Sextant mirrors re-silvering

[Steamburn]

Dear member of the forum,
Does anybody know where in the USA I can send my sextant mirrors to be re-silvered?
My mirrors are starting to look a little sad.
Regards,
Steamburn

[P.Rutherford]

Steambum,

To answer you immediately, no, I don't know where or who to send it to. However, the maker of the sextant might be able to help you.

The index mirror on your sextant is a "first surface" mirror. You can buy "first surface" mirrors on Ebay and they are cheap.
If you're clever enough, you cant use a diamond wheel to cut the mirror so size. Glass cutting diamond wheels/saws are available for rent at Home Depot. A specific glass cutting blade/wheel will cut your mirror cleanly.

About 5 years ago I purchased a first surface mirror from SEETHROUGHMIRRORS.COM but they apparently are out of business. I think it cost me $10. Most mirror places can cut a mirror for you to any size.

The Horizon mirror will be more difficult as it's typically partially reflective. But....you might be able to employ the same method as I described above for a split horizon mirror.

Please let us know how it turns out for you.

Paul

[PeterB]

There  are several optical coating services for amateur telescope makers who should be able to strip and re "silver" your mirrors. Actually they don't call it"silvering" anymore since the use high performance coatings.  Search using "telescope mirror coating service"  Two that pop up in USA are Magestic-coatings and OWL (Optical Wavelength Labs)
     I have not used any of these services personally so I have no direct experience. It just seems like a logical place to start. They are used to working to the highest optical standards with customers who create their own astronomical telescope mirrors so they should be able to handle a sextant mirror.  A common complaint is most are not fast turn around.
    Another place to look for information might be the forum "Cloudy Nights" for amateur telescope makers (ATM's)
    Hope this helps. Let us know what you find.

It might also be possible to make replacement mirrors from standard mirror stock. That would depend on how fussy you want to be about the final accuracy. Standard mirror stock is made from float glass which these days is pretty good, optically speaking.  I did that for a not-so-pretty Simex sextant I had aquired cheaply and it worked out fine.
   PeterB