Repair of wet balsa core

Discussion in 'Boatbuilding' started by Onak, Nov 2, 2014.

  1. Onak
    Joined: Nov 2014
    Posts: 2
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    Location: Oslo, Norway

    Onak New Member

    I have a Farr395 built in 2001. It has balsa core below the waterline. Foam above waterline and in deck. The boat is not very well built with extremely thin laminates, and with the end wood not really saturated with resin. Anyway, teh core is wet. And i mean wet - not humid.

    This winter I had a damage in way of two supports during storage on land. Too much weight on the supports and too little on the keel. The hull came in a few centimeters, but the sandwich was of course delaminated. The damage is forward of the engine, approx. at the entrance to the salon.

    A repairshop is doing the repair. They have taken out the outer skin and the core of about 70 cm width from centerline and up to the waterline on both sides. This kind of splits the boat in two. They use a H100 divinycell core. The insurance company is paing for the repair. However. the section forward of the repair area is vey wet and the balsa is dark and has started to deteriorate. I am considering doing additional repair from the inside. I then want to take out sections of the innerskin and core. Strengthen the outer skin, add new divinycell core and add a new innerskin. In that process I will have to support the outer skin as it is very thin, to prevent it from buckling etc.

    Here comes my question: How do I support the outer skin in such a process? As a continuation of the engine bay two longitudinal girders are quite close to the centerline. They are resting on the inner skin. Would you suggest that I make a single skin in this area?
  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    You can do the repair in sections. That way there is no need to support the whole boat. The outer skin shouldn't buckle if the rest of the boat is well supported.
  3. Onak
    Joined: Nov 2014
    Posts: 2
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    Location: Oslo, Norway

    Onak New Member

    Thin laminates

    The outer skin is as thin as 2-3 mm. It buckles for sure if it is not supported. Any hints?

  4. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    If the boat is blocked up properly, the local area(s) where either the inner or outer skin needs to be removed will remain undistorted. This assumes the supports, stands or whatever they're using to block the boat aren't near these affected areas.
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