Sealing/Painting A Plywood Boat

Discussion in 'Materials' started by jpierce, Apr 25, 2004.

  1. jpierce
    Joined: Apr 2004
    Posts: 3
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    Location: Virginia

    jpierce New Member

    Ok. Before I ask my question, let me set the stage so everyone knows what I am trying to accomplish here.

    My 12 year old son wants the 2 of us to build a flat bottom boat for fishing our local (no motors) lake. It will be used perhaps a dozen times a year.

    I have selected a design that I believe the 2 of us will be capable of building. It is basically a 10' punt with a 4' beam and 18" from floor to deck and 2 bench seats.

    I will be building the boat using exterior grade 1/4" plywood.

    My questions are as follows:

    1) Would increasing the sides to 24" increase or decrease the "tippiness" of the boat?

    2) Do you agree with the 1/4" plywood or should I use a thicker grade?

    3) Remembering that this will be a first boat for both of us and we have a very limited budget, what would be a good way to seal and paint the boat to give us a few seasons of good use on it?

    Thanks in advance for all the help. I know I am a complete novice at this so any help would be appreciated.
  2. jpierce
    Joined: Apr 2004
    Posts: 3
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    Location: Virginia

    jpierce New Member

    More Information

    Stitch and Tape on the seams ...
  3. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    Since you are new to this, I'd stick to the plans as closely as you can. 1/4" ply isn't much structure to prevent a foot going through if placed in the wrong place when entering or leaving the boat, does this design have frames? Closely spaced frames can over come thin planking. Personally I'd use 3/8" MDO or other marine grade lumber for the bottom, but follow the plans.

    Increasing beam (width) or freeboard (height of sides) can adversely effect the handling and performance of the boat. Without considerable experience, changes along these lines would not likely come out well. Small unballasted craft have an inherent stability limit. Most of us stop doing whatever is causing the uneasy feeling (like capsizing) and allow the boat to regain her feet, before we go over into the drink. Sometimes in sailboats it's unavoidable, but for a row boat most of the time, it's because we did something (like leaned over to get something out of the water) and as soon as we stop doing it the boat rights herself and we can exhale. You'll learn the limits of the boat pretty quick and not go over the line. It would be a good idea to intentionally heel (lean) the boat to see where it's point of no return is, where your point of no return is, how far before she starts shipping water and how to right her in the event it does happen.

    Since you're looking for a disposable boat, I'd forgo the epoxy and glass covering, typical of dry sailed craft. A good grade of oil based house paint all over the boat will protect it for some time. If you really care for the boat and keep after dings, scratches and the like that WILL occur from time to time with fresh paint, keep it covered and not full of leaves and water she should last quite a bit past the life you're asking. You could put glass tape set in epoxy down the chines and the corners of the boat, for abrasion resistance and improved water proofing, but this will add to the costs. I wouldn't tape the seams of the boat unless it was a tape and seam design (structure dependant on the taping of the seams for its strength) as it would add a bunch of goo willed work and costs to a boat expected to live but a few years. A good design will have rub strips down the centerline and a few parallel to it on each side of the bottom. These will take the brunt of the abuse and may need replacements after a few years.

    If a good grade of ply was used and she lived under cover except when in use the whole of it could be varnished. The varnish would need the same care as paint, renewal when damaged or looking old, but certainly could last a decade or more without going crazy with the upkeep.

    A lot depends on the design, your skills and most importantly (for any boat of any size) the care they receive after they're built. With reasonable care it could live until you have grandkids plying the same waters you and your son will.

    Good Luck,

  4. JR-Shine
    Joined: May 2004
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    Location: Vero Beach, FL

    JR-Shine SHINE

    I would at least coat it with a layer of epoxy, it wouldn’t take more than 1 1/2 gallon (about $70.00). It will make the boat last a lot longer. You can just put some cheap "porch paint" over the epoxy. I did this for a canoe, the paint I got at Wal-Mart for $7.00 a gallon.

    Joel Shine
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