Polysufide used in Cold molded boat?

Discussion in 'Boat Design' started by witzgall, Mar 30, 2007.

  1. witzgall
    Joined: Sep 2006
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    witzgall Junior Member

    Hi all;

    I am looking at another cold molded boat. This one is in immaculate condition, with amazing wordwork both inside and out - it was owner built in 1973. The fit and finish are top knotch and has been kept that way over the years.

    I do have a concern. The owner described the hull construction as using two layers of wood stip/epoxy, fasened with monel ring-nails. The third layer is bonded using Polysuflide and monel ring nails (To 1 foot above waterline), then epoxy, and then vecra cloth, and epoxy to fair. So you have a hull with two strip planked layers, and one carvel.

    Should I be concerned about the polysulfide in a 30+ year old boat? IS/was this common practice?

  2. witzgall
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    witzgall Junior Member

    nobody has anything to say?

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    FAST FRED Senior Member

    I guess no one has actually seen the results of such construction.

    On many early boats a layer of muzllin laid into white lead was used between layers. But these boats had fastenings holding the layers together AND fast to the boat.

    Weather your construction is similar???

    IF the hull looks great , with no signs of repair , it would seem a suitable test of time , for that level of service..

  4. Pericles
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    Pericles Senior Member

    There are single and 2 part Polysulphide adhesives.
    In your position I would seek the services of a marine surveyor.


  5. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    I wouldn't be too concerned about the polysulfide. It shows the builder was experienced and had the sense not to use polyurethane (on wood) below the waterline. This isn't a common construction method, but does follow similar building practices found before true waterproof adhesives and sealants were available. If possible, see if you can get at some of the polysulfide, like at a thru hull fitting. If it's still pliable there, it will likely be elsewhere. If it isn't, then you may have cause for concern and a deeper inspection should be used, possibly with core samples.
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