Kurt Hughes Daycharter 36

Discussion in 'Boatbuilding' started by Charly, Mar 10, 2010.

  1. sabahcat
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    Location: australia

    sabahcat Senior Member

    Google is your friend



    The bolded comments above are interesting, considering your ply has Lloyds Register plastered all over it

    [​IMG]
     
  2. CatBuilder

    CatBuilder Previous Member

    I can attest that this stuff is the real deal.

    I had this conversation privately, but here's the story:

    BS1088 requires all plies to be 1mm. Making a 3mm sheet, you need to have some glue in there as well, so you can't possibly have 3mm of wood plus glue come out to a panel 3mm thick.

    For this reason, the face layers are thinner than 1mm and therefore do not meet specific BS1088 standards (not that there is any regulating body checking BS1088).

    it is because of these thinner layers that 3mm plywood cannot be true BS1088, but the source of this plywood above does indeed manufacture it to all the other BS1088 standards, excepting the thickness of the layers. So, they still stamp it BS1088 because it's made the same way as all the other, thicker true BS1088 plywood is. The say on their website it is BS6566 just to be sure, but it is made to BS1088 standards. (I have a sample right here)

    Also, this is good stuff... it's from a Lloyd's approved manufacturer.

    This is excellent plywood, pictured. My concern on my own Kurt Hughes build was that this plywood may be a little too stiff and it's definitely a little too pricey. However, I may go with it.
     
  3. uncookedlentil
    Joined: May 2008
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    Location: Olympic peninsula Washington

    uncookedlentil Junior Member

    gorgeous first panel all that extra curve in the stern bilge area and flatter bows is going to take a lot of sweat out of your fold-up.

    Kurt's done an excellent job on development of this technique
     
  4. keysdisease
    Joined: Mar 2006
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    Location: South Florida USA

    keysdisease Senior Member

    Hello Charly,

    Are you going to take passengers out for hire on this boat? Here in the US? Have you contacted the Coast Guard inspection Office?

    Any vessel taking over 6 passengers for hire in the US has to be a USCG Inspected Vessel.

    Steve
     
  5. CatBuilder

    CatBuilder Previous Member

  6. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    Hi Steve,

    Maybe. It depends on if we still have a government when I am finished:)

    Where are you in the keys? I spent most of the eighties living on the hook down around Card Sound. I miss those "Havey's special" grouper sandwiches down at the pilot house in KL.
     
  7. Charly
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    Charly Senior Member


    Hey Catbuilder, I learned a hard lesson today. These panels will buckle and break.

    My garage is long and skinny. There is room to do the panels, etc, but they have to be moved around. My buddy came out this am to help me move the first panel off of the mold so we could cut the next one. Notice that the bow section is almost flat, with little curve in it at the forefoot. When we tried to pick it up, it buckled a foot or so aft of the stem. It was a major freak out at the time, but I am over it now. I put a couple of "splints" on it, and immediately laid up a section of cloth on the topsides about 16 inches square above and ahead of the developing crack. We then stood it vertical, curve side down, until I can figure out what to do with it next. I will post some pics of it tomorrow, when I can get to my other computer.

    These panels are heavy to move around. I really should have had four people minimum to safely move it -- we should have done it "pallbearer" style instead of picking it up on the ends.
     
  8. CatBuilder

    CatBuilder Previous Member

    Oh my GOD I would have had a heart attack. So sorry to hear that.

    They pick those panels up in the video by the ends without any trouble. Do you think it was the heavier plywood you used? I just ordered the same stuff. It was heavy as compared to some other plywoods I was testing.

    Are your panels ultra heavy, or were they just (for some reason) more fragile than expected?

    Possibly another void causing the buckling?

    Either way, this is something to fully explore and Kurt should know about this too. Can't wait to hear the report and very sorry to hear that the panels buckled.

    One other thought: I recall you saying it took 36 gallons of epoxy to do all of the panels (9 for each panel). Using the construction manual, Kurt suggests it takes 30oz per 8x8 panel. I did the math and figured I'd need about 25 gallons (buffer included) to do my larger boat. Did the Raka "medium thickness" epoxy go on kind of thick compared to the video?

    Grasping at straws here, but very curious.
     
  9. uncookedlentil
    Joined: May 2008
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    Location: Olympic peninsula Washington

    uncookedlentil Junior Member

    yes to pallbearer pickup and carry panels with ''upside down bowl'' profile

    kamanu sister ship required 2 at 36', 4' tall panel. 42' with 6' tall panel required 4
     
  10. Charly
    Joined: Dec 2009
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    Location: st simons island ga

    Charly Senior Member

    Here are some pics from yesterdays calamity.
     

    Attached Files:

  11. Charly
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    Location: st simons island ga

    Charly Senior Member

    oops. some of those were previous pics
     

    Attached Files:

  12. hoytedow
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    hoytedow Wood Butcher

    Ouch!
     
  13. Charly
    Joined: Dec 2009
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    Charly Senior Member

    It happened in a predictable spot. The sudden failure oocurred at the bottom of the panel where there is a very slight curve. The top half of the panel, being almost flat, merely flexed, it did not break.
    before cutout, these panels all have the full curve, end to end, which gives them plenty of rigidity, but after the cutout, the bow ends are almost flat, and narrower. Live and learn. The plywood is 3mm, 3ply okume, and at the break, I did not see any voids inside. The break did occurr at a vertical scarf joint, on the middle ply. It could have been a bad scarf, but I don't think that is the case.

    Now to fix it.

    I would very much appreciate all inputs here. Let me start with my idea, and please feel free to critique or add on.
    I am thinking I should rout out two layers of ply, on the inside of the panel, with the middle layer routed back away from the crack several inches, and the inside layer routed back even more, to create a "stepped" canyon. Then glue in some dutchmen. and then maybe overlap and cover the whole thing with some triax. Fair and fill outside. The outside will eventually be covered with cloth anyway. maybe I should drill a hole at the end of the crack, and fill with bog?

    Another thing: most of this crack is in the bilge, which will be covered by a keel timber, embedded in structural bog, and coved in with three layers of 20 oz biax .

    I cant be thankful enough for all your willing advice, and my good fortune to be able to access and make use of it.:)
     
  14. hoytedow
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    hoytedow Wood Butcher

    Your repair plan sounds good, and with the timber re-inforcement, I think you will have no worries.
     

  15. Charly
    Joined: Dec 2009
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    Charly Senior Member

    I think the plywood weighs 11lbs/sheet. Ill have to check that. If so, that is about 20lbs/panel x 15=300lbs. the cutout only removes about 10%, so the whole thing probably weighs about 270.

    in the video, I think those guys were picking up an ama, which would be lighter, and with maybe a little more curve in it?

    I used probably eight gallons per panel. maybe 7, after the drippings etc. As I am a novice, I don't have anything to compare the viscosity of the resin to, so that is hard for me to say. I did make the conscious decision to put on enough resin, even if it meant a little too much, but I did try and follow the examples in the video.
     
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