Compass Failure

[Ben Divin Some]

What causes a compass to go bad?. I have seen two now where the flat bottom warps, moving the balance pin.
First one was my wife's and after many years it looked like maybe a gradual warping of plastic under stress. Now I'm not so sure. Mine looked the same way, but only a little over a year old. Did take it on a few plane trips btw.

Been diving a lot of years. Thought short of backing over one with a car, they were pretty indestructible.
Asked another friend, and he had two die, he thinks from being in a plane. Said he had oil leakage.

Mine were warped bottom, but no leakage. Seems like if it was heat, they would have bulged out uniformly.
Same on the plane. I did try an experiment and put mine in a pan on the stove (this could be dangerous btw) to see if I could flatten out the bottom. Not much luck, but I was amazed at how hot it had to get before I could get the bottom to deform. Any ideas on what causes such a simple device to fail?

 

[michael-fisch]

If you can see an airbubble in your compass - it is defective.
Bubble means the case is cracked and no longer watertight.

You are going to have to replace it, either with a new analog compass the will also eventually break, or, a digital compass built in as part of an expensive dive computer.

Michael

 

[JackOfDiamonds]

Probably the material lost its strength over the years (being hammered by salt water & UV lights) and eventually became weaker and bent under heat / pressure .

I've seen people puzzled about their compass going mad while having a magnetic octo clip swinging right next to it.

If it has served you for so long i think its safe to say you got your money's worth , buy a new one.

 

[Ben Divin Some]

If you can see an airbubble in your compass - it is defective.
Bubble means the case is cracked and no longer watertight.

You are going to have to replace it, either with a new analog compass the will also eventually break, or, a digital compass built in as part of an expensive dive computer.

Michael

Appreciate the note, but I am hopping for a manufacturer to explain why these go bad?

Actually you bring up a good point about the bubble. Why do they no put a bubble in the compass? as it must be level to work, and level is a bit "subjective" underwater, a small bubble would be ideal to help insure the proper aspect. This is the same issue for digital compass, but they can adapt a bit easier for some amount of angle.

 

[Ben Divin Some]

Probably the material lost its strength over the years (being hammered by salt water & UV lights) and eventually became weaker and bent under heat / pressure .

I've seen people puzzled about their compass going mad while having a magnetic octo clip swinging right next to it.

If it has served you for so long i think its safe to say you got your money's worth , buy a new one.

Thanks, that does apply to my Wife's compass, but mine died after barely a year. As an extremely simple device I believe it should last longer. But I was hoping posting here would get a manufacturer to replay as to the construction and what they have found causes them to go bad. What I found the strangest is the way the back of the compass warps. It's like there is a bad reaction between the oil (anyone know what kind, I am guessing silicone), and the plastic.

Heat could cause it, but I would expect it more uniform. Also, I am referring to the back of the hermetically sealed bubble, not the plastic enclosure used to mount it an that has the numbers. That is, I believe, ABS plastic, and show no damage even though ABS is not tough. I am really hoping for some expert knowledge here to run this to ground. I don't mind replacing a compass, what I don't like is not knowing the real cause for failure of an important piece, if humble, dive gear.

Anyone know who actually makes the internal compass part? This looks like something the dive MFG's are just packaging not making.

 

[michael-fisch]

Putting a planned Bubble in a working compass woud require the compass to become a pressure tight vessel > much higher cost. As it is, it's filled with mineral oil and as long as the pressure outside is even the compass isn't affected by depth. An air bubble would end up causing the casing to crack.

Michael

 

[Couv]

Thermal expansion and contraction is the bane of liquid filled compasses. Sometimes they are designed and built well enough to survive-other times not.

Tiny Bubbles? | Dive Gear Express®

See what @captain has to say here and heed his advice:
Love:Hate relationship with Compass