Welcome to the NavList Message Boards.

NavList:

A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Message:αβγ
Message:abc
Add Images & Files
    or...
       
    Reply
    Re: Restoration
    From: Brad Morris
    Date: 2018 Sep 21, 19:30 -0400
    Hi Tony

    I had my mirrors re slivered professionally.  It was reasonably inexpensive and the results were pure perfection.  Effortless too.

    If you intend to do it yourself, then to answer your question about film thickness:  it wont matter, unless it is too thin!! The reflective surface is against the glass.  Extra material does not affect that surface nor the image quality.   In front surface mirrors, the reflective surface is furthest from the glass, and thickness variations affect image quality.  

    Hope this helps
    Brad





    On Fri, Sep 21, 2018, 6:10 PM Tony Oz <NoReply_TonyOz@fer3.com> wrote:

    Hello!

    Recently I got a C.-P.-based soviet sextant on a flee-market. Its' mirrors need re-silvering.

    All the info about the process relates to the DIY-astronomers silvering their DIY-mirrors - when they have to intricately polish the reflective surface because it is on top of the glass (rather than under it).

    Will I need the polishing step as well (and should I worry of an excessive silver layer thikness - which is a problem for DIY-astronomers because of the unwanted silver crystalisation)? The reflective layer on a sextant mirror is to be formed "underneath" the optically-flat glass.

    Or should I simply go the the reputable mirror shop for aluminium vacuum-coating?

    Please comment.

    Warm regards,

    Tony

    60°N 30°E

    View and reply to this message

       
    Reply
    Browse Files

    Drop Files

    NavList

    What is NavList?

    Join NavList

    Name:
    (please, no nicknames or handles)
    Email:
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.
    Email:

    Email Settings

    Posting Code:

    Custom Index

    Subject:
    Author:
    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site