Sestral Moore Major II Binnacle compass problem

[john_q]

I have a Sestral Moore Major II Binnacle compass, the Quadrantal Correction version, see link http://www.sirs.co.uk/marine/major fitted to my steel yacht which is currently in a ship yard in Guatemala, Central America.

Anyway my problem is that the Quadrantal Correction system AKA “Kelvin’s Balls” have “somehow” managed to get broken whilst in the Yard.

It appears that the stud inside the Balls have been broken off and the balls are split open along the horizontal axis.

I have tried to contact Sirs (who refurbished the compass for me in 1993) via email 3 times but have had no reply – they still in business?

What are my options, can they be repaired, if so how?

If not, anyone know where can I get new or replacement ones?

 

[PuffTheMagicDragon]

If you still have the pieces you should be able to hold them together mechanically (e.g., welded) or else if there is a foundry nearby you could have them make replicas. As long as the mass of metal is there and the shape is more or less spherical, I don't think that it matters much. You would still have needed to adjust them and re-swing the compass anyway. IMHO.

 

[VicS]

They seem a bit elusive.
See this thread from last year http://www.ybw.com/forums/showthread.php?t=240805

I was going to suggest phoning but then noticed your location.

 

[john_q]

If you still have the pieces you should be able to hold them together mechanically (e.g., welded) or else if there is a foundry nearby you could have them make replicas. As long as the mass of metal is there and the shape is more or less spherical, I don't think that it matters much. You would still have needed to adjust them and re-swing the compass anyway. IMHO.

As I understand the balls are made of "non magnetic ferrous material" If I weld them, will it leave them magnetized?

Full understand about having to re adjust the compass as we have had a load of welding done - always good for a 40 degress + error

 

[PuffTheMagicDragon]

As far as I know the spheres are made of 'soft iron' which is non-magnetisable (unlike steel). I doubt that welding / brazing / silver soldering would alter their magnetic characteristics. If they split into two parts as I understand from your original post, I would suspect that they are merely cast iron. The mass and the spherical shape will still be there even if you used superglue to hold them together. As we said before, they will be shifted in any case until they (i.e., their mass and their shape) provide the required correction. I don't think that either one of those two factors is critical; any differences will be taken care of by the new positioning. Remember that we are dealing with old technology here, even if it is still valid. Always IMHO and subject to correction from the professionals.

PS: At the risk of teaching grandmother to suck eggs, may I suggest to have a look at this book:

http://www.scribd.com/doc/66715050/6/CHAPTER-VI

For $5 you can download it. Very convenient, especially if you have a Kindle thingy on board. Maybe you'll get one for Christmas?