Wood boat deck

Discussion in 'Boat Design' started by Travis Grauel, Mar 8, 2020.

  1. fallguy
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    fallguy Senior Member

    I don't like that idea; too much potential for leaks. See prior post.

    others with more pof experience may respond differently
     
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  2. fallguy
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    fallguy Senior Member

    btw, my plan assumes you do not need a structural fillet and tape at the frame and that you used screws and glues to affix the hull to frame
     
  3. Travis Grauel
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    Travis Grauel Junior Member

    I drilled 1 inch holes at every frame at the keel...thanks for all the help
     
  4. fallguy
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    fallguy Senior Member

    Another option would be to foam it all in, but any water leaking down from a pinhole in the deck will rot out the area of the leak overtime.
     
  5. Travis Grauel
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    Travis Grauel Junior Member

    So I think my best bet it dry deck of plywood to a dry bildge in the back
     
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  6. fallguy
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    fallguy Senior Member

    When you deck the thing; build the deck all the way out to the hull or about 1/4" shy. Cleat the hullsides with 3/4"x 1.5" pine just below the deck. Template the work with cardboard from appliance store as each frame needs a cutout. Cleat the frames. For your cleats; only thixo bond them or tiny fastenings you can remove. Thixo bond the deck down and seam at the hull like I said. Be very careful at plywood seams to always have a tape at all seams. I precoat all wood 30-60 minutes before applying tapes; most woods will drysuck resins.

    For your hull, I think a 10 oz woven would be plenty. Your chine looks too sharp for the glass to round over. 1/4" min radius. Precoat 100% before laying a light woven or you'll be sorry.

    The transom is built entirely different. Disregard everything and get the transom planned before you deck.

    8687C161-DCC6-48A8-A1EC-02567DC0BDD5.jpeg
     
  7. fallguy
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    fallguy Senior Member

    This is my opinion, but I did say I am not real familiar with plank on frame.

    Also, please go back and reread my posts. Sometimes when we are too conversational; I realize an edit or clarification is needed and I go clean up my post; usually for grammar, but sometimes content.

    If you have any more questions, please
    PM me, I would like others to post.
     
  8. Travis Grauel
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    Travis Grauel Junior Member

    Awesome appreciate it!
     
  9. fallguy
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    fallguy Senior Member

    Please also explain your hullsides and bottom plywood seams.
     
  10. Travis Grauel
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    Travis Grauel Junior Member

    Seems have scab backer and glued and screws and will be taped
     
  11. fallguy
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    fallguy Senior Member

    Not a fan. These butt blocks are classic locations for rot. Those you ought to fillet all around, but honestly; a scarf is preferred.

    show the backer in a pic if you can; if they are not glued well; you could also remove them and glass them with 8" and four inch tapes

    I guess the word scab backer makes me a little nervous is all.
     
  12. bajansailor
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    bajansailor Marine Surveyor

    " I would like others to post."

    Fallguy, I think the reason why nobody else has posted yet is that you have done an absolutely grand job singlehandedly of helping Travis so far!

    Is a 'scab backer' a block over the butt joint in the plywood? Are they just glued with the waterproof glue with screws in addition? For the rest of your butt joints it might be preferable to use epoxy rather than just waterproof glue? Or as Fallguy says, use scarf joints in the plywood instead?

    Re the planks set into the frames just above the chine (a chine log?) and (I presume) at the sheer (a beam shelf or sheer log?) - will you be gluing and screwing the plywood fully on to these as well? Again it might be worthwhile using epoxy for the remaining joints, rather than wood glue.

    Will the boat be kept afloat on a mooring, or ashore on a trailer?
    I think it would be a good idea to aim for a dry bilge under the deck - but still have limber holes in all the frames to allow any water that does get in to be able to drain aft, and have a drain plug in the transom. This will be useful buoyancy as well. If kept ashore then check the bilge every time you haul out.
    This was the standard method of constructing Mirror dinghies in the 60's & 70's - we had one, and the plywood inside was not coated with anything, just left bare, and it lasted a long time. Although it would be better now if you seal the plywood inside your dry (hopefully) bilge.
    It would be good to also have some reserve buoyancy higher up (eg under the gunwhales) as well.
    Is it good quality marine plywood that you are using?

    The scantlings appear to be pretty substantial, re the 1/2" thick plywood and the fairly close frame spacing - the glass sheathing (preferably epoxy, not polyester!) should mainly be for abrasion resistance rather than having to contribute towards strength. With an added layer or two on the joints as required.
     
  13. gonzo
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    gonzo Senior Member

    I can help you, but first needed some information. If you epoxy the inside, there should be no problem leaving the space between the floor and the bottom of the boat as a sealed box. Most of the problems with wood is with hardware that is not properly bedded or the bedding deteriorated with time. Fully encapsulated wood will have an unlimited life.
     
  14. Travis Grauel
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    Travis Grauel Junior Member

    I got ya so you also think a dry bilge is the way to go?
     

  15. Travis Grauel
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    Travis Grauel Junior Member

    Thanks so I think dry bilge is what I’m shooting for at this point what fiberglass do you recommend for entire outside? Marine grade plywood I used is definitely not top of the line pretty far from it actually...
     
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