This Instructable documents how I built a small sailing boat out of a mussel float, and advice on how to build your own! This project took me about four days working on and off and in a rush, so there were many corners cut and compromises made. If you are an advanced DIY person/ boat builder you can probably make a project like this look a lot nicer as well as use higher quality materials (although you might as well build an actual boat in that case!).

This project came from an idea I had that combined a boat with a chair. A boat small enough to be turned on its end and sat in, a bit like the fancy designer ball chairs. This would allow it to be stored in your living room when you weren't using it. Obviously, there are a lot of issues with this idea such as transportation, what to do with the masts and other bits, as well as drying it off before taking it indoors again.

Whilst this boat does transform into "chair mode" well, using it as a chair is not only very uncomfortable, it is also impractical and I don't really recommend building chair mode as a feature into your design.

Tools and Materials:

The basic tools used for this build are mostly home power tools. For the serious connoisseur I would advise the use of some extra more specialised (but sadly less available) equipment.

Essential tools are:

Drill (cordless or corded, matter of availability)

Assorted drill bits (wood screw tap and clearance size, countersink and large forstners or flat bits)

Jigsaw (You'll be cutting stuff)

Hammer (Bishy Bashy!)

Hand saw

Drawing Instruments (you could probably build this without marking anything out, but it will be infinitely easier to use a pencil and ruler)

Dust Mask (I might say this is optional, but respiratory problems are optional too. The choice is yours)

For ease of building, recommended extra tools are:

Bandsaw (allows nicer cuts and right angles etc)

Power File (probably my all-time- favourite tool. Great for smoothing edges and shaping stuff)

Table Saw (cutting planks was never so much fun!)

Chisel (You will probably use it at least once, best to have it handy)

Blowtorch (always useful)

Clamps (they will make everything easier)

Eyelet Press (cheap, hammer-operated ones work fine. If you're careful you don't even need one and can substitute it with a ball pein hammer... If you're careful.)

Sewing Machine (Real men don't sew. That's why I used a sewing machine to hem the edges of my sail.)

Materials you will need:

Mussel Float (obviously)

Wood (pallets are a handy source of cheap, rubbish wood. Your pride will dictate the quality of the wood you source)

Plywood (as with the wood, how good the plywood is will depend on your budget and/or scrounging tolerance)

Wooden Dowel (pick a good size for the mast and rudder shaft of a tiny boat like this)

Screws (if you're smart you will choose something non-ferrous so as not to rust in the water. If you're me, you use cheap steel ones)

Nails (see screws)

Boat Bits (I had these lying around. Try nautical jumble sales, car boot sales etc if you need them, or improvise)

Plastic Pipe (I found a 20ft length of polypropylene pipe on the beach, and PVC conduit pipe is used as well)

Jubilee Clips

Curtain Ring (Trust me, this has an actual use later on)

Rope (If you've already found a mussel float, PVC pipe and lots of wood on the beach, I will assume that rope is not far away. Otherwise, the rules that apply to wood quality also apply to rope)

Gorilla Glue (Everyone should own a tub of this. If you don't already own some, go and buy some now.)

Eyelets, Eye Bolts (for rope control and sails)

Sailcloth (or an old tent, or bedsheets, or paper napkins taped together. The braver you are, the lower quality your sails can be. I am a coward, so I use actual sailcloth.)

String, Cord, Thread. (Assorted stringy things for sewing stuff.)

Step 1: Find a Float

Mussel floats aren't the most common of things. If you live by the sea, you may be lucky and find one washed up on the beach as I did.

However, chances are that won't be the case, so you will need to improvise. The mussel float is made of rotationally cast polypropylene, so it is thick and damage resistant, suited to life at sea.

You could probably use any similar vessel, like a fiberglass bathtub (wear breathing apparatus), a cast iron bathtub (wear diving apparatus) or some kind of septic tank or cold water tank. I won't deny that I would love someone to try out this instructable on a bathtub.

Important when choosing your hull is the amount of freeboard you will get when you are in the water. Freeboard is the distance from the water level to the upper edge of the boat (the point at which the water will start coming in). As you can imagine, a very small freeboard will likely sink your boat if someone throws a stone in the water near it, as any waves will just come over the side.

So it might be wise to test your hull in a handy body of shallow water prior to deciding to use it for a project like this.

Before starting this project, I tested my hull in a duck pond, and ensured that I had about 11 inches (about 28cm) of freeboard before I was satisfied and went ahead.

I cut my float in half with a jigsaw in order to get my hull shape. I made sure that the rib on the float was running under the boat in order to give it a keel-like effect to help attach bits to later on in the build.

Step 2: Plan Your Boat

This bit is not vital, but it is very, very handy.

Proper planning of a project can help forsee problems that might arise later on in the build, as well as work out logistical issues to do with complex things, like "Where do all these bits of boat go in order to make a boat?".

It's useful to do some scale drawings, perhaps make a model or two to get a feel for what can happen, and what you want to happen during the build.

Since my design was for a boat-chair, the requirements were that it worked as a boat, but also stood up on its end to be sat in vertically. This meant that there couldn't be any sort of centerboard or keel as it would interfere with the chair mode of the boat. I considered a detachable keel or daggerboard but discarded those ideas as they would add extra fuss into my short-timescale build.

You might want to also look into various sail plans and think about what one is best for your boat. This may take some time, as wading through nautical jargon can be confusing if you don't know the words for things, but after a while you will find out some useful information to help you design your own boat.

Step 3: Get Building!

Since there were four days to build this in, I was working quickly. This meant a lot of cheap-outs and recycled pine pallets.

One of the first steps was to add the bit that holds the base of the mainmast, called the Tabernacle. This, I made out of some beach-salvaged polyprop pipe which was the same plastic as the float. This, I decided, would allow me to weld them together with a blowtorch.

I cut the pipe so that it fit more or less into the boat where I wanted it, and so that the gap was small between the pipe and the surface.

I used a blowtorch to soften and melt the surface of both the end of the pipe and the receiving floor of the boat, then pressed them firmly together to make a (hopefully) tight permanent bond.

Step 4: Fitting Wooden Parts

I laid the hull out on a sheet of plywood and traced with a pencil around the outline to get a vague idea of the profile of the bow and stern. I cut it out with the jigsaw, and used both the inside and outside bits of the cut sheet for the bow and stern decking respectively.

When screwed on, the plastic deforms and covers up any minor imperfections in the shape.

Screws were tapped with a 1mm drill, and countersunk so as to be neat.

The stern 'gallery' was built down from the deck using the bandsaw and powerfile to shape the planks to the hull. All were tapped, countersunk and screwed into place.

Step 5: Keel and Rudder

The keel was cut from an old tabletop, using a template created again by drawing round the outline of the hull. The rudder was part of the keel, and then cut out and shaped. It had a section removed in order to fit with the rudder pivot, a piece of dowel running inside a wire conduit pipe sealed to the hull so as not to let water in.

The keel also had an aquadynamic foot added for stability and strength when in chair mode. This foot will probably cause some turbilence and drag behind it, but that's not too big of an issue.

Be careful with wood that you find, especially if it's not very good. This tabletop was made of glued planks which broke apart when cut. I had to reattach them and wasted some time doing so.

You could add a daggerboard/centerboard to your boat for added stability in the water. The board generates lift as the boat moves forward and acts to counter the tipping force caused by the sail.

Step 6: Mast and Bowsprit

The main mast was made out of two broom handles joined end-to-end with a sketchy wood join using a pin to provide tension. My attitude towards this joint in the end was "enough glue will make it work". The mainmast went through a hole in the front deck and into a piece of wood in the tabernacle to hold it in place. It is to be secured by mainstays prior to sailing.

I chose to add a bowsprit because in my mind boats have bowsprits. It also opens up the possibility of having a jib (front and triangular) sail at a later date. The bowsprit was a slightly smaller broom handle, with thin peg inserted perpendicular through the inboard end to stop it sliding out of its mounts.

It was held in place in two cradles by a jubilee clip, which forces it down and stops it moving. This means that it can be quickly removed for transition to uncomfortable chair mode.

Step 7: Seat and Interior Deck

The seat was done using the same method as the bow deck, drawing round the hull as a template, and cutting with a jigsaw. It was screwed into the rim of the deck in a manner similar to the front one, although the edge had to be chamfered slightly to fit with the curve of the inner of the hull.

I added a tiller extension, as there was no way that anyone sat in the front of the boat would be able to reach round to use the tiny tiller. I also put a clip to hold the extension when it wasn't being used.

For the floor, I cut four ribs to fit inside the molded shape of the buoy. These were screwed in from the outside, and the screws were sealed by means of silicone applied to them when they were being screwed in. The slats for the floor were cut from scrap wood and shaped such that they would approximately follow the contour of the hull, and look boat-like. I nailed them down with some old copper nails that I found in a box of boat fittings.

Step 8: Rigging

The rigging was mostly made from a 30 foot (10 meter) length of blue plastic rope I came across on the beach, although the mainsheet (the rope to adjust the main sail) was a length of nautical rope found in a box of fittings.

I put a large eye bolt at the stern (back) of the boat to take the mainsheet, as well as several smaller eyelets through which to run the mainsheet to the bow (front) of the boat where the captain could operate it.

The mainmast had two perpendicular horizontal holes drilled through the top of it, one for the stay from the bowsprit, and one for the mainstay which is tied to either side of the hull at the front.

The gaff boom was made from some thin dowel with a curtain ring at one end to slide up and down the main mast by means of a pulley mounted at the top When mounting the curtain ring I cut a channel at the end of the boom, and glued and screwed the ring in, with the ring's grain travelling in the direction i thought best for strength. The pulley is tied off at a cleat at the base of the main mast.

All that is left of a build like this is the sail itself, although I ran out of time, and will have to add the sail at a later date. I plan on also adding a jib (triangular front sail) if the weight of the mainsail is not too much for the boat's stability.

When rigging your craft, it's useful to read about the various types of sail plans and what sailing with them entails. I chose gaff to get a large-ish sail area but also a short mast, so there is enough sail for propulsion but also not a large amount of leverage acting to tip the boat over.

Step 9: Sails

Since you are making a sailing boat, it would be helpful if you actually had a sail. Otherwise it would just be a boat, and at about four feet long, barely even that.

So once more into the boat-bits-box went I to find a bolt of red sailcloth. I am aware that this is a very unlikely thing to have hanging around, so I would recommend browsing Gumtree* or Freecycle* or any such website or local charity shop to find some lightweight windproof fabric. Ripstop nylon is a good catch, if you find a second hand or broken tent you should be able to repurpose some of the material from that.

Decide what size you want your sail to be. This is determined by the height of the mast, and the length of the gaff boom. I opted out of having a lower boom for space saving reasons. Cut your sail to the shape and size you want plus about an inch, or two and a bit centimeters on every edge if possible for hemming. My material was not wide enough to allow extra on all sides, so I chose to hem all the sides except the side by the mast, as it wouldn't be flapping around in the wind and risk tearing. If you don't care too much about this, you can skip it, or preferably put duct tape over the edges to stop them from fraying.

If you choose to hem with a sewing machine, be careful that your material isn't too thick for your machine to handle. The stuff I used was a close call, but did work in the end. Remember to reverse the stitches at the ends (I had to redo one side because I forgot this step) to stop the thread coming out. Consider using a leather needle if you have nothing better to do with your time.

You can then punch some holes in your cloth for your eyelets using the eyelet punch (or red hot poker, bradawl...you get the picture).

For those that add eyelets and don't just skip the eyelets (you can!), put the eyelets halves through the hole and punch them together with the punch and hammer. This grips the cloth, and makes a nice fray-free hole in your sail.

When you have punched all the holes, you can tie the sail onto the mast and gaff boom using some knot and threading the cord through the eyelets and around the mast/boom.

*Other getting-rid-of-unwanted-stuff websites are available.

Step 10: Done!

Once you've put a sail on your craft, you can take to the water and test it out. Be sure to post in the comments about how your voyage goes if you do try out this instructable. I'd be really interested to hear how it goes if you do (I'm hoping for someone to do a bathtub).

I'll advise you to wear a life-jacket, though, and don't go out in a boat like this without telling anyone where you are going, especially in an offshore wind.

Following my initial test, I decided to add a jib sail, as the boat kept nosing into the wind. I'll test it again, and update with a video of said test.

If you've liked this instructable and feel that you might be interested in other projects that I am working on, you can find me on twitter at @CHAPomeroy.