Cleaning a sextant

[Ross D]

I have just picked up a second hand Frieberger drum sextant with the allview lens, from what the seller was saying it has never been used, but it has been stored with the lid removed as an ornament for the last 30 years., so it's a bit grubby. Before I align the lenses etc I want to clean it up which includes the shading and lenses.

I'm after any advice on what to clean it with that won't damage the lenses, it's slightly greasy so water and a soft cloth isn't going to do the job.

Many thanks

 

[Frank Holden]

Same stuff as you use to clean your glasses. Works on greasy thumb prints on mine.

 

[Praxinoscope]

As Frank Holden has suggested, also you can use the stuff they sell for computer screen cleaning or thé impregnated spectacle cleaning tissues on the pharmacy shelves in the supermarket. I keep a ‘Selvyt’ cloth in the box with my sextant to clean it off after use, a small drop of Isopropyl Alcohol on the cloth won’t do any harm.