Plywood sectional barge

Discussion in 'Boat Design' started by GhostGeek, Nov 7, 2019.

  1. rnlock
    Joined: Aug 2016
    Posts: 72
    Likes: 4, Points: 8, Legacy Rep: 10
    Location: Massachusetts

    rnlock Junior Member

    I thought the ship can was a horrible idea anyway, but would it really rust that much faster in the water than it would near the water? Why take the doors off instead of weld across with strips of extra metal?

    I should have mentioned that the epoxy, if exposed to UV, should be painted. I have little doubt that 3/4 glass and epoxy, covered by paint, would be better than just paint. I'm not going to refrain from saying something is grey just because someone might willfully interpret grey as black or white.

    Meanwhile, light plywood with 3/4 oz. glass, painted white, might be just the thing to keep the container from cooking. And that would be above the waterline.

    gonzo:
    Would even Titebond III fail? I guess maybe we can't be sure.
    rumars:
    There are a lot of containers out there. Maybe just tow in a container full of sneakers that fell of a ship. I understand that a lot of them are out there. ;-} I'll admit I suspect that such a container isn't the best choice. Especially after that summer job bashing rust off a houseboat that was made from a tugboat. Ugh! Would be a great place to live if:
    1. Someone else removed all the rust and repainted on a regular basis.
    2. Someone invented hurricane repellent.
     
  2. gonzo
    Joined: Aug 2002
    Posts: 13,621
    Likes: 383, Points: 93, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    We can be absolutely sure that Titebond III will fail. It is not made for the application. If you have any doubts, glue two pieces of wood with it and then submerge them in a bucket of water.
     
    fallguy likes this.
  3. rnlock
    Joined: Aug 2016
    Posts: 72
    Likes: 4, Points: 8, Legacy Rep: 10
    Location: Massachusetts

    rnlock Junior Member

    I can guarantee you that if you don't wait something like a week before you test, it will fail. Per the label.
     
  4. gonzo
    Joined: Aug 2002
    Posts: 13,621
    Likes: 383, Points: 93, Legacy Rep: 2031
    Location: Milwaukee, WI

    gonzo Senior Member

    So, are you saying that building a boat that will only last a week is acceptable for you?
     
  5. rnlock
    Joined: Aug 2016
    Posts: 72
    Likes: 4, Points: 8, Legacy Rep: 10
    Location: Massachusetts

    rnlock Junior Member

    No. I'm saying that if you get it wet within a week, don't come paddling to me to complain about it.
    -------------
    Just double checked the label and I don't see anything about 7 days. Maybe that was Titebond II. Anyway, Titebond claims that Titebond III passes a Type 1 test. They describe it like this:
    Type I testing involves cutting the 6" by 6" assemblies into 1" by 3" specimens, boiling them for 4 hours, then baking the specimens in a 145˚F oven for 20 hours. They are boiled for an additional 4 hours, then immediately cooled using running water. The specimens are sheared while wet, and the bonds must pass certain strength and wood failure requirements to pass the Type I specification
     
  6. fallguy
    Joined: Dec 2016
    Posts: 2,171
    Likes: 144, Points: 63, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    Let's say the glue works on the usually wet on purchase treated lumber (another problem with the concept).

    You still have not addressed the end grains of the plywood. They will soak water the fastest against the pressure treatments best and swell. When they do, if we assume the glue survives; the glue will never be able to maintain a bond fully against the wood as the joint expands beyond the original dimension of the glue and does all sorts of odd things.

    This is one of the many problems with the idea.

    Titebond is fine encapsulated; otherwise; it will fail by the swelling nature of immersed wood.

    If you ever built a .6 pressure treated foundation; you'd know the joints must be sealed to cover end grains. Edges must be sealed with poly on a corner. The idea of constant submersion is entirely more difficult. The titebond will work, but only fully encapsulated and probably the inside as well.

    The reason these threads drift into polemics is because the idea is horrible and defending some small merit of the idea is simply too much for the mindful to bear.

    ....but Titebond is waterproof !!!!

    ....... not that waterproof
     
  7. Waterwitch
    Joined: Oct 2012
    Posts: 93
    Likes: 9, Points: 8, Legacy Rep: 20
    Location: North East USA

    Waterwitch Junior Member

    From the titebond website it says not to use it underwater or for structural applications.
    LIMITATIONS:
    Titebond III Ultimate Wood Glue is not for continuous submersion or for use below the waterline. Not for structural or load bearing applications.
     
    fallguy likes this.

  8. rnlock
    Joined: Aug 2016
    Posts: 72
    Likes: 4, Points: 8, Legacy Rep: 10
    Location: Massachusetts

    rnlock Junior Member

    Could be CYA. After all, if glue isn't good for "structural applications", it isn't good for anything, except maybe decoration if it's a nice color. Seems like if you can boil it for hours, it's probably pretty good.
     
Loading...
Forum posts represent the experience, opinion, and view of individual users. Boat Design Net does not necessarily endorse nor share the view of each individual post.
When making potentially dangerous or financial decisions, always employ and consult appropriate professionals. Your circumstances or experience may be different.