boat stuck in mould

Discussion in 'Fiberglass and Composite Boat Building' started by whacker82, May 25, 2012.

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  1. whacker82
    Joined: Sep 2011
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    whacker82 Senior Member

    i have a boat mould and the boat is stuck in the mould by the stem, ive pumped water into it and the back rises with ease, its cought at the very front, im thinking where the keel meets the stem. i dont have an air compressor so thats out of the question, any ideas would be greatly appreciated.
    also she got 7 layers of mould realise wax and i made sure to put plenty in around the angles. thanks again
     
  2. TeddyDiver
    Joined: Dec 2007
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    TeddyDiver Gollywobbler

    Just bang the boat hull with a rubber hammer so the water btw the hull and mold should do the job. Can take while.. a day or two, never knows..
     
  3. SamSam
    Joined: Feb 2005
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    SamSam Senior Member

    I'm not sure about banging on anything. Did you use PVA? Water dissolves that, and getting water to it may take awhile. Has the mold ever been used before? (I ask, since maybe there is no draft to the mold where it's stuck.)
    First I would loosen up the sides and everywhere else that's possible, using reasonable force. Then I would put some lifting pressure on the hull where it's stuck, with wedges or a block and pulley, and let it sit overnight or so with some pressure on and see what happens.

    After that, if it doesn't come out, you have to get it out trying to do as little damage as possible, obviously. Even pressure instead of just ripping it out. Like at the point of the bow and a few other places on the sides, with some lifting at the back too, instead of just a crow bar at the bow and brute force.

    Sticking isn't too unusual, it sounds like it will come out without too much damage.

    I'm thinking if you put enough water in to float the back up a ways, and then push it back down with weights or clamps, that will put lifting pressure on the front and pressure on the water to get it into where it's stuck. Then leave it overnight.

    But actual lifting the front area with pulleys will do more.
     
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  4. variverrunner
    Joined: Dec 2009
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    variverrunner Junior Member

    Whacker,

    How big is the boat? Try pouring really soapy really hot water between the boat and the mold, and then let it soak overnight. It has worked for me in the past.

    Good luck

    Allan
     
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  5. Petros
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    Petros Senior Member

    I think applying heat to the assembly would help, use water as Allan suggest. If that does not work, try applying heat to the outside of the mold, and cooling the hull with cool water on the inside of the hull. Might expand the mold enough to get it free.

    Good luck.
     
  6. variverrunner
    Joined: Dec 2009
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    variverrunner Junior Member

    Whacker,

    Did you use PVA? The soapy hot water would work best if you did.


    If you didn't, I would try throwing a tarp over the works and use a small space heater to (not to exceed 120 degrees F or your epoxies TG) to accelerate the full cure.

    8 hrs should be more than enough. Then I would very very lightly tap the outside of the mold.


    Good luck

    Allan
     
  7. whacker82
    Joined: Sep 2011
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    whacker82 Senior Member

    thanks guys. whats pva? the mould is old enough mind and this is my second one that im pulling from it. the first one came out no bother just stuck on this one. im setting up a jig to hold the boat up and some weights on the mould to pull it down, ill get some hot soapy water i think after that and leave it over night.
     
  8. hoytedow
    Joined: Sep 2009
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    hoytedow Carbon Based Life Form

    If you could get the water between the hull and mold to freeze it should cause it to pop loose.
     
  9. Saildude
    Joined: Jun 2011
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    Saildude Junior Member

    It's mold release agent - makes parts come out easier - keep things from sticking to the mold
     
  10. Frosty

    Frosty Previous Member

    Dynamite should jar it loose.
     
  11. mydauphin
    Joined: Apr 2007
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    mydauphin Senior Member

    If all that fails drill a hole or twin in mold or boat bottom, epoxy in some air plugs, hook up your air compressor an raise pressure slowly. I had to this to a mold that guy did not put enough pva.
     
  12. whacker82
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    whacker82 Senior Member

    plenty of pva gone in made sure of that.
    what ive done is rose up the back of the mould and clamped the bow of the boat using vice grips, i also lifted this up only about an inch or two compared to the transom 10. put in a few buckets of warm soapy water. so the water goes to the front of the boat putting downward pressure on the mould, and the vice grips putting up ward pressure on the boat. im gonna leave it over night and see how it goes, fingers crossed. im off to the beer garden, been a long day. ill let ye know what happens in the morning. thanks again for all the imput
     
  13. TeddyDiver
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    TeddyDiver Gollywobbler

    Thumbs up...
     
  14. Herman
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    Herman Senior Member

    If there is PVA, then it will dissolve in water. Can take some time (a day, 2 days) but adding water regularly should be enough. No whacking on parts or moulds, which cause more delay due to repairs than just waiting for the part to come loose.
     
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  15. whacker82
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    whacker82 Senior Member

    still hanging :(
     
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