Bearing remetalling

A lot of applications in the marine industry are still making use of white metal bearings. White metal alloys are made of tin (Sn) and lead (Pb), with traces of antimony (Sb) and zinc (Zn) to give it better wear and lubrication properties.

Bearings of this type can be found in crossheads of large 2-stroke marine propulsion engines, generators, and stern tube arrangements. When these bearings wear out, the old white metal is first molten away and collected. The bearing shell or stern tube is then throroughly cleaned, and made ready to cast a new layer of white metal in.

For most bearings and stern tubes we use a centrifugal casting machine, as in the picture below. We just commissioned our machine 2 weeks ago, and did a few test pieces. The bearing or stern tube is placed in the machine, which keeps it rotating. Molten white metal is cast into the rotating bearing shell or tube assembly, and the centrifugal force ensures an even distribution across the surface.

After cooling, the bearing is pre-machined to almost the nominal size. With an ultrasonic testing device checks are being done to ensure a good bonding between the bearing shell surface and the white metal. Finally the bearing is machined to its correct size.

The machine in the picture is capable of casting bearings up to a length of 2.20 meters. The equipment in the top right corner consists of melting ovens, to prepare the white metal for casting.

remetalling-equipment-045_1.jpg

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About Stranded Mariner

Marine Engineer and passionate sailor and cruiser, working in the marine business in China.
This entry was posted in Marine Engineering, Ship Repair. Bookmark the permalink.

9 Responses to Bearing remetalling

  1. Deep C says:

    Thats an informative article.
    cheers!

  2. Thanks, glad you liked it.

  3. Pingback: Remetalling of stern tube bearings « Stranded on the Largest Island

  4. Harry says:

    Dear Sir ,
    May I know, Where can I buy this Centrifugal Casting Machine?
    Interested in buying it new or second-hand.
    Please let me know.
    Thanks
    Harry

  5. Jeff says:

    Dear Stranded Mariner
    We are looking to get a Bearing Housing RE-BABBITTED in the Shanghai Area.
    The Housing is approx: 570mm Dia
    Do you know of any reputable companies that can do this ?
    Kind Regards
    Jeff

  6. Please call if we can be of service: Fusion Babbitting Company offers its customers the finest rebabbitting services in the world. Characteristics that define our bearings are 98 to 100 percent bond to the bearing shell, use of only “virgin tin base babbitt”, centrifugal casting, precise machining, with careful hand finishing.

    Our Quality Assurance Department maintains certification to ISO 9001:2008
    We are a service company specializing in the rebuilding and manufacturing of babbitt bearings. Our staff has over 50 years combined experience in bearing rebuilding and manufacturing new. We offer 24 hour emergency service when required. We can centrifugal cast up to 60” outside diameter, and deliver a completely refurbished Babbitt lined bearing faster than any supplier today. All bearings are ultrasonic tested for bond. Please visit our website!
    There are many reasons to let a full time babbitt repair shop to do your bearing refurbishing!
    Sincerely Mark McKindley
    800-613-5118

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