new kid on the block

[TomSawyer]

Hi! my name is Tom and i am planning to build my own all plywood boat, 32' long 14' wide, 9.5' high, Catamaran style cabine cruiser with two diesel outboards...

I'm new to this so be indulgent, I'm JACK OF ALL TRAIDS but MASTER OF NON

and forgive my grammar I'm from Quebec in Canada (French Canadian)

So in short I'would like some advice on this project (Hull design, materials, etc...)

I did a bit of home work, I'plan to build the craft in my yard (outside) the with and hight is about the max I can go, (road transport regulation without a certain permit), I'm at half an hour drive of the ST-Laurens river so road traveling with the boat is required (2 times a year becaus of our cold winters)

I found out that a plywood boat is cheap but needs to be dry docked every year for hull maintenece so i am preparing space on my land (at home) to store my dreame boat...

I'm not sure in what I'm getting in to but please feed me with what ever you might have in mine that would keep the GRIMLINS out of my project ha ha!

Estimated time = 2 years (since i ownly can work on it in summer time)
Estimated cost = 15000 $ canadian (just the boat) not the luxury, engine, electrical. plumbing, etc...

Thank's in advance...

[terhohalme]

Welcome on board.

I will estimate your building time over 4 year (approx. 4 tonn of boat) and your cost over $60,000 US. Don't be scared, this is just my opinion. Send me this estimation after you have done it. If these numbers are too high, I'll be very humble.

[TomSawyer]

Wow!! if you didn't want to scare me you missed ha ha!...
I've never estimated that much time, as for the price I was talking (just the boat) lumber, screws, epoxy and glue...

I've calculated 150 sheets of 3/8" plywood (ordinary plywood for the first layer) and marine type for the last two...

after a good spray foaming then a 3/8" layer inside (all fiberglass re-enforced joining inside and out) then a multiple coating of epoxy outside

my crossmebers would be at every 24" with 3 full pannels (cabin walls) every 1/3 of the ship.

so I calculated 10000$ of lumber
1000$ glue
2000$ epoxy and paint
2000$ screws (stainless)

nothing els, no furnitur, no windows, no nothing, just the hull and cabin...

The rest will come as I go

What I really need to know is 4 tonn 32' long by 14' wide catamaran style is a good plan or not (with a split hull will I have a good DISPLACEMNT) I've calculated about 2' in water line (fully loaded)

Thanks!

[TomSawyer]

Thanks Hoyt for the welcoming

I've did some findings on the net, about marine type plywood and ordinary, and my conclusion was that ordinary weather graded plywood would do the job as long as I keep it sealed...

now I must find a good G type catamaran hull design so I can start working on my project befor Whinter knoks on my door...

[hoytedow]

Originally Posted by TomSawyer

Thanks Hoyt for the welcoming

I've did some findings on the net, about marine type plywood and ordinary, and my conclusion was that ordinary weather graded plywood would do the job as long as I keep it sealed...

now I must find a good G type catamaran hull design so I can start working on my project befor Whinter knoks on my door...

Water will find a way in. Only use marine grade if you don't want large convex warping in you boat.
L'eau sera de trouver un moyen po N'utilisez qualité marine si vous ne voulez pas convexe grande déformation de votre bateau.

[gonzo]

I think that getting a design with materials specifications and basic construction details will be your best investment. Have you checked some like James Wharram?

[TomSawyer]

I understand water infiltration if you keep the boat in water all year long, but in my case because of our cold whinters, it will be in the water at the most 3 months so I'm obliged to dry dock the boat every year, (giving me a chance to maintain the hull in autumn and spring)

I don't believe leaking's going to be a problem, what I'm most worried is the whaight and where is going to be the water line, since I will test everything once finished...

BTW to answer Gonzo, this is why I came to this site in the first place, to get good information about designing my boat... (not the material but mostley the form)

I found out that the most comfortable and stable hull design for shallow and deeper water is the G type, (correct me if I'm wrong)

I dont want a speedster I want a CADILLAC ha ha!

[TomSawyer]

OK let me explane my plan...

I plan to build a motorised (two diesel outboards) catamaran style cabin cruiser, why catamaran? because of the stability in the water, why motorised ?, because I don't plan on making long trips espetially NOT out to sea..., but why two diesel outboards ? for redondency and chaeper to bring the engine to a mecanic then bring the mecanic to the boat, and why a cabin ? because I want to camp in it.

I' m a good carpenter, I build a 60X30 house (completely alone), renovated another with my wife, so I'm not afraid of my skills

So I plan to build it with 3 lyers of 3/8" plywood on the outside and one layer of 3/8" plywood inside exept for flooring (1"), with urethane foam sanwiched in the middle, it will be 32' long 14' wide and 10' high (hull and cabin), crossmembers every 2', one full crossmember in the back, and two others for cabin walls at every 1/3 of the boat, all the joints and edges will be fiberglass re-enforced (on each layer) and inside to, than lots of coats of epoxy (as manny it takes) to get a nice ergonomic clossy finish

I was even thinking of finishing the paint job with some sort of clear coat like for cars

every peice of wood is screwed (stainless) and glued of course...