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
    Cleaning and protecting my Freiberger
    From: Renee Mattie
    Date: 2004 Aug 30, 14:19 -0400

    I have just bought myself a Freiberger drum sextant,
    used, made in 1976. I am happy with its overall condition.
    It works well.  Other than a few scratches in the middle
    of the frame, nothing looks terribly worn. I want to start
    out on the right foot with it, of course.
    
    If anyone has any tips or warnings to offer on disassembling
    and reassembling this sextant, I'd really appreciate learning
    more about it.
    
    Why would I want to do this?  There is a small amount of corrosion
    on some of the screws.  I think the thing to do is to remove
    the scope, mirror, and shade assemblies, wash the sextant
    to remove particles, the completely disassemble it for a
    more thorough cleaning, coat the non-moving parts
    (including screw threads) before reassembly to prevent
    corrosion, and lubricate the moving parts.
    
    So far, I have only been bold enough to remove the handle
    by unscrewing the upper leg stub and the large lower
    screw.  I see a waxy substance in the screw holes.
    I have no way of knowing if it was ORIGINALLY waxy,
    or if this is a grease that has gone waxy with age.
    In this forum, I have seen the following recommended
    for protection from galvanic corrosion:
    * Never-Seize
    * Lanocote
    * TefGel
    * Krytox with corrosion inhibitors(which Jared Sherman
    frequently recommends highly for a number of reasons)
    
    I don't see any recommendations for:
    * Hydrophobic dry coatings (like sailkote, which contains Krytox)
    and I wonder why.  Jared Sherman is of the opinion that these
    spray-on coatings just don't last very long.
    
    I am eager to take the sextant apart, but I want to be
    prudent.  I understand how to create a proper workspace,
    label and lay out each and every part, put screws back into
    same holes they come from, and take pictures along the way
    to remind me what it ought to look like when I'm done.
    
    It's just that I've never done this before, and there is no
    shop manual.  It looks like a straightforward job, but I
    really would appreciate hearing more from anyone who can
    give me a heads-up on any stupid thing a beginner is likely
    to do wrong.
    
    And I am up in the air about what to put on the screws before
    I put them back in.
    
    Thanks for your help!
    
    Renee
    
    
    

       
    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