The BO-AT Single Sheet Plywood Boat

My son and I built this simple one sheet plywood boat following the plans and sage advice provided in the following link  http://blog.makezine.com/archive/2011/07/the-blue-crab-one-sheet-plywood-boat-tiny-yellow-house.html.  We saw this in a recent eNews from Make Magazine.  This is Not our design but I wanted to share what we learned.  This was a simple and fun project to build and cost us a grand total of $59 dollars and about 6 hours (not counting Beer and Juice Boxes).

We went to our local hardware store and purchased the following supplies:

1 Sheet of 4x8 15/32 Plywood Sheet
Gorilla Glue
Silicone Sealant
Latex Paint
Screws
Paracord
Sand Paper

Depending on the size of your workshop and the tools available to you, you may decide to have the store cut the 4x8 sheet of plywood for you (as we did) - just make sure they cut it right (as we did not) - it will save you trimming and increase you freeboard later on.

Tools Used:

Jig Saw
Caulk Gun
Screw Gun
Measure
Clamps
Drill
Paint Brush

In the video link for the first page you can see how to cut out the various parts for the boat.  You will need to make the following cuts:

1 - 24 inch by 96 inch sheet for bottom, bow and stern - this part we further cut into three parts:

1 - 18 inch by 24 inch part for the bow
1 - 12 inch by 24 inch part for the stern
1 - 24 inch by 66 inch part for the bottom

2 - 12 inch by 96 inch sheets for the sides - will be further cut to match the angle of the bow while assembling

3 - 1 inch by 2 inch by 8ft boards for supports - cut to size

1 - 1 inch by 3 inch by 8ft board for trim on bow and stern

2 - 1 inch by 2 inch by 8ft boards for deck - cut into 24 inch planks and then threaded with 550 paracord for deck

Once all the parts have been cut to size, the assemble quite quickly.  In the video they recommend that you glue and use brads to hold the boat together.  I used screws instead but think the brads would work a bit better as you would not need to pre-drill the holes as I did to keep the screws from splitting the wood.  I only used the screws because I was too lazy to drag out my air compressor!

I began by attaching one side to the bottom first.  After this I attached the stern and here is the order I followed (not sure it matters but this was the way I did it):

1. Left side to Bottom
2. Stern to bottom and Left side
3. Right side to bottom and stern
4. Bow to Bottom and both sides
5. I then used trim (1 x 2) at all the joints to give me something to screw into

For each part attached, I used the Gorilla Glue and then clamped and screwed together.  Having a second set of hands is great for helping to flip the boat over and back several times as you build it.  It also comes in very handy (pun intended) to fetch and open the Beer.

The last items I attached were the 1x3 trim parts on top of the box and stern - these were added as much for looks as for an easy hand hold for carrying.

I also made a change to the seat design that he had used on his boat.  Because my son is about 100 pounds lighter than I, our ballast in the boat needs to be arranged in a much different manner.  He can sit much farther back than I without taking on any water in the stern.  For this reason I used the 1 x 2 boards strung together and laid in the base of the boat on the 1 x 2 rails.  We can slide this front to back without any issue.  I also was not comfortable with how high his seat sat and feared it would create a too-high center of gravity in an already wobbly boat.

Once assembled, the next step is to sand the boat to a nice smooth finish.  We tried to round out all the edges somewhat to keep from scraping any body parts while on the water.

After we had a nicely sanded boat, we went a bit wild with the Silicone Sealant.  This is not a bad thing as this is basically what keeps the water outside your boat and you dry.  I gave the Silicone a good 24 hours to dry before I applied any paint.

After the Silicone has dried, you are ready to paint the boat.  I used a Valspar Latex Enamel paint.  We applied three coats to the outside surfaces of the boat (green in pictures) and two coats to the inside surfaces (tan in pictures).  between each coat I waited the recommended time for drying and sanded lightly.

Now that I have had it in the water, I will put another coat on at the water level for some added protection.

One thing to note is that paint does not adhere well to Silicone so where ever your sealant is, your paint will not look very good.  This is more cosmetic than a problem. 

Pick a nice and sunny day on a not so leach infested lake (this is Gropps Lake in NJ) and head out.

As you can see from the pictures, the boat does okay.  It is by no means a speed boat or a stable boat but it is fun and it can displace quite a bit of water (held about 400 pounds and still had just over an inch of freeboard).

This is a much better boat for someone my son's size and handled quite well.  When I got in and my cousin, things went a bit wobbly but were still enjoyable.  When we both got in we were having flash backs of the Titanic!

My next test will include a very small electric trolling motor for some fun.

This was just a fun project to do and I thank Make Magazine and Derek “Deek” Diedricksen for posting it.

I should title this part Load Test because I never got to try the motor - bad battery.

I will update after I get a new one.  Also need to trim the top board back by the stern to fit the motor bracket.  I had to remove the board to fit the motor.