The 18 Foot SeaSled

Discussion in 'Fiberglass and Composite Boat Building' started by Darkzillicon, Jan 23, 2023.

  1. Darkzillicon
    Joined: Jan 2023
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    Location: Palm Beach

    Darkzillicon Senior Member

    Thanks, I'm working on some drawings that should make things a bit more easy to see what im doing. The designer specified a 90hp outboard. I was expecting to go with a Yamaha F90 ... approximately 370 pounds.
     
  2. Darkzillicon
    Joined: Jan 2023
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    Location: Palm Beach

    Darkzillicon Senior Member

    While I am working on drawings I thought this view might be entertaining. There is a StemPlate to tie the two stems together out of Douglas fir plywood. This has stringers laminated on the topside and then the planking is put over that. Obviously it needs more joint clamping and miscellaneous but this is how it stands currently.

    I have been reading about how some of these designs "burp" air and spray and I am wondering if a trapped air duckbill valve might handle overpressure in the tunnel. This may allow you to get away with a less fine entry. Just a very quick thought.

    Bow View.jpg
     
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  3. Darkzillicon
    Joined: Jan 2023
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    Location: Palm Beach

    Darkzillicon Senior Member

    If you were wondering about the gap between the Upper and Lower Plate it's because of the way the deck stringers are attached. The two stringers on the far outside (the sheer clamp) are to be sanded down and wrapped with glass on both sides to they are more of a suggestion right now.

    The purple goop in the crack is fairing filler as the two pieces are fairly well bonded with epoxy on both sides. The Foredeck will then have 1708 on top so it will be sort of a monohull with the sides. Lots of tabbing and glasswork to be done inside as I close it up.

    How the Lid was Put On.jpg
     
  4. Darkzillicon
    Joined: Jan 2023
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    Darkzillicon Senior Member

    I have attached the plans. These are not the drawings that I made from these originals, but they are the plans that I built from. Only Frames #1,2 and the stem are slightly different. @BlueBell suggested that I upload them so here they are. I dont think there are any copyright issues as they are old as dirt and obviously someone else copied them.
     

    Attached Files:

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  5. Darkzillicon
    Joined: Jan 2023
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    Location: Palm Beach

    Darkzillicon Senior Member

    Made a quick scaled drawing of the top-down view. If my fuel tanks were infinite volume a.k.a no sidewalls or structure just the full volume 9,240 in3 occupied by fuel it would be right at 40 gallons tucked up under the gunnels like that in 24" high saddle tanks. I would consider this a best-case fuel load scenario with a 90hp outboard running full bore 6.5 gal per hour at WOT... Gives me 12.3 hours of WOT time. This is probably excessive for this small of a boat but just wanted to see people's thoughts on the fuel load etc. Since this boat is a sea sled the flat deck doesn't leave much room for fuel and I think the back gunnel area should be flotation foam to allow for full upright floatation of the boat in the event of the worst. This is just an initial idea. I am still thinking about where people should sit how the rear of the boat should be organized etc.

    That would be 500 pounds of fuel at 6.25 pounds per USA gallon.

    SCAN0000.JPG
     
    Last edited: Feb 1, 2023
  6. Darkzillicon
    Joined: Jan 2023
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    Darkzillicon Senior Member

    Starting to install the transverse bulkhead for the forward bench seating. Started with some epoxy fillets. Tape and glass to follow. 50D6BDA9-AA4F-4661-A13D-053CFFFCCFFF.jpeg
     
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  7. Darkzillicon
    Joined: Jan 2023
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    Darkzillicon Senior Member

    To get the complex curves on the foredeck, it took a little bit of creative clamping. Once the epoxy cures, I can remove the clamps shave off a bit more wood, and then add some more glass.

    60869DEF-C399-4523-966B-0E9B8A4B170F.jpeg
     
  8. Darkzillicon
    Joined: Jan 2023
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    Darkzillicon Senior Member

    I’m going to let the epoxy cure more overnight. I removed one clamp and shaved the sheer clamp flush with the deck. Same as the other side and filled the void between the deck and the clamp with 404 high density filler(cabosil).

    6B3680F0-0246-40D7-9758-6C5F66E61F64.jpeg
     
  9. Darkzillicon
    Joined: Jan 2023
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    Location: Palm Beach

    Darkzillicon Senior Member

    Sorry for the lack of updates. I had a minor surgery, and I was unable to do anything physical for about a week and a half so I didn't get much done. However today the sun was out the weather was clear and so I decided to make some progress on the Sled.

    Today I added the 1708 to the starboard side of the bow/foredeck. Decisions to make here include what the rake of the windshield will be.

    1. Do I want to give up room on the bow to have a really sleek rearward raking windshield that will make the boat impossible to pilot at night? 60 degrees is optimal.
    2. Yamaha 90hp Outboard should give me only 45 mph and aerodynamics don't really come into play till about 55-60 mph. so maybe I get away with the forward raking windshield.
    3. In fantasy world I would like to have a cushion on the bow for some lounging on the hook in nice weather, so too much windshield rake would take that away from me.
    4. Need to decide on the location of a rope locker access hatch and find one that I am happy with the looks of, I don't want an aluminum work boat one and I don't want a crappy plastic e.g. one from Dickson marine.
    In other news I'm working on some designs for the forward storage drawer unit in the cabin. I'll probably post those when I am happy with what I have come up with.
    bow glass.jpg
     
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  10. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell . . . _ _ _ . . . _ _ _

    80 degrees fahrenheit? (~27C)
    Sunny, door open... must be nice.
    Welcome back!
     
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  11. Darkzillicon
    Joined: Jan 2023
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    Darkzillicon Senior Member

    86 F
     
  12. DogCavalry
    Joined: Sep 2019
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    Location: Vancouver bc

    DogCavalry Senior Member

    I went with forward sloping. The huge loss of utility for a minor reduction in wind resistance in a part of the speed envelope I'll rarely go seemed a bad bargain.
     
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  13. Darkzillicon
    Joined: Jan 2023
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    Darkzillicon Senior Member

    I’m leaning that direction with similar logic, however I’m also studying books of classic gar-wood and Chris craft boats. They did a lot of boats with a small aerodynamic cabin, similar to what I envision for my boat.

    also my larger boat i’ve driven into 45 mile an hour winds during a thunderstorm, and I had to remove all of the canvas to be able to see the channel markers at night. I don’t plan on being that captain again but I’ll always have that as plan b.
     
  14. BlueBell
    Joined: May 2017
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    Location: Victoria BC Canada

    BlueBell . . . _ _ _ . . . _ _ _

    DarkZ,

    Why would you go with a cabin in your climate?
    The plan doesn't call for one.
     

  15. Darkzillicon
    Joined: Jan 2023
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    Location: Palm Beach

    Darkzillicon Senior Member

    • I like to go boating at 3pm. In my climate it rains every day at 3pm like clockwork. I want a cabin.
    • It will be built very light, and I've done the weight study for it.
    • If you look at the pdf plans you can equip the boat with a cabin if you so choose per the picture.
    • reserve buoyancy should be 5000 pounds. very conservatively.
     
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