.

I looked quick on the net and a childs compass was recalled because it leaked it's fliud which contained kerosene.

I had a cheapie pin-on globe type freeze and break overnight. It was only about 25º out, so I am thinking it was filled with Oriental water. Just as well, it only pointed North when it was aided anyway.

 

I'd call or email Coleman, I would think they could answer the question on your compass.

 

Never date a girl whose father calls her princess - chances are she beleives it.

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Its too late to return it, Bought last august I believe. When I found this one was leaking I had already purchased another one, as I thought I had lost it. Found it when I went digging through the console to find where the smell was coming from. I’ll send a Email to Coleman and see what they say, maybe they will send me a new one that I can pass on to my cache hunting buddy that currently doesn’t have one.

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Some compasses come with air bubbles. I have a compass on a survival whistle/waterproof match holder. Each and every one in the store had air bubbles. Since you hold this compass as you would hold a wand, the bubbles come in handy to let you know you are holding the compass exactly vertical to the ground. Kind of like the bubble in a carpenter's level.

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This what Silva had to say on their web site.

 

Bubbles

At altitude (above 500 to 1000 meters) bubbles may form in the fluid. The cause is a drop in atmospheric pressure and/or low temperature. This can occur in any compass. The bubble will disappear, when normal conditions return.

Obviously, air can get into the fluid through crack damage in the capsule. A hairline crack damage in the surface of the capsule may not cause a leak to occur for weeks or even months. Such damage is not covered by warranty.

It is not economically viable, to repair a cracked capsule, but it can be replaced by your SILVA dealer at much less then the the cost of a new compass.

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In aviation compasses, it's some sort of flammable fluid. If you can't use the compass to get out, and you need to survive 'til help arrives, you can light the fluid to start a fire.

 

Just don't start a fire under a tree full of snow...

 

---------------

wavey.gif Go! And don't be afraid to get a little wet!

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Date: Fri Jun 5 11:21:23 1998

Posted By: Lillian Mundt, Faculty, Clinical Laboratory Sciences, Finch University of Health Sciences/The Chicago Medical School

Area of science: Other

ID: 895715666.Ot

--------------------------------------------------------------------------------

Message:

 

This question is outside of my area of expertise.

However, there are only several fluids used in compasses, gages, etc.

that I know of. Of more importance is the viscosity of the mixture, usually

mixed with a solvent (water or alcohol)

 

Fluids commonly used are:

Water - probably not in this case, could freeze

Alcohol - possibly

Glycerol - possibly, if thinned out

Ethylene Glycol - green tint, possible if thinned out.

 

4497_300.jpg

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Which other scientists successfully improved the compass?

 

Another problem was solved by a Scottish scientist of the 19th century, Sir William Thomson, who later became Lord Kelvin. He introduced a compass design with the needle system slung on fine silk threads through a very light skeleton card. The card was made of fine rice paper so that there was very little friction on the pivot. Jewels, such as agate and ruby, were used to reduce friction on the pivot itself.

 

It was also realised that compass movement could be dampened by filling the bowl with liquid. Alcohol is ideal for this since it only freezes at a very low temperature. Liquid compasses, because of their greater steadiness, are used in most ships, especially small boats and lifecraft.

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