Be sure to abuse that seam in every way possible! Be cruel and do not hold back. Also, check it for leaks afterwards.
Exactly. Ideally, you'd want to minimize these gaps, but of course, number of stringers is a limiting factor. Obviously, you can make these gaps larger above waterline, because the water won't be exerting pressure there - unless the boat heels, so be sure to account for that too. In other words, try to maximize the number of stringers on the floor, and then gradually increase the gaps between them towards the sheer.
Also, don't forget to make some concave curves in your bulkheads between stringers to accommodate the inward deflection of the fabric. Like here. Notice these slight concave curves between the cut-outs for the stringers. They ensure that the fabric won't press against the bulkheads when deflecting from the water pressure.
If engineered correctly, this lever could also become your king plank once lowered into position, just like in the link Rumars provided.
I feel you! I was student myself when I made my first boat. My budget was also $500, including the rig and the sail. In your case, are you including rig and sail into that budget? If you want a proper rig, the cost of a decent Dacron sail will cost nearly as much as the rest of the boat. If you choose "one-off" Tyvek/polytarp sail, you can make it as cheap as $20. What about the plywood you said you have access to? Did you mean you can get it for free?
With careful planning and access to needed materials, it is possible to fit in that budget, I think. But in any case, a good friend of mine once told me an accurate way of estimating how much a boat will cost to build... Calculate the material costs, tools included. Count every nail, every brush, even the pencils. Assume that tools that will break down and will need replacement. Assume you will make mistakes and ruin materials. Timber often has a knot in the worst possible place, and thus you need a new piece. Epoxy batches get ruined. Varnish bucket tends to end up on the floor, upside down. No matter how careful you are, sh*t happens. Estimate the transportation costs - how many times you're going to drive to the hardware store. Add every little expense you can think of. When you're finally done, and you have your final sum... Multiply it by a factor of 2. AND, if you're very lucky, you will only go a little over it.
Same goes for the time that it will take to build the boat. But don't let that discourage you. It's all part of the fun.
Not really. No matter how well you seal the plywood, some moisture will get through. And then it's a mater of the type of wood veneers and the glue that was used to make that plywood. Only true marine plywood has the quality to last decades, and even it needs proper sealing to fulfill it's potential. No preparation or finishing can substitute marine plywood. However, exterior plywood can be good enough for your particular use. If sealed and treated properly, it might last longer than the rest of the boat, which is what ultimately matters. Since this boat won't be sitting in the water all the time, the plywood will have plenty of time to dry after being dissembled. So don't fret over it. Just give it 2 or 3 good coats of epoxy, plus paint or varnish, and you're good to go. It will last longer than you'll ever need. And if it doesn't, you can always cheaply replace it - that's the beauty of a modular boat.
Both Mellonseed and Anabelle are beautiful boats. Personally, seeing Anabelle gives me the same feeling in the gut that I get when I see an amazingly beautiful girl. Love at first sight. That being said, I am not sure how well any of these two boats would handle the transformation into folding version. Here's the frame photo of Anabelle... I might be wrong, but I don't see it happening. It just wasn't designed with fold-ability in mind. Maybe it can be done, but that wouldn't be my first choice.
I don't mean to distract you from your choices, but if it were up to me, I'd rather try to build a boat that was designed to be folded in the first place... Like Klepper Passat, or that Russian boat. Passat would be more suitable, because it is made of materials that match what you have access to. I don't think plans for it are available, but you could re-create it in Delftship from the photos and listed dimensions, with some liberty here and there. This is what I did when I wanted to make my own folding SOF. Of course, you won't get great resemblance from photos alone, but it might be close enough. I agree with Rumars that taking a proven design will save you a lot of time. But if you can't find plans for a folding SOF boat that utilizes materials you have at hand, it might be better to re-create a design of a folding SOF from general info and photos, rather than buying plans of a SOF that wasn't intended to be folded, and then trying to add joints. But I might be wrong about this, so don't take my word for granted. In any case, it will take some considerable time at the computer to plan it all in advance. The more you plan, the faster and cheaper the actual build will be. Delftship is great for hull shape creation or re-creation. For specific part design, you might want to look into some CAD software that can important Deltship files. I used Solidworks myself. But it can be done with Deltship too.
We're not exactly making this easy for you, I know.
Don't worry. You're doing great. All these decisions are important, take the time to make the right ones.
