I am going to start by saying that because of the shear size and nature of this project it will have to be a two-part Instructable. However, I will end the first part of our quest in building a sailboat with a fully functional rowboat. In Part 2, I will finish the work needed to turn our rowboat into a wind powered sailing vessel. Come join in the adventure!
For starters you will want to either design or buy plans for the boat you want to build. My build will be the Whisstock 55. You can start this project by locating your nearest makerspace or local fabricator otherwise all CNC steps you will have to do by hand. I used a CNC on any curved components 8 feet or shorter. Anything longer than 8 feet I did by hand. If you bought plans for your boat and they came with digital files you are one step ahead. I used Autocad to recreate any part the CNC would cut. Instructions on how to CNC can be found elsewhere. I will focus on piecing together a boat. You might be thinking right now this is already too daunting. With a little patience and a lot of ambition you can make your dream boat. I want to note that I have never built a sailboat before this nor have I even been sailing. We hope this Instructable highlights how possible this is.
Step 1: CNC and Laminate Your Frames
Using your CAD files, per your design or per plans, you are now ready to cut your frames. Because of the curvilinear nature of a boat your frames should have a bevel otherwise your boat would be a box. This is easily done either as one monolithic timber on the CNC or by laminating up a few sheets of cut plywood. Then as you sandwhich them together they should slightly expand in the direction your boats gets wider. You will then bevel the edges after they are laminated. We will be using marine grade plywood and West Systems Epoxy. After all your frames are cut epoxy them together and clamp them tight.
Step 2: Build Your Jig
Your Jig is the frame in which you will build your hull around. This may be the most important step of all. Your jig will have to be true, square and rigid. Don't rush through this step. This, in essence, is your foundation for the build. Once your jig is complete start fitting your frames to the jig making sure they are securely in place and all their notches are clean and ready to receive the other parts.
Step 3: Begin Work on the Stem and Keel
Again, we laminated plywood cut on the CNC where we could and when we couldn't we did this by hand. The whole boat is either marine plywood or mahogany. Construct your Stem and Keel per your design and secure them to the frame. Very little fasteners are used in this whole build. Largely they are used just to secure parts as we wait for the epoxy to cure. No two boats are the same. Even if you are to buy plans your craft will begin to deviate from the plans and you will be designing as you go. This is the beauty of the build. It is your fingerprint on the project.
Step 4: Lapstrakes
This part can be intimidating. But you have come so far! For me the easiest way to figure out how to do this was by taking measurements from the face of my keel to the end of my frames. Then I divided the lengths by the number of lapstrakes I wanted. The total length of my boat is about 16 feet so I had to scarf the sheets of plywood together.
I made a scarfing jig. This allowed me to create beveled edges on sheets of plywood. The plywood was ripped down to the maximum size of my largest lapstrake from the previous measurements. Then i glued two 8 foot sheets of ply together to get my 16 foot lengths.
From there I began attaching my lapstrakes to my frames. I just want to note that sometimes your lapstrakes will come out in the funniest looking shapes per your measurements. As you bend them around your frames they will fit. So don't be alarmed. Countersink holes that you can plug later. Lather on epoxy and mount your lapstrakes. Important: Do only one lapstrake, per side, at a time then remeasure. This will allow you to make up any differences you need to get to the shear which is the end of your frames.
Step 5: Lapstrakes Continued...
Continue working your way down your frames adding a lapstrake to each side then measuring the distance to the shear and dividing by the number of lapstrakes remaining. After each lapstrake you will need to hand plane or belt sand a bevel on the edges so the next lapstrake will have a surface to sit on and a nice bed of epoxy to secure to. You will notice our lapstrakes have a color to them. This is a ebonizer I created and was trying out. I eventually sanded this off and applied a new one when the hull was complete. Then I epoxied the entire boat.
Step 6: Flip and Epoxy
Now is time to part with your jig. You will flip your boat and remove the jig. You will need to create a support to hold your boat upright while you work on the inside. Epoxy the entire inside.
Step 7: Deck Structure
Lay out the structure for the deck per your design. Epoxy this to your frames. When your structure is in place you can lay your deck down. I roughed out my deck with a jig saw and came back with a router to edge it flush to the shear. When the deck was secure I trimmed off the edges flush.
Step 8: Benches, Centercase and Centerboard
Frame out the Centercase that will house your Centerboard if you have one per your design. Frame the structure for your benches and finally secure your benches and thwart. Create your centerboard. Mine is laminated ply with lead shot mixed with epoxy and poured in holes inside the Centerboard for weight. I then finished this in epoxy and graphite. The graphite helps create a low-friction coating with increased scuff resistance.
Step 9: Finish and Create Oars
Finish your boat as you see fit and per your design. Some people paint them. Others like the look of the wood. This boat was epoxied and varnished. To finish part 1 and get your boat on the water you will need oars. You can create these from a template and then plane to profile.
Step 10: Get Ready for Part 2
Congrats! You did it. Hope to see you in Part 2 as soon as we finish but this will keep you busy for awhile. We will begin Part 2 making our Mast. Until then... Cheers!