A philosophical/theoretical question about my compass...

[Noah]

Last week I filled my big old bronze Kelvin & White Compass, but I couldn't quite get all the air out. I was deeply disappointed that there was still one small bubble, but I put it back into the boat anyway.

Two days later there is no bubble...Where did it go? The compass isn't mounted on it's side, and I haven't done any sailing so the boat hasn't heeled over...

For the life of me I can’t figure out where the bubble went. The glass on the top of the compass isn’t cracked so it didn’t leak up…not that it would anyway.

[J. Dillon]

It may be lurking under the card. :( Also the compass warmed up compressing the bubble. ;) That's what happened to some of mine. ;)

JD

[Meerkat]

What are you using as a damping fluid?

Whatever it is, next time get it as cold as possible (short of freezing), fill it as much as possible and then seal it. Small bubbles will disappear until the next time you're sailing through Artic waters ;)

There is one risk with this method: the fluid will end up upder some pressure. T'would be best to make sure your seals are up to it.

[John B]

I think you should be happy it isn't a Sestrel..ummm( thinking of model) Conquest I think its called. If it was you'd just have the fluid all over your cockpit.
Ask me how I know. :eek:

[JimConlin]

The bubbles vary with temperature. A compass that's OK in summer will develop a bubble in the fall.

No worries.

[Mike Field]

.
Hh'mmm... Seems to me we've had this conversation before. It might have been BM, but a search could be worthwhile all the same.
.

[Noah]

In the back of my mind I was thinking temperature, but I couldn't quite figure out how the bubble would go away completely. I wouldn't have thought that you could "carbonate" lamp oil like that...

BTW, I did end up using lamp oil because that's what was in there before. Hopefully this won't harm anything. The dampening is good with lamp oil, and the compass didn't seem to have any problems with it before.

Noah

[paladin]

...and in an emergency you can drill a hole in the plexiglas, add a wick...and have a neat lamp......

[Hwyl]

Should have used gin "hic"