Thursday 16 August 2012

How to build the cardboat.


For anyone wanting to build the cardboard boat, here is the design used in 2010 and again this year.
The boat was designed to take two people, to be reasonably stable and manoeverable for a circular course,  and to float without any waterproofing.
It is based on the largest sheet of doublewall corrugated cardboard that I could buy from a box manufacturer. I had to fold it roughly 3 times in order to fit it into my car ( a mini). Extra folds are not ideal but you can get away with it.
You can modify the dimensions. Making the boat narrower than 62 cm will make it less stable but if you want to race in a straight line it might be worth the risk.  If there is only to be one occupant then it could be shallower on the sides as well as narrower. Be aware though that, by changing the dimensions, it is very easy to end up with bow and stern that point downwards so the boat won't sit flat on dry land. This may not be a problem if the boat is boarded when it is sitting on the water.
Plan view looking down on the inside of the hull.
Use a metal ruler or similar straight edge tool to press down on the fold lines while bending the cardboard, taking care not to puncture the cardboard in the process.

The cockpit could be improved but is adequate to fit inside the hull as specified above. Its purpose is to keep the shape of the boat.In particular, taping the cockpit to the bow and stern stops them being pushed inwards and upwards by the pressure of the water; taping along the sides of the boat prevents the boat from lozenging and the sides from being pushed inwards too much.

     
Plan view of the inside of the cockpit.

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8 comments:

  1. Raivyn18 May 2016 at 23:53

    Hi quick question about the cockpit. Was it cut to fit inside the hull? I didn't understand the crisscross pattern.

    Love your design!

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    Replies
    1. Cardboat Builder19 May 2016 at 01:32

      Thanks for the comment and question. The crisscross patterned areas were discarded. Yes. It was cut to fit inside the hull. The cockpit is actually crucial to the rigidity of the boat. The cockpit base lies flat on the hull but along the sides it creates a box which prevents the boat from lozenging.
      As long as you don't puncture the carboard skin, the boat will survive a long time in the water.

      Delete
  2. Unknown8 September 2018 at 10:54

    Do you have a better photo of the inside of the cockpit? Or a list of the measurements?

    ReplyDelete
  3. Anonymous27 July 2019 at 03:32

    The cockpit is the same as the hull except you trim off the sectors not required.

    ReplyDelete
  4. xumuc che30 March 2021 at 20:36

    I did it on paper, now is time to do it on cardboard, thanks from Argentina
    I will see how to make it waterproof

    ReplyDelete
  5. Harold28 November 2021 at 15:43

    Can I get a copy of the dimensions with readable dimensions. I have a 13 year old interested in building something useful. Thought this would be a good project for us. Harold gr8ride4u@gmail.com

    ReplyDelete
  6. Unknown30 November 2021 at 03:15

    Hi. I'm not sure where the original images are. I've downloaded the images from this site and blown them up x2. I think the dimensions are readable. I'll email those enlargements to you. The design is waterproof as long as the cardboard is not punctured. Care is required when making the creases for the folds. Dent the surface with a straight edge. Don't score it with a knife. If water gets into the corrugations, the cardboard structure will weaken. To get such large sheets of cardboard I went to a supplier of boxes and picked up the sheets that they use for making boxes.

    ReplyDelete
  7. Unknown12 December 2023 at 09:52

    Hi, how much did it cost?

    ReplyDelete