Compass bubble

On Anna, we have a pedestal compass, marked “Henry Browne & Sons, Barking & London, Sestrel, 17854IV”. Late 2014, a bubble, about 40mm in diameter, suddenly appeared in the compass. A small bubble is not a big deal, but this was sufficiently large to make me worry about possible condensation in the air space. Also, filling a compass is done in a matter of minutes, right?

After researching what to fill the compass with I tried to find Isopar (M or L); no luck. So I settled for petroleum paraffin (C10C13), which is sold as lamp oil. The often recommended baby oil is not suitable (and in any case more expensive) as it starts to go opaque below approc -15 degrees C; it’s not often that it gets that cold in southern Sweden, but it happens.

Looking back, this is how the work went:

  1. Remove bow thruster control panel (to get to the screws holding the ‘steel cage’).
  2. Remove steel cage surrounding compass (to get the compass out of the pedestal).
  3. Remove compass.
  4. Clean and epoxy holes in pedestal for steel cage (had started to work loose).
  5. Drill new holes in epoxy, once hardened.
  6. Sand and varnish teak trim surrounding compass.
  7. Remove old varnish on steel cage and polish.
  8. Scrape, sand, prime and paint compass cover.
  9. Polish out scratches from compass dome.
  10. Make gaskets to fit between steel cage and pedestal. Hopefully prevents it from working loose in the future.
  11. Solder new red diode onto compass night light cable.
  12. Fill compass.
  13. Refit compass, steel cage and bow thruster control panel.

Again, never think about how much work it will take to fix something on the boat. Just do it!

No, baby oil is not a good idea, at least not in Scandinavia. After half an hour in the freezer, it went from clear to slush.

No, baby oil is not a good idea, at least not in Scandinavia.

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The oil was simply poured into the hole.

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Might as well touch up the varnish on the teak trim. Steel cage can be seen bottom left.

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And better scrape off that loose paint on the cover.

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And those holes are starting to get bigger, making the steel cage a bit loose. Better expoxy them. And those non-matching screws have to be fixed.

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And the new epoxy-PU paint on the dome cover doesn’t want to harden, so it goes in the oven.

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This stuff, Xerapol plastic polish, bought from www.svb.de, works great to polish out minor scratches

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And a new diode, instead of the old and burnt-out bulb, gets soldered onto the night light cable (the cable should be twisted to prevent interference with the compass). Almost done now…