NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Don't do this to a sextant
From: Henry Halboth
Date: 2006 Nov 7, 14:52 -0500
From: Henry Halboth
Date: 2006 Nov 7, 14:52 -0500
Hi Alex, I have, in the past, successfully re silvered mirrors in accordance with the directions in the 1909 Edition of Bowditch which do require the use of Hg. The later editions of this publication do not contain these directions, but I feel sure that some of the other earlier ones must include them. Until recently, I had some Hg in stock but frankly do not know where to buy it commercially these days; perhaps the lab at Perdue could supply you. At one time all the nautical instrument houses were able to handle mirror re silvering, the last I know of being New York Nautical Instrument, on Hudson Street in NYC. I recently spoke with the proprietor of a glass shop that also supplies mirrors commercially, who offered to cut mirrors for me to any size desired, but that, of course, did not include the split mirror generally employed as a horizon glass in the average instrument, but cannot speak to the optical quality of commercially made general purpose mirrors or their suitability for use in our instruments - this later might be a subject for ongoing discussion, as I would like to explore the use of mirrors as an alternative to Hg or oil as an artificial horizon reflecting surface. If you do not have access to a pub containing Hg re silvering instructions, I will be pleased to post them, as they are not lengthy. Regards, Henry On Mon, 6 Nov 2006 21:05:58 -0500 (EST) Alexandre E Eremenkowrites: > > > Dear Henry, > > On Mon, 6 Nov 2006, Henry C. Halboth wrote: > > > As long as there is no deformation, I believe restoraton to a > condition > > of serviceability is entirely possible. I have done so with > several old > > sextants/octants that have been missing a variety of parts > > Do you make/resilver mirrors yourself? > > I am currently shopping for an old vernier sextant, > mostly paying attention on the state of the arc, > frame, vernier and filters. > > The requirement that mirrors should be also in good condition > substantially narrows my choice. So I thought of trying to > learn how to resilver mirrors myself. > Can you give any advise on this? > > I have in mind a recipe from an old navigation book > which requires mercury and tin foil. > > Alex. > > > > > --~--~---------~--~----~------------~-------~--~----~ To post to this group, send email to NavList@fer3.com To , send email to NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---