This is my first /diy/ thread so forgive me if it's not good format. My brother and I were thinking about how we could make a catamaran by ourselves using pvc pipe as the outriggers and some sort of metal or wood frame and a sail. We did some displacement calculations and the size/amount of pvc we would need wouldn't be cost effective. Any ideas of other ways to make a catamaran? Pic related, found on internet
Yeah, I've had this on my possible project list for a while.
Basically, the best/most cost effective design is >>931274, but with skin on frame. you can build a skin on frame design for <$100 in parts, it's some pine wood, cloth (canvas is heavy, but cheap and works (from painter's dropcloths) but nylon is better, will be most expensive though), twine, staples/needle/thread, and a sealer. I've heard good results from deck sealers. Use mortise and tenons and lash them together.
Then, add 3 pipes across to anchor the sides together, add a leeboard to each kayak/canoe, and anchor a mast to the center pipe. Then add webbing between the pipes.
Mast/boom will probably be the hardest thing to do.
LOTS of displacement from kayak/canoes.
If your willing to put the work in working fiberglass/kevlar mat over a wood frame will be rewarding. Carbon fiber would be stiffer but way out of your price range.
You can source automotive supplies of fiberglass mat online.
If you are okay with your hulls being rounded (like a pvc pipe) a cheaper alternative is a cardboard concrete form. They come in 4 foot lengths and are $4-6. Makes displacement math easy.
Get a book on catamaran rigging. If you secure the base of the mast and hold the mast upright with wire you'll get better sailing performance (the leech of the sail can turn!) and it will be much cheaper/easier to secure the base of the mast with such a linkage.
Epoxy can be sourced off of amazon in the amount you'll need for $30-60. If you've never worked with it before it's magical (and messy)
Take your cardboard tubes, build a bow and stern out of something light (cardboard?) and wrap with fiberglass cloth. Soak with epoxy (this'll take a while) and then coat with epoxy until all threads are covered. Sand epoxy smooth and then paint with a marine grade paint.
If you don't want round hulls shape them (cardboard will work for this). You cut out the shape you want (it'll look like whale bones) and then pull the bones out (the shell will be strong enough with the right shape).
You can epoxy a linkage into the hulls or just straight up build the catamaran as a unit. Cheapest way to build a real boat.
Fiberglass mat is like $25-130 a yard depending on quality and source. The more you buy the cheaper it is.
All in if you build like this two hulls should cost you a few hundred dollars to finish off with a professional appearance and they should last 20-30 years.
To connect the hulls find a junkyard sailboat and cut two sections out the mast of the appropriate length (your "beam")
I'd recommend making a big daysailer with this project, build the hulls so they can be taken apart and get your mast rigging from a weekender type sailboat in the junkyard.
i know this is /diy/, but unless you're really, seriously interested in building boats it's probably not going to be worth it. you can get a second-hand paper tiger in decent condition for like $800-$1000 AUD, so i'm guessing around $400-500 USD.
i'd recommend buying one, learning how to maintain it properly, researching how it works and then thinking about building your own frankencat with custom hulls, THEN building one from scratch