One Sheet Plywood Boat

I have always wanted to build myself a boat. This was maybe not the one I had in mind. But I have to start somewhere I guess.:-)

It's a pretty simple and quick build. The boat is made from just one sheet of cheap construction plywood.

I made a little video of the build if you want to see the process in moving pictures too.

Video of the one sheet plywood boat

Tools used

• circular saw
• jig saw (optional)
• drill (with a drill and countersink bit)
• impact screw driver
• long ruler/straight edge
• Sanding block
• Pen and tape meassure

Other things used

• Silicone (wetroom FA180)
• Screws (drywall screws)
• A paddle
• Linseed oil for protection of the wood

Step 1: Meassuring and Marking

Here is my layout of the sheet.

I made my boat a bit shorther than it needed to be. I cut off about 40 cm (the top of the sheet in the second picture). Why? Several reasons. :-)

• I wanted it to fit inside our car
• I wanted it to be easy to carry
• I was unsure if I needed to reinforce any part, so I needed to save some plywood for later.

Step 2: Cutting the Parts

I used a circular saw to cut the parts.

The boat will be constructed out of four parts in total. A bottom and three sides.

Step 3: Bending the Boat

I have seen other design where the bottom is cut to make a angle in the front of the boat. I wanted to have a bent bottom instead.

As you see in the pictures (hopefully) this is when the sides gets it final length and angle (in the for). I hold one site up to the bottom and trace the curve. the I use that side as a template to trace on the other piece to make them the same size. If you cannot hold the pieces by hand, use some clamps.

The thickness of this plywood is 1,2 cm. I set the depth on my circular saw to 5 mm and cut lines where I wanted to bend the plywood.

I will later put silicone in the cut-lines so the structure will be rigid.

When I can see that the plywood bottom bends right, I hand sand the parts before putting it all together.

Step 4: Parts

Here is the parts. You can also se the lines in the front of the bottom that makes the plywood being able to bend.

Step 5: The Assembly

I put silicone around the bottom and use a small nail gun, just for speeding the process up. I use as few nails as I can. Then I put the left side on, the back and then the right side.

I put a few screws in for support.

Remember to pre-drill and counter sink all the screw holes.

I actually put silicone in each screw hole and on top of every screw too.

Step 6: The Bottom

When the sides is mounted, and bend the front to the sides and put in screws. Then I add more screws from the bottom side.

Remeber to seal everything with silicone.

Step 7: The Result

There is some more pictures of the boat "Förlisia" and action shots is found in the video here. :-)

This was a really fun build and a perfect summer project. Took a couple of hours to make. I had no plans to go on, so I made things up as I went along. So I have some suggestions for improvement.

Improvements

If possibe - use the entire length of the ply sheet.

If you are not as heavy as me, you can have shorter sides (making the bottom wider and the boat more stable in the water). I had 30 cm height on the sides. If you go with 25 cm instead, you get 70 cm wide bottom instead.

I would place some runners underneath the bottom, making the boat go more straight in the water.

I would make something to sit on, so its more comfortable.

Thank you for reading this instructable! Please let me know if you have any questions or let me know what you think. It's much appreciated! You can also look at my other projects here on instructable or check out my YouTube channel.

A vote for the boat?

I entered the Water Contest, so if you like this project please consider a vote for this little boat! :-) It would be much appreciated! Thanks again!

Comments

[Glumgad]

How did you make plywood waterproof or water resistant?

[dekeros]

Hello and thank you for your question! I put silicone on all "end grain" and screw holes. I also treated the wood with linseed oil after the silicone was cured. I built the "boat" last summer, had it in the water a couple of times and stored outside during the winter, just to see/test how it held up. This summer, I see no wear or tear. But before putting it in the water I put on a another coat of oil a week or so before. I'm thinking on putting clear lacquer (for boats) in the near future to make this last longer. Thanks again - a very relevant question - glad you asked! :-)

[charlessenf-gm]

" I'm thinking on putting clear lacquer"

Fiberglass resin would be better. And Dupont 5200 would serve you well at the joints before fiberglass resin.

[dollywild]

in the US if you look for something called Spar varnish, you can use that, as well. if you use linseed oil, it would be wise to put on a fresh coat every season.

[dekeros]

Hey there! Thanks - yes, that seems to be the same we use here, but I was unable to find the right translated word (spar varnish). Now I know! :-) I have not decided yet if I want to use something clear or paint it.
Thank you for your input - much appreciated! :-)

[laparsons]

I built almost the same boat, used full length of Plywood. I used 2x sheets of plywood.

[AbN]

This is a wonderful design. Yes adding a seat would make the sides more rigid and strong.
Have you considered to maybe add a sail so you don't have to paddle so much?
Great job!

[dekeros]

hey! thank you very much for that! :-) when I built it I wasn't really sure how it would come out. But a seat and sail would be something to include in my next build. The boat needs to be a bit larger then. :-) Thanks again - and have a great day!

[a7xrebelrocker]

Hi, I have a question. What is the measurement from the front of the boat to here, where it will start bending? Thank you in advance.

[idb2022]

I have same question. Looking at a similar design I think this is about 50cm from edge of sheet?

[Luke12]

Awesome design! What thickness of plywood did you use?
My family has been sailing/boating all our lives. I am planning to make one into a small "play sailboat" for my 2 year old grandson for the back yard.

[epassos]

I got to these measurements from your boat.

[dekeros]

Hello! Sorry for my late reply! That seems about right. I have a picture in the fourth picture in the first step and you have the same meassurements there I think. But - consider making yours a tad larger for stability. I wanted mine to fit in the back of my car but it would be more useful if it was larger. Good luck!! Cheers!

[epassos]

Please thank you very much for your reply.

[epassos]

Hello, I really liked your project, I would like to make a boat, but for me it was not very clear the measurements, what is the length, width and height? I would be very grateful if you can tell me these measures. thank you.

[milesnorth]

Sweet!

[dekeros]

Thanks!! :-)

[tayhey]

Hello, we are trying this now, but are a bit puzzled about the dimensions shown on the sheet that you marked out. It looks like the bottom is shorter than the sides, whereas, it would need to be slightly longer to enable it to curve up around the sides.Can you clairfy? Thanks.

[dekeros]

Hey there! Thank you for checking out the instructable and your question. You seem to have found an error I made. Sorry about that! I have updated with a new picture with more accurate dimension. When I made it, I had no plan and just freehanded it. The sides is a tad shorter than the bottom. I will add that to the instructable text. Please note that I also made the sheet shorter (a full sized sheet is 240 cm long). But If you try to make this, use the entire length for a larger vessel (more stability). Hope this helps - and sorry again! Thank you for pointing this out to me and good luck! :-)

[tayhey]

thks