Friday, April 27, 2012

A Compass for ‘Sandpiper’ – Part 2


I was not disappointed with the Sowester Bosun compass I acquired by bidding at Ebay. I took a risk that paid off. When it duly arrived at my doorstep I anxiously opened the parcel to examine the compass which I knew full well had a large bubble under the glass. What I didn’t know was how to go about replacing the missing liquid. I didn’t even know what type of fluid it was. I gambled that liquid from an old, obsolete compass that I had no intention of using would be suitable.



After examining the Bosun compass I discovered that if I extracted two plastic-type screws from the outer side of the casing, the actual compass could easily be removed.  I immediately observed a large screw that plugged a hole through which I could replenish the liquid by using a surgical syringe. I undid the screw and administered the life-giving fluid. By gently rocking the compass a little from side to side I could release a few tiny bubbles that remained, and continue filling the bowl until full.

Regarding the nature of the liquid, it certainly was not gin! - More like clear, good quality paraffin, because of that fluid’s characteristic smell. I didn’t notice any difference in appearance or smell between the two liquids.  I assume they both have the same viscosity, and I trust there will be no ramifications if they do not.

Just now, I am very happy with ‘Sandpiper’s’ cheap, but practical compass. May that continue as I make use of this essential item.  

4 comments:

Bursledon Blogger said...

Bill Like you I think they are one of the best compasses we've had on a boat, especially as you can see the course from any angle unlike some of the bulkhead mounted ones.


Regarding the fluid it is a clear oil, a local compass adjuster told me to top up with white spirit which I've done over the years on many compasses and has always worked - although I guess it's always been less than 20% of the total fluid

Max

Patrick said...

The grid compass also makes it very easy for any helmsman to steer a reciprocal course in an emergency, without having to do any mental arithmetic.

That could be a life saver.

William Serjeant said...

Max and Patrick,

Thank you for your useful comments.

A reciprocal course to steer is helpful when sailing in shallow water where there's a possibility of going aground, because the way back to deeper water can be found without having to calculate a course.

Bill.

From Roy aboard GL said...

Hi Bill, I have also had the same compass since 1970, original maker name was Sestral. It has been with me on every boat I have owned, and without doubt is the best steering compass ever produced. Have never seen them recently. My next job is to get rid of the bubble that has developed since being in the Caribbean.
Roy
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