This is the first of a series of tutorials about a catamaran I built back in the 90s. Building a boat, something big enough to live on and sail off over the horizon is a dream I had for years. My original idea was to build a monohull, in fact I bought plans for a little 21 footer.
That i was going to weld up and sail around the world in. The plan got postponed for a number of years and in that time I come across a couple of books that changed my ideas. It was back in the early 90’s First book was the Gougeon Brothers on boat building, all about building with epoxy and wood.
And the other book was the cruising multihull by chris white. The two of them together made sense Building a multihull, that didn’t rely on tonnes of lead to keep itself upright and building with wood, epoxy and fibreglass, all made sense to me. I found plans I liked from a local multihull designer, Tony Grainger. I then started preparing the place to build it,.
In the bush on my parents property out the back of noosa heads. Queensland, Australia. The original shed was only big enough to build the 21ft boat that I originally planned to build. So I lengthened it with the idea of building the boat in 3 sections.
2 hulls separately and then the centre section. Which I ended up doing. Building of the hull starts with a strong back. It’s a ladder like construction that I concreted into the ground. I cut out temporary frames in chipboard. to make the cross sectional shapes of the hull.
Using full size contours on mylar sheet that I laid down on the wood and traced out with a dressmakers wheel. Each temporary frame is set up on the strong back. and lined up. It’s worth spending a little extra time to get everything spot on at this stage Getting it all lined up perfect.
And the contours cut out perfect. made for an absolutely fair hull. It saves you a lot of time down the track. The construction was strip plank western red cedar. Basically a wood cored fibreglass boat. My reasons for building it this way.
Were that its a simple system for a one off boat You don’t need to build a mould before you can make it. produces a very fair hull. It’s strong, its light. The cedar strips were 14mm thick and for the majority of the boat 90mm wide.
How to build a boat in 1 month
This tutorial is an overview of how to build a small boat. Over a period of a month, in our spare time my son and myself built a 3 metre plywood boat in a one car garage. For little money and some basic tools, we ended up with a fast stable craft that you could walk to the water.
And in queensland australia, you don’t need a license and the boat doesn’t need to be registered. So the boat started life as a sketch, with some dimensions on it. I used a free CAD program called Delftship, to create the boat in 3D.
The program generates a lines plan which is a layout of all the pieces that make up the hull. with dimensions on it. The material list for the boat’s not very big a few sheets of plywood and some pine framing from the local hardware store (Bunnings).
The plywood’s scarfed together to make up the full length of the boat. I then transferred with pencil, the dimensions from the lines plans onto the plywood. Then we cutout all the pieces with the jigsaw. Once the pieces are cut, it’s really cool to see.
How quickly the boat takes shape. once you start bringing the pieces together. The shape of the hull on this is a little unusual. It was an experiment. Which, in the end didn’t really work out. But that’s OK.
It was easy to cut and modify later on. (next tutorial) The pieces that make up the shell of the hull are brought together around the frame and the transom. The flat plate at the back of the boat. The pieces are all screwed together temporarily with tangs of metal.
Blocks of wood, screws, you can even use cable ties. It doesn’t really mater putting holes in the wood because you’ll fill after with epoxy. The whole boat is glued together and finally coated with epoxy resin. It’s all done with epoxy.
Epoxy resin with a filler (cabosil) to thicken it, is used to stitch glue the wood together, in the beginning. It’s almost like spot welding in metal. Once the glue dries you can take out the screws. Once the boat’s been spot glued together and all the screws have been taken out.