White mold? bacteria? fungus? in compasses

[AKuhlmann]

Hello!

Bangor Student Caving Club are having a problem where the compasses we have in our emergency kit (occasionally helpful when a little lost) keep getting this weird white mold or fungus type thing growing inside the fluid in them. This in turn eventually creates the world's largest compass air bubble and this makes it unusable and the liquid a cloudy white.

Does anyone know what this is and why it's happening? They are mostly stored dry and rarely see the light of day so I am baffled. They also don't have any signs of damage.


Cheers for any help,

Aidan

 

[alanw]

What model of compass? Silva, Suunto or something else?

 

[langcliffe]

I remember that this used to happen to Suuntos.

 

[AKuhlmann]

Silva Field 1-2-3. I believe is the model. Basically small and cheap but it’s odd it’s happened when they’ve not been damaged

 

[andrewmcleod]

While compasses are very useful (if you have a survey to go with them), they don't need to be terribly accurate for underground use. Generally just knowing which way is north, east, south or west is sufficient to assist with using the survey, so buy some cheap tiny ones.

 

[Babyhagrid]

If you know your geology you can work north out from the dip of the limestone, in a pinch.

 

[Badlad]

Could it be a manufacturing issue? Contaminated fluid?

 

[AKuhlmann]

While compasses are very useful (if you have a survey to go with them), they don't need to be terribly accurate for underground use. Generally just knowing which way is north, east, south or west is sufficient to assist with using the survey, so buy some cheap tiny ones.

Yeah we have done, but it's still annoying it's happened

 

[AKuhlmann]

If you know your geology you can work north out from the dip of the limestone, in a pinch.

While that works for experienced cavers, teaching people about the ins and out of the local geology for every trip isn't a very robust solution

 

[AKuhlmann]

Could it be a manufacturing issue? Contaminated fluid?

It could be. The odd part is the white stuff seems to come and go. In one of them it’s completely disappeared but I know in a weeks time it will return again

 

[hannahb]

I'm really curious about this. Have you got a photo? Does the bubble come and go or once it's appeared does it stay?

 

[hannahb]

Wondering if the oil is hygroscopic, and perhaps there is a slow leak, and moist air is being drawn in and then the oil is drying out, perhaps with change of humidity/temp in different locations? I think they are filled with kerosene or mineral oil so I would be surprised if it was bacteria or fungus etc but I could well be wrong

 

[wormster]

Have the compasses been at high altitude?

I had a compass that had been up Kilmanjaro, it went out ok but came back with a bubble, and it was a basic Silva.

 

[Wayland Smith]

It could be. The odd part is the white stuff seems to come and go. In one of them it’s completely disappeared but I know in a weeks time it will return again

That sounds rather like olive oil going cloudy in cold conditions.
Is something in the liquid filling crystalizing out at lower temperatures and going away when warm?

 

[paul]

If it's a Silva compass, Silva say "The compass housing is filled with a specially developed anti-static liquid that provides good transparency and fast setting time as well as optimal damping, stability and precision." ( https://silvasweden.com/en/blogs/compass-school/hur-kompasser-fungerar )

 

[Digit]

Simple experiment: Take one home for a few days, keep in a warm dry place such as your living room for 48 hours, then 48 hours in a cooler damper place such as your car boot or garden shed and note any changes.

 

[AKuhlmann]

I'm really curious about this. Have you got a photo? Does the bubble come and go or once it's appeared does it stay?

Two of the compasses side by side. The top one had the white stuff in it until earlier this week and its disappeared again. The bubble size has also grown again with no signs of leakage.

Have the compasses been at high altitude?

I had a compass that had been up Kilmanjaro, it went out ok but came back with a bubble, and it was a basic Silva.

Nope, these compasses have never been higher than 500m. That would have been my first thought having gone through a few compasses myself that way.

Simple experiment: Take one home for a few days, keep in a warm dry place such as your living room for 48 hours, then 48 hours in a cooler damper place such as your car boot or garden shed and note any changes.

I will try this and keep a log! Will update you in 2 days

 

[ChrisB]

I suspect there's been a chemical reaction forming something that crystalises and then redissolves, possibly by giving off a gas?

 

[hannahb]

When the white stuff is there, is the bubble sometimes also present, or does it appear when the white stuff disappears?

 

[pwhole]

Just found this - admittedly it's from 2010:

https://forums.ybw.com/threads/silva-102b-h-compass-replacement-fluid.254566/