Paint on polyurea

Discussion in 'Boatbuilding' started by YD Marine, Dec 25, 2015.

  1. YD Marine
    Joined: Nov 2014
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    YD Marine Junior Member

    We are thinking of restorating a wooden boat which is applied 2 layers of plywood on the original cold molded hull and made too heavy.
    We want to remove the plywood, fair the hull surface, apply polyurea and paint on it. Is filler and paint applicable on polyurea.
    Regards,
    Yasin
     
  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Polyurea is an elastometer, so it will be really hard to find something that will work over it. What is the reason to use it?
     
  3. PAR
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    PAR Yacht Designer/Builder

    Most of the common polyurea's now on the market can be painted over, though the elasticity differences will usually cause the paint to crack and shear in time, if wide temperature swings are anticipated. Filler's elasticity can be adjusted, but paint not so much.
     
  4. YD Marine
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    YD Marine Junior Member

    Wooden hull was absorbing water before being covered with two layers Of plywood. Now she is too heavy to perform. Owner wants to renive the plywood ABD apply polyurea instead. But paint on it is an unknown subject for us. if it is not applicable do you know any alternative product.
     
  5. YD Marine
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    YD Marine Junior Member

    Sorry for typo. it would be; ....remove the plywood and apply ....
     
  6. gonzo
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    gonzo Senior Member

    If you mean it was leaking water, the polyurea will probably not fix the problem. Seems like the problem is at least caulking. It locks the planking and creates a structural panel of the hull sides. There may be fastener sickness and framing problems too. Usually, that kind of repair indicates serious problems.
     
  7. keith66
    Joined: Sep 2007
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    keith66 Senior Member

    It says she is cold molded, sounds to me if it needed covering in plywood in the first place it had problems to start with. Whats under the plywood now? rot?
     
  8. PAR
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    PAR Yacht Designer/Builder

    Look, the situation seems pretty obvious. You have a hull that wasn't repaired properly, so you can now remove the crap and do the job right, or look for another lousy solution, for a seemingly gullible owner. No goo in a can is going to fix this, even if the plywood is removed and the molded hull is permitted to dry out for a year. Simply put, a molded hull shouldn't need a plywood sheathing and if it did, it was a piss poor job. Repair the real issues, don't cover it up with something and hope for the best. At worst, some of the planking will need to be replaced and a relatively heavy fabric sheathing applied, to tie everything back down. At best, you'll find the source of the problem(s), let the puppy dry out, then effect the appropriate repairs and send it on it's way with fresh paint.
     
  9. YD Marine
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    YD Marine Junior Member

    Thanks for the realistic reply. I must say that i was not invovlved in the building or repairing process of the boat until this stage. I will see the boat soon and inform you better.some owners remember to consult naval architects after the problem occurs. I see that we should fix the original hull first and apply fiberglass on it and paint properly instead of putting sth on to sth faulty.
    But applicability of paint on a coating like polyurea is still a subject of question. I ordered a sample plate with polyurea to test. But a sample plate will not show what wil happen in years on a boat
     

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

    You can accelerate the aging of the polyure with intense UV lighting, cyclic heat/cool routines and some flexing. To save the bother, it will chalk up pretty quickly, but can be cleaned up with a plastics rejuvenator.
     
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