Timber dinghy resto - should I glass the hull?

Discussion in 'Wooden Boat Building and Restoration' started by Jamie King, May 13, 2017.

  1. Jamie King
    Joined: May 2017
    Posts: 2
    Likes: 0, Points: 1
    Location: Sydney

    Jamie King New Member

    Hi All

    I just picked up a free Mirror dinghy in Sydney, Aust.

    Ply hull is rotten and about 20% of it has been removed ready to re-ply. Cedar Bulkheads/frame seems to be in good condition.

    Hull is currently painted timber.

    My questions is should I glass the outside of the hull? It is currently about 4mm ply and pretty flexible in places between the bulkheads.
    My thinking is that it will make it stronger and more robust. Also, there is flaking paint so the whole thing needs to be sanded back anyway. Also, as I'm not much of a perfectionist, I am sure my ply timber patch job will be pretty average so it need bogging anyway.

    I don't really care about weight - boat will not be raced - its just something to play around in and teach my son how to sail.

    So what weight and type of sheet should I use?

    Any good resources online for a first-time fibre-glasser? (other than the odd surfboard repair)

    Thanks
    Jamie
     
  2. PAR
    Joined: Nov 2003
    Posts: 19,133
    Likes: 474, Points: 93, Legacy Rep: 3967
    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Welcomed to the forum.

    Applying a layer of 'glass over the light plywood isn't going to add any significant strength, nor stiffness to this hull. I'd recommend replacing the 4mm with 6mm. Without pictures to see what you're working with it's tough to offer much more, though replanking the bottom with 6mm will greatly stiffen things up, while not adding much weight. Usually the structural elements, (chine log, stringers, clamps, etc.) take a beating on these puppies and need to be renewed to return strength and stiffness.
     
  3. upchurchmr
    Joined: Feb 2011
    Posts: 3,008
    Likes: 143, Points: 63, Legacy Rep: 579
    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    PAR,

    You are probably right about the complete hull, given this is ply on frame.
    However, the ply will be significantly stiffened by even single sided glass (and epoxy) and can improve a less than perfect repair (20% replaced) depending upon the joints are made.
    There is not enough information to tell.
     
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