Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 71,806   Posts: 1,581,387   Online: 1090
      
Page 2 of 2 FirstFirst 12
Results 11 to 18 of 18
  1. #11

    Join Date
    Sep 2011
    Location
    Adirondacks
    Shooter
    Multi Format
    Posts
    3,655
    Denis,
    If you have an auto mechanic's supplier in the neighborhood, see if they have any fine valve grinding compound. There are two basic types, grease based and a water soluble base.

    I'd have mentioned this sooner but I was distracted.

  2. #12

    Join Date
    Jul 2012
    Location
    North Yorkshire, England
    Shooter
    35mm
    Posts
    724
    Years ago I made a ground glass screen for a Medium format camera by getting two pieces of glass the right thickness and the same size and actually rubbing them together with fine white quarz sand between the sheets. A little water was added and the whole process only took 30 mins. The biggest problem is getting it even at the edges. This med format Rollie look-a-like still has one of the screens I made and it is working fine (although not very often now).

  3. #13
    Marek Warunkiewicz's Avatar
    Join Date
    Sep 2008
    Location
    Toronto, Canada
    Shooter
    Medium Format
    Posts
    142
    Images
    11
    This is really good stuff, cheap as can be and very, very fine. Used for making telescope lenses and mirrors.

    http://www.willbell.com/ATMSupplies/ATM_Supplies.htm

    Marek
    Marek Warunkiewicz

  4. #14

    Join Date
    Apr 2004
    Location
    Montgomery, Il/USA
    Shooter
    Multi Format
    Posts
    5,299
    Any astronomy hobbyist site should be able to direct you to telescope making supplies.
    Heavily sedated for your protection.

  5. #15

    Join Date
    Dec 2004
    Location
    San Francisco
    Shooter
    8x10 Format
    Posts
    1,100
    Images
    127
    I'd be happy to send you some of mine, just PM me.

  6. #16

    Join Date
    Dec 2005
    Location
    Toledo, Ohio
    Shooter
    Medium Format
    Posts
    142
    Images
    4
    Any motor rebuilding shop (or factory maintenance shop) will have a small can of lapping compound around which is a fine abrasive paste used to polish or lap valves and other finely machined mating pieces to improve the fit or whatever. Perhaps they would give you a little for your project. Clover Lapping Compound (mentioned above) is a popular brand in the US. It may be available everywhere?

  7. #17

    Join Date
    Dec 2005
    Location
    Toledo, Ohio
    Shooter
    Medium Format
    Posts
    142
    Images
    4
    Dennis, another thought would be very fine 3M sandpaper used to repair auto paint. Any supplier that sells auto paint will carry sheets ranging from say 1000 grit up to about 2000 grit (at least in the US). Again, it is not an expensive product. Here you can buy 1 small sheet at a time for say $1.00.

  8. #18
    mjs
    mjs is offline

    Join Date
    Mar 2005
    Location
    Elkhart, Indiana (USA)
    Shooter
    Multi Format
    Posts
    1,107
    Images
    2
    If you can find a local amateur telescope maker who grinds their own mirrors they could probably help.

    Mike

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin