1980 four winns - wet transom

Discussion in 'Fiberglass and Composite Boat Building' started by atengnr, Nov 19, 2019.

  1. atengnr
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    atengnr Junior Member

    OK thanks alot for the advice. Mr E, I like your reasoning. Yes, it does have foam from the factory. So Mr E, if I do your repair suggested properly, and I know this is all my responsibility, but you would feel comfortable using this boat out on a big lake, on some rough water? Ill be running my 70hp Force (or 55 Johnson) at 30mph max on this boat.
     
  2. Mr Efficiency
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    Mr Efficiency Senior Member

    You could pack in some large chunks of buoyancy foam aft on both sides under the splashwell , too. If you were to replace the transom, it would only make sense as part of a re-build of all the timber inserts, and that is a big job, and not a very economic idea. I think if you throttle back in the rough, it should do OK, no airborne stuff !
     
  3. Blueknarr
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    Blueknarr Senior Member


    Single plane single color repaint no problem

    Multiple cross faded gelcoat graphics on contoured surfaces and around to the side hull at invisible repair quality. Time consuming
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    Obviously an unusual situation with that repair, and a customer happy to say ta-ta to his money !
     
  5. atengnr
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    atengnr Junior Member

    Thanks, yes this boat will not be airborne with me in it. I am willing to go offshore where I dont belong, but not while overstressing the hull.

    So where do I buy solid foam sections to place?
     
  6. Mr Efficiency
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    Mr Efficiency Senior Member

    Polystyrene will be OK if you give it a few coats of acrylic latex paint, in case you accidentally splash some fuel
     
  7. Blueknarr
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    Blueknarr Senior Member


    Why the solid foam?


    Isn't the transom cored with plywood? If so re-core with marine plywood.

    If only small section rotten, then only replace the rotted part.

    Are you needing to replace the post catastrophe buoyancy foam?
     
  8. atengnr
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    atengnr Junior Member

    I think it was suggested to add more foam, perhaps under splashwell
     
  9. Blueknarr
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    Blueknarr Senior Member

    What is the purpose of the new foam!
     
  10. Mr Efficiency
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    Mr Efficiency Senior Member

    Buoyancy. The stuff underfloor might not be up to spec after all those years
     
  11. Blueknarr
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    Blueknarr Senior Member

    Sorry about the "!"
    Fat fingers. Should have been a question mark.

    I want my buoyancy foam to kick in way before the splash well nears the waterline.
     
  12. atengnr
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    atengnr Junior Member

    Yeah me too! Doesnt the fact that I run a motor thats 1/2 of the boats max rating provide some protection against transom failure?
     
  13. Blueknarr
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    Blueknarr Senior Member

    The small outboard will produce only marginally less transom stress.

    Fix the transom.
    Then add foam. The lower the better. Cheap rigid installation from the box dyi stores is acceptable flotation. It is dissolved by gasoline and polyester resin. So, some hoops to jump thru.

    Expansion foam is also used. It will slowly absorb water and lose its effectiveness.
     
  14. atengnr
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    atengnr Junior Member

    Ok, how about cutting out rotted area in full thickness and tabbing in new wood? Good enough? I think i can do this without removing splashwell, cutting floor.
     

  15. fallguy
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    fallguy Senior Member

    usually the rot heads downward

    if you have no evidence of rot beneath the sole; I would never remove the sole without evidence of rot by tap test or removing garboard plug or other penetrations and verifying trouble

    tabbing in wood all depends on how much

    if you have a large area; tabbing vs laying a whole layer of glass to the hullsides seems a bit silly, for example
     
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