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: on washing sextants
    From: Courtney Thomas
    Date: 2004 Aug 3, 09:52 -0500

    Joel,
    
    I have a SNO-T with the barrel enclosed tangent screw.
    
    How do I properly gain access to the tangent screw ?
    
    Also, what should be done to preserve rubber eye cup pliability ?
    
    Appreciatively,
    
    Courtney
    
    
    
    Joel Jacobs wrote:
    
    > Peter,
    >
    > The most damage that befalls a sextant is due to living in a salt
    > atmosphere, particularly when used from small craft where they are subject
    > to frequent spray. Salt water, left unattended will first attack the
    > mirrors. The backside of the mirror's frames have a trough which collects
    > more of this spray then elsewhere and this starts to erode the silvering. In
    > time, it also will eat into any chrome parts, cause the paint to bubble and
    > lift on the frame. It will do major damage to a sextant with an aluminium
    > frame as salt water is a strong electrolyte.
    >
    > The prevention is to rinse the sextant in fresh water after each use,
    > whether its been subjected to salt spray or not. If the sextant has its
    > tangent screw encased in a barrel or cylinder like the Russian and
    > Freiberger sextants make sure to run a lot of water through it which will
    > keep the screw from freezing. Then of course wipe down with a soft cloth.
    >>From time to time, you may also add some lubricating oil to the tangent
    > screw for protection on those that are housed. This is not necessary on
    > sextants with open screws. Doug Royer recommends NYOIL.  Jared Sherman
    > recommends DuPont Krytox. I use what I have handy which is Vaseline and
    > Never Seize. The latter only on a tangent screw encased inside a barrel or
    > cylinder because it does stain.
    >
    > Doug some time ago wrote a message which went into great detail of how he
    > and others on his ship took great pains to clean their instruments and
    > protect them. One of his recommendations was the use of RainX on the
    > mirrors. Hopefully he saved that message and can re-send.
    >
    > I also would like to hear what Jim Thompson has to say. He has one of the
    > most comprehensive sites on the internet devoted to CELNAV.
    >
    > Joel Jacobs
    >
    >
    >
    > ----- Original Message -----
    > From: "Peter Fogg" 
    > To: 
    > Sent: Monday, August 02, 2004 10:45 PM
    > Subject: on washing sextants
    >
    >
    >
    >>Quoting Joel Jacobs
    >>..where I
    >>
    >>>was talking about washing a sextant after use.
    >>>
    >>Would Joel, or anyone else, like to go into a little detail about this
    >>
    > sextant washing idea?
    >
    >
    
    
    --
    s/v Mutiny
    Rhodes Bounty II
    lying Oriental, NC
    WDB5619
    
    
    

       
    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