Sestrel Grid Compass refurbishment

[Frank Holden]

I have/had a Sestrel grid compass circa 1960.
Having sat on a bookshelf ashore en mi casa for 30 years the grid bit - dunno the proper name - is no longer free to rotate so you can't align the grid with the card. Some sort of dissimilar metal issue or maybe just salt crystals.
Any thoughts on how to free it?
I truly am asking for a friend. He has recently aquired my old Vertue that I sold 30 years ago. I dropped off a load of bits two days ago including this compass.
Any help very much appreciated .

 

[burgundyben]

Argh. Old man Robinson the compass adjuster in Hamble used to do a lovely job of refurbing these but he passed away.

Sorry, no help!

 

[sarabande]

Is it the plastic one, or the metal/brass one please ?

My inclination (joke) is to pour water over the grid and see if you can dissolve any salt for a start. Increasingly warm water.

If that no workee, then dive into Youtube, where a number of skilled and less skilled people have a go at removing the bezel and restring to functionality.

https://www.youtube.com/results?search_query=sestrel+compass+repair

Best of luck !

 

[Daydream believer]

I refurbished one just before covid struck & made a set of gimbals as well. assuming the OPs is the same the compass is held in an outer ring by 4 small metal retaining plate. Each of these has 2 screws. Mine can be seen where one of the screws stands up as a tall black one. I did this so the black screw could be removed, the locating plate rotated & the bowl dropped free.
The owner will have to remove the 2 screws from each plate, . They will probably shear off. Then drill them out & tap them for 3mm metric screws. The bowl has a groove under the graduation dial ( both my grid compasses are plastic) & this groove can be cleaned with a pick but really the bowl is best removed & the groove can then be brushed out properly
This is a picture of the finished job. I did an article that was published in PBO, but I cannot recall when

 

[Frank Holden]

Thanks for the replies, I shall pass them on. This is a metal one with the 'T' grid so you can't sail - or fly - on the reciprocal. Same same this one https://i.ebayimg.com/images/g/ZYMAAOSwbQFk7OLz/s-l500.jpg and this one Sestrel compass, gimbal mounted In mahogany veneered wooden box