bubble in compass dome

[gerlachm]

Don't know if this was treated before in this forum but I have bubble in my 18 year old plastimo horizon 135 compass. Plastimo recommends to buy a new one but as the old one does not seem to be leaking I would consider it a waste to throw away the compass just because of this bubble. Does anybody know how to top up the compass fluid? I managed to find out what kind of liquid it is, seems to be isopar L which is quite common for those applications. If somebody has anyexperiences I would be happy to read them. Even better some pictures! Thx, Martin

[Zanshin]

Usually one could use a syringe with as small a diameter needle as possible through the rubber seal in order to draw out the air bubble, but I'm not sure how access is on the old plastimo compass. have you looked at the seal.

[omoo]

Years ago I read that one way to eliminate the air bubble was to drill a small hole in the plastic sphere, inject enough liquid to displace the bubble and then seal the hole with a clear silicone sealant.

[super g]

Not sure of the make of binnacle compass I had but it was on a Jeanneau Sunshine so possibly Plastimo. I got rid of the bubble in the following way.

Step 1: Put in fridge for a while to maximise bubble.
Step 2: Invert and tilt so bubble will aspirate when plug is removed
Step 3: Very tricky without a syringe, top back up with a little fluid.
Step 4: put the bung back in

I seem to recall having to maintain tension (pull) on the rubber diaphragm to maximise the volume of liquid inside.

I actually used a bit of white spirit and two years later all seems okay.

tip: Sif cream cleaner brings the clear plastic up a treat.

[sparklingspirit]

I have had a bubble in my compass for the past 6 years. I had the local agents fill the compass (I don't know how they did it), but the compass leaked and I now have the bubble which doesn't get any larger. The compass works fine, so I have decided not to replace it.

[danciger]

Hi Gerlachm, I had same issue in my plastimo old unit on my 1989 Sun Shine 38. Here what you do :
Get some small amount 100-150 CC of mineral oil, or clear(!) oil they use to lubricate sawing machiens,very cheap and easy to get.
Get a small syringe from your medical treatment staff.
Pullout the unit very easy two screws.
With a screwdriver open the filling valve while placing it as upstairs as possible
Now,very tricky and delecate, press the rubber sphere slowly till the buble is pushed out off the open valve. now ,press in using the oil loaded syrgine back in some amount of oil to allow the rubber sphere back to it's normal size.you do not need a niddle !!
Try it,it works. matirials for the experiment simple and cheap.
If your compass don't leak it will keep ok for another 10 years, same happened in mine.
Enjoy
Alex