Compass Liquid
- Thread starter jorgefife
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Jorge
I seem to recall from my Navy days that they are filled with alcohol, but I'm not sure. Hopefully one of the experts will get on here soon with better info.
I seem to recall from my Navy days that they are filled with alcohol, but I'm not sure. Hopefully one of the experts will get on here soon with better info.
Its a low viscosity mineral oil. When I did mine I filled it from the bottom where there is a little plug. Being upside down lets you fill it all the way up and burp the air bubble out.
Some compass liquids are actually under a vacuum in the globe, I have heard. That means a compass repair guy needs to do the work, I assume.
Without knowing which compasses by brand it is tough to say. Some brands used a light weight mineral oil and most others used Odorless Mineral Spirits. You don't want to used the wrong fluid as it can change the design characteristics for damping.
If it's a Ritchie flip it over and remove the plug and re-fill with Ritchie Compass fluid. You may have a bad o-ring on the drain plug or a bad o-ring sealing the globe.
Until 2001, Ritchie compasses were filled with a high quality odorless mineral spirits. Ritchie now uses a fluid called Isopar L® that has similar properties but some added benefits over odorless mineral spirits. These two fluids can be mixed together.
Ritchie began using Isopar L as dampening fluid during 2001. This fluid is a high-purity isoparaffinic solvent very similar to Odorless Mineral spirits.
Ritchie changed to this fluid because it has a higher flash point and conforms to most of the world's shipping regulations. It is important to note that some other manufacturers use Isopar M as their dampening fluid. ISOPAR M should not be used in Ritchie compasses. Hamilton Marine sells Isopar L/ Ritchie Compass Fluid but many places sell odorless mineral spirits.
Ritchie also suggests: "Dampening Fluid - Be sure to subject the fluid to a vacuum equivalent of 28 inches of mercury for a minimum of 15 minutes before sealing it in the compass. This step prevents the formation of a bubble in the fluid due to temperature changes."
An old trick to get around that, which often works very well, is to stick the Isopar L or Odorless Mineral Spirits in the freezer for a while then fill the compass with it.
If it's a Ritchie flip it over and remove the plug and re-fill with Ritchie Compass fluid. You may have a bad o-ring on the drain plug or a bad o-ring sealing the globe.
Until 2001, Ritchie compasses were filled with a high quality odorless mineral spirits. Ritchie now uses a fluid called Isopar L® that has similar properties but some added benefits over odorless mineral spirits. These two fluids can be mixed together.
Ritchie began using Isopar L as dampening fluid during 2001. This fluid is a high-purity isoparaffinic solvent very similar to Odorless Mineral spirits.
Ritchie changed to this fluid because it has a higher flash point and conforms to most of the world's shipping regulations. It is important to note that some other manufacturers use Isopar M as their dampening fluid. ISOPAR M should not be used in Ritchie compasses. Hamilton Marine sells Isopar L/ Ritchie Compass Fluid but many places sell odorless mineral spirits.
Ritchie also suggests: "Dampening Fluid - Be sure to subject the fluid to a vacuum equivalent of 28 inches of mercury for a minimum of 15 minutes before sealing it in the compass. This step prevents the formation of a bubble in the fluid due to temperature changes."
An old trick to get around that, which often works very well, is to stick the Isopar L or Odorless Mineral Spirits in the freezer for a while then fill the compass with it.
Isopar.. Great stuff.. We used to make it here in Baton Rouge back when it was a natural oil based fluid.. now it is mostly synthetic and most is made at the Baytown plant.. sooooo Jorge, there are a bazillion gallons of the stuff just 12 miles north of your location, but ya probably won't be able to buy any in a small enough quantity except at West Marine or Ritchie .. Happy hunting..
Maine Sail pretty well summed it up. If I had a nice Ritchie, I would definitely spring for the Isopar L. But, if you have an old compass you don't mind playing with, I have had good luck with the mineral oil available at your local pharmacy - cheap and readilly available. I have used pharmacy grade mineral oil in the old Aquameter Gemini that came with my Hunter. The tip about chilling the oil sounds neat, as long as it doesn't get too thick to pour!
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