Fluid for refilling a compass

Evinrude Boater

Lieutenant Junior Grade
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Jul 6, 2004
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1,144
I've read various discussions on this topic yet there still doesn't seem to be a consensus on the type of fluid to be used to refill a compass. I have an inexpensive Aqua Meter compass that's dry and there was no oily residue. Could it be some form of alcohol that was used? Why do they recommend a mixture of alcohol and water? Why not straight alcohol?
 

Ned L

Commander
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Sep 17, 2008
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2,268
Re: Fluid for refilling a compass

I am aware of only 'compass oil' (mineral oil) or alchohol being used in compasses. I have never heard of any problem using straight alcohol (other than it is more difficult to obtain). I've always just used rubbing alcohol (drug store kind (70-90%). - Hint- Put both the compass & the alcohol in the refridgerator (or freezer) overnight before filling & the bubble will stay away longer (as long as there is no leak).
 

daymienrules

Cadet
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Jun 9, 2009
Messages
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Re: Fluid for refilling a compass

I had to refill an autometer procomp liquid filled gauge a few years ago. Took a whole lot of research, but it ended up being a $3 bottle of glycerin from the drugstore. I know it's not the same thing, but maybe it helps.
 

Evinrude Boater

Lieutenant Junior Grade
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Messages
1,144
Re: Fluid for refilling a compass

I have the bottom plug out of it right now. Do I need to fill it before re-installing the plug or is there a different procedure?
 

Ned L

Commander
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Sep 17, 2008
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2,268
Re: Fluid for refilling a compass

The plug is where you fill it through (can be a bit tedious filling it through that small hole). when full, roll it around a bit to make sure there is no trapped air under any parts.
 

DavidInWilmNC

Seaman
Joined
Jul 20, 2009
Messages
50
Re: Fluid for refilling a compass

I used a large syringe and filled my compass with a 50/50 mixture of antifreeze and water. It's got a slightly funky green color, but it's fading as it's exposed to the sunlight. I figured the mixture won't freeze and won't get nasty like plain water will. It's been a couple of months, but so far, it's fine. I really didn't see that I had much to lose; either fix it (rig it, actually) or buy a new one.
 

witenite0560

Petty Officer 1st Class
Joined
Sep 6, 2008
Messages
216
Re: Fluid for refilling a compass

Well, there's a good reason that, at least in aviation circles, they're called a "Whiskey compass". It should be denatured alcohol. Which, over time and exposure, turns dark and resembles whiskey.
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Fluid for refilling a compass

It depends on who made the compass and what the damping factor is.

The Ritchie compasses I have used used odorless mineral spirits.
 

Evinrude Boater

Lieutenant Junior Grade
Joined
Jul 6, 2004
Messages
1,144
Re: Fluid for refilling a compass

It depends on who made the compass and what the damping factor is.

It's a Aqua Meter and likley "el cheapo". I could buy a replacement for $20 but I like to learn as I discover how things are made and save a few bucks in the process.
 
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