Old Gruen p.w. metal surface aging problem.

Thread: Old Gruen p.w. metal surface aging problem.

Results 1 to 3 of 3
  1. #1
    Member
    Join Date
    Nov 2009
    Location
    NW Boulder, CO. mts.
    Posts
    2,211

    Old Gruen p.w. metal surface aging problem.

    As an accumulator of old Pentagon Gruens (80-100 years ) I have seen new looking ones, but most have tarnished or oxidised movmnt. plate and dial surfaces. Before and after silver tarnish remover on movement photos here. But how to remove colorful oxidised films on gold alloy silver dial numbers without damaging silver?
    Attached Images Attached Images






  2. #2
    Member radger's Avatar
    Join Date
    Nov 2007
    Location
    N.E England
    Posts
    3,383

    Re: Old Gruen p.w. metal surface aging problem.

    I think those tarnished numbers look amazing, it looks like the colours you get on polished steel whilst
    tempering during heat treatment and also like the diffraction of light through a prism.
    I suppose, due to the silver content, these numbers will continue to darken given time.

    The numbers look to be mirror polished, I would suppose a skilled dial finisher could re-polish these.

  3. #3
    Member
    Join Date
    Nov 2009
    Location
    NW Boulder, CO. mts.
    Posts
    2,211

    Re: Old Gruen p.w. metal surface aging problem.

    I was just told simply a brief exposure to a liquid cleaner specific for gold washed off with water will not harm the printed letters and scales. Even if a very brief exposure to silver cleaner, quickly water washed, printing will be safe on silver dials. I am still insecure about silver dials having various lacquer and other passivating coatings. Heard of Some Gruens being platinized, whatever that means,

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

    Posting Permissions

    • You may not post new threads
    • You may not post replies
    • You may not post attachments
    • You may not edit your posts
    •