PlyWood Regatta. SB High School Help plz?

Discussion in 'Boat Design' started by Alex J. Cejas, Apr 4, 2006.

  1. Alex J. Cejas
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    Alex J. Cejas New Member

    Im from South Broward high school, Wer having a Plywood Regatta. We have members, and we have this supplies:

    ~ 3 Sheets of 4' x 8 1/14'' Luan Plywood
    ~ 2 pieces of 2' x 2' x 8' Wood
    ~ 4 Pieces of 1'' x 2'' x 10' Wood
    ~ 2 Spools of wire ( total 100' )
    ~ 12 cartiges of 3M 5200-fast cure caulk( i think its the glue )
    ~ 2 Life jackets
    ~ Paint.

    We Can only use the wire and glue. And some Supplies like Drills, Jigsaws, caulking Guns, and 1 electric cord.

    We have to make a boat and pain it from 8 AM to Sundown. We have a pretty good Team. 8 ppl. and The event will take place this last week of April.
    After we make the boat the next day we Race them.
    It would beawsome if anyone can give me any ideas how boats work made of ply wood. We r gonna have 2 ppl in the boat, both prettylight and strong. But How do we make the boat go a little faster?
    What desing would work best, ithink canoe shape is good but i dont know if its fast =\

    Alex Cejas.
    Help plz
  2. Alex J. Cejas
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    Alex J. Cejas New Member

    Ill bump the thread whilei do Biology homework =\
  3. Alex J. Cejas
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    Alex J. Cejas New Member

  4. Alex J. Cejas
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    Alex J. Cejas New Member

    Hmm Any one there ?
  5. lewisboats
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    lewisboats Obsessed Member

    It normally takes a few hours to get some responses.

    Do a simple square sided, flat bottomed canoe shape, 19.5 ft long with a beam of 28" and sides 10" high. Use butt blocks to connect the pieces, glued and wired together. Use the 1x2s as chine logs to attach the bottom to the sides. Use strips of ply 2" wide to laminate up some support for the sheer edge, stitch it all together. Use one 2x2 for paddle handles with 18" blades, use the other for cross braces for the boat.

    The long waterline length coupled with the narrow beam will make for an easily driven hull, while the flat bottom will give the most stability. You have about 12 hours to build it...I could probably build this by myself in that amount of time.

    Cut one panel in half widthwise, then cut 2 10" strips lengthwise from the remaining panels. Use the short piece in the middle of each side. Measure up 3" from the ends and spring one of the 1x2s to get a nice give a bit of rocker to the bottom for maneuverablity. Cut a 3" wide strip from your 1/2 sheet of ply and use it for buttblocks to connect your side panels and bottom panels together. When they are glued and wired together, Glue and stitch your chine logs on the bottom outside edge, 2 holes per stitch, put your twists on the outside. Cut 1" strips from where the scrap will come from the ends of the boat, each about 4' long. Cut these into 12" long pieces and glue 2 together. These will be your stem pieces. put one on each end, between the side panels where they come together. Glue and run stitches through all the pieces, twists on the outside. This should give you a 1" wide bow and stern stem. Spread the sides apart so the outside edges are 28" apart and use a piece of 2x2 as a brace across the bottom. Make sure the chine logs are up and lay the bottom onto the sides and mark out the shape. Cut the bottom to fit and sew to the chine logs. Use an angled hole, starting from 3/4" in from the edge of the bottom panel to about the middle of the chine log, one stitch every 3". Be sure to use lots of glue. To beef up the sheer, glue a couple of layers of 2" wide ply along the outside top edge of the sides and put as many pieces of 2x2 across the width of the boat as you can. Use any leftover ply (after making your paddles) to reinforce the bottom where the paddlers will sit or step into the boat. Make sure your pieces span from side to side. Leave the stitches in on the ends and bottom but take them out of the sheer before using the boat! Use your remaining glue to fill all the stitch holes and pound the stitch twists into the wood and cover with glue for protection from sharp points.If I have forgotten anything I'm sure you will be able to figure it out.
    Strategy: Use your lightest strongest people as paddlers, with the heavier of the two in the back. If you have people with experience paddling...use them regardless of weight. Keep the paddlers as far apart as comfortable and with the paddles on opposite sides. Have the back person call cadence...Stroke! Stroke! Switch! Switch sides every 10 strokes to keep from getting tired. When turning both paddle on one side and lean into the turn (BUT NOT TOO MUCH!). The back person can use the paddle as a rudder too. Try to get some practice in before any racing.

    Attached is a picture of the finished hull shape. Have fun and let me know if you win.


    PS: as drawn, this boat's waterline is at 400 lbs displacement (3" draft) Boat wt will fall in at about 90 lbs.

    Attached Files:

    1 person likes this.
  6. keysdisease
    Joined: Mar 2006
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    keysdisease Senior Member

    Plywood racer

    Hi Alex,

    I live in Cooper City and am familiar with this event. I've been watching those builds and races for years and it takes me back to making model "can" boats to race across the lakes in Miami when I was growing up.:)

    Steve presents a classic concept for an easily driven boat. But as with many races you can't win if you don't finish. Many of the boats raced in these races capsize or sink before the finish.

    I would suggest a catamaran. Rip the plywood into 16" x 8' sections. Make 2 boxes 16" high and 16" wide and about 10' long. Use the remaining plywood for the but blocks to splice the plywood and paddles. Angle the bow up and square the stern. Use the 2 x 2's in half for 4 crossarms in pairs that will double as seats as you will paddle canoe style with your legs bent under you. Use the 1 x 2's at the sheer (top of hull) to reinforce where the crossarms will attach. If you have enough material make an x across the forward pair of crossarms to the aft pair to keep the boat from "racking.":confused:

    Use any scraps to reinforce the floors where your legs will go and make seats between the pairs of crossarms.

    If anyone on your team has drywall experience let him rip the wood with a razor knife if allowed, it will save lots of time. Keep changing blades as necessary.

    This will net a catamaran about 14' long and 4 ' wide. It will be stable and with 16" high sides should stay pretty dry if it doesn't leak. With the simple square joints it should be pretty easy to build and keep tight. You can split your team into 2, 1 team per hull so you're not tripping over each other. Have your most experienced person :idea: supervise both hull builds so they are as close to same as possible.

    One rower per hull. Most of the time these races are straight line so turning will not be a factor.

    No matter which design you pick practice the build technique with cardboard and wire, it's cheap and will give your team a big edge on the learning curve. You've got plenty of time, so practice your building skills and it will definetely pay off.:)

    Where is the race going to take place?

    Steve in Cooper City
  7. keysdisease
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    keysdisease Senior Member


    Never mind this correction, I just saw the edit button.

  8. sal's Dad
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    sal's Dad Atkin/Bolger fan

    I absolutely agree that practice will help. Use cardboard, or similar, and stitch it together; a week before the competition, make a 1/2 scale model as a team! This way you can work out design details.

    If nobody has paddling experience, borrow a canoe or kayak for a couple hours, to get the feel of it.

    If you are really serious about winning, and willing to spend $50, you can build a full-scale version, and paddle it! Just use "liquid nails" instead of 5200 to save money. Then you can practice paddling. If you do this, you can build it in about an hour during the competition, and paddle as fast as in any "store-bought" boat!

    5200 is VERY sticky stuff, you don't need a lot to stick things together, but make sure you are generous below the waterline, so that you have no gaps! the glue-crew should consider wearing gloves and throw-away clothes.

    I like Steve's design - with a couple comments.

    -- Consider making it 15' or 15'-6" long. This will be slower than Steve's 19', but this way you can overlap the bottom panels about 6"-12", glued together, with only one joint, and no butt-blocks.
    -- The sides will need to be a bit longer to go around the curve; again overlap them rather than using butt-blocks (check this measurement carefully!!)
    -- With rocker (curved bottom) you will probably want to angle the ends of the gunwales (side pieces) to make a nice point. Note that Steve's drawing shows little or no rocker; the boat will be curvier. But not too curvy! don't let the bottom curve more than 3 or 4 inches!
    -- 10" sides sound a bit low for a boat with rocker and novices paddling, consider using 12" or so.

    If you have long pointy pieces left over, use them as decks for the bow and stern. This will keep out a lot of undesirable water, making it more like a kayak. And oh yes, when paddling, sit close together, near the middle - not way out in the ends!

    Most important, have fun!

    Sal's Dad
  9. solrac
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    solrac 100% sudaca

    hey Alex, maybe this can help:

    Attached Files:

  10. keysdisease
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    keysdisease Senior Member


    I just recieved a trade magazine that posted the results of this race. It seems as if the South Broward High vessel "Censored" placed 2nd in the imtermediate division. Another team from South Broward High "Kiwi Magic"also won the "Seafarer Marine award" for the best overall team, team spirit, clean work site and good design that works.

    There was also a scholarship award that went to a Cody Ward from So. Broward who plans to atend U of Miami and study marine Biology.

    Stranahan High was overall winner in "Yo Momma" with a canoe like design.

    From the pictures I can't tell what designs the So Broward teams used, some of these kids may end up here some day!:eek:

    Steve aka "Keysdisease" :)
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    BOATMIK Deeply flawed human being

    The cat shown will float so deeply that there will be excessive wetted area - so it will be slow - and you can't paddle it fast enough to make use of the reduced wavemaking drag of a multihull. Also it may not float a crew of 2 at all. Always do basic calculations

    Lots of these races have been won by 8ft long x 4ft wide scows.

    Just pure reliability. Easy to build and if leaks are minor the scow will always finish.

    Design the bottom with enough curve to keep the bow and stern out of the water.

    People always go for exotic shapes - cats - slim canoes - and then find they don't float upright or can't keep small waves out - or leak and can't be bailed because the hulls are inaccessible or just can't float the crew.
  12. Alex Cejas
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    Alex Cejas New Member

    Don't mean to dig a grave here. I don't remember the other account but I made this thread my freshman year in high school. I'm in my sophmore year of college now!
    I used some info given me here to help our team go on and participate all 4 years. 06, 07, 08, and 09.
    We had the same team all 4 years. 06, 07 and 08 we won numerous prizes for our decoration and designs.
    Our last year, we took home various prices, including beating the college kids in the race.
    Our team was called "Skull Candy."
    Just wanted to bring this up and let people know that you guys helped me out.

    Thanks a bunch.

    My grammar was terrible back then!

    We are still in the front page of the regatta website, the team to the right.
    2 people like this.
  13. hoytedow
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    hoytedow Old Woodbutcher

    This thread resurrection is a good one!
  14. Boat Design Net Moderator
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    Boat Design Net Moderator Moderator

    Yes, thank you very much for revisiting the forum and giving people the follow-up to let everyone know how it worked out. Thanks.

  15. hoytedow
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    hoytedow Old Woodbutcher

    Good luck in college and keep us posted.
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