Compass Air Bubble

[ozzyb]

We have an air bubble in our contest 101. Either I heard or read somwhere that it can be fixed by injecting Baby oil into the space via the access screw. Is this correct or is there some other method of eliminating the air bubble.

 

[seaesta]

I did this a couple of years ago. I was given sound advice on this forum that the best liquid is White Spirit. I used this and it has worked very well since then.

Martin of Seaesta of Whitby

 

[pvb]

Best to fix the leak first...

If there's an air bubble, it usually means that the fluid is leaking out somehow. If you just top it up without fixing the leak, you're likely to get another bubble before too long. Check the expansion bellows first, as it's a favourite spot for leaks.

 

[ozzyb]

Thanks, I think the leak may have been from the filling screw area as there was no other sign of a weep. I'll give the white spirit a try as it sounds the simplest. Did you find it compatable with the existing spirit solution.

 

[yoda]

Don't use neat alcohol - causes implosion of dome after a time - I should know. Have used gin with no after effect but seems a bit of a waste! White spirit sounds like a good alternative.

Yoda

 

[Guest]

I had the same problem last year...for small amounts, white spirit seems the way to go. I ended up draining the whole lot and starting over new because I overtightened the screw, and had to replace the bellows.
Easiest way to fill the compass completely is to put compass and white spirit in the fridge overnight, then get it as full as possible. Once the liquid has warmed up (and expanded) the bubble vanishes.

Good luck!

Martijn

 

[AndrewB]

Be careful with White Spirit.

This isn't a conventional fluid, and may not mix well with what you have. I suggest you first draw off a little more fluid from your compass and test whether it mixes properly with white spirit, and without clouding.

Another home remedy that is sometimes recommended here is Baby Oil. A better option would be to call the compass manufacturers, though it seems from previous reports that most are loathe to sell small top-up quantities of fluid.

Incidentally, leaks from the filling point are unusual, unless you accidentally loosened it sometime. The more usual reason is a failed expansion bellows internally - in which case there will be no sign of external leakage. You risk damaging the compass if you refill it completely in this case. Possibly that's what happened to Yoda's compass (below).

 

[ozzyb]

Re: Be careful with White Spirit.

When I originally posted this I said Contest 101 (was thinking of buying new) sorry its a std. Contest which doesn't have visible external expansion bellows. Are you saying that there are internal bellows which may have taken up some of the fluid. There is no other sign of a leak although the bubble spreads about 10mm down from top.

 

[paulonvt]

I had same problem with a sestral compass, and inded did use baby oil, though I did change the oil completely

 

[pugwash]

Sestrel advised me last month to extract a little fluid and test whether it's oil-based or spirit. Just feel it in your fingers or drop it on some paper. Mine turned out to be special compass oill and I ordered a litre which cost something like 22 quid including postage. Last week I followed advice and put both the compass and the oil in the freezer. WHen they were well chilled I topped up the oil with a dropper and tightened down the screw. As everything warmed up again the very tiny remaining bubble disappeared. I also found that the same oil can be obtained from West marine in the US for $7 a pint. If it's not oil but spirit, you have an excellent reason for putting a bottle of gin on board ("Got to keep the compass topped up, darling!")