Chainplates renovation

Discussion in 'Fiberglass and Composite Boat Building' started by peleg7, Feb 4, 2023.

  1. peleg7
    Joined: Feb 2016
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    Location: italy

    peleg7 Junior Member

    Hello, I am a proud owner of an Alpa 11.50, 7,000 kg displacement, 1977 sailboat. The chain plates are in stainless steel and are glassed between two bulkheads. Since after 45 years I think it's time to change them, but I can't extract them since they're resin-coated between the two bulkheads, I thought I'd follow this method. Saw one of the bulkheads in correspondence with the plate, extract the old plate and replace it with a new one of the same dimensions, Resinate the plate again with epoxy resin and on the external face of the bulkhead glue another thickness of plywood (maybe under vacuum bagging?) in such a way to make the structure more rigid. What do you think?
    Could it work?

  2. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    Hello Michele,
    Do you have any bolts as well securing the chainplates, or are they literally just fibreglassed in between two bulkheads?
    If so, what is stopping them from pulling out?
    If there are bolts, can you post a photo or two showing the forward and aft sides of the bulkhead, if possible?
  3. peleg7
    Joined: Feb 2016
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    Location: italy

    peleg7 Junior Member

    Hi, obviously the plates are bolted to the bulkheads. I post some photos of the two sides of the bulkhead and a phot of how the chainplate was glassed inside a half-bulkhead. IMG-1114.jpg IMG-0973.JPG IMG-0962.jpg IMG-0969.jpg IMG-0973.JPG IMG-0962.jpg IMG-0969.jpg

  4. Rumars
    Joined: Mar 2013
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    Location: Germany

    Rumars Senior Member

    Your proposed schedule will work. You don't need to double up the plywood, just scarf the new piece in. Use the chainplate bolting holes and a taped doubler to generate the clamping pressure. In order to cut the scarfs in place on the bulkhead you can use a template and a router. The alternative to a true scarf is a series of steps, if that's easier for you.
    If you have to some deckwork anyway, then you can move them a ply thickness and have them exposed o the bulkheads.
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