cost ratio ply v alu

for a boat 30 feet in length can anyone give me a cost ratio between aluminum and plywood when epoxy, glass and paint are figured in

 

Are you looking for the cheapest or the best material ?

 

right now im weighing all options, time, cost and ease

 

Personally - and this in only my opinion - I don't like alu very much, not for a boat. I think it will be noisy and tin like and not as strong as glass. Glass and especially wood has a very warm and personal feel to it. I like glass, it would be my first choice.

Almost forgot to say - imo it's not what comes out the cheapest, it what works the best within reason.

Masalai is currently building a cat, have a look here
http://www.boatdesign.net/forums/boat-building/my-little-piece-peace-25962.html

 

At 30' aluminum isn't really competitive as a building material yet, so plywood is a cheaper alternative, but not the only one. Plywood is getting out of it's range of competitiveness at 30' and 'glass may be a better choice. 30' in steel is still on the small side to make it viable, but one off 'glass is a consideration.

In the end, the choice of hull material has a fairly small impact on the total cost of the project. Aluminum, being such an expensive material, needs to use it's weight savings advantage to offset it's initial cost, to make it viable. Steel is the other way around and need the displacement to be fairly substantial to warrant it's strength and low cost advantages in larger sizes.

The hull material can be fairly subjective at 30'. An expensive aluminum job, but light, maybe a pretty wood veneer over plywood hull, finished bright, possibly a foam cored 'glass speedster or a bullet proof solid 'glass hull, a cold molded or strip plank round bilge or best yet for looks and charm a glued lapstrake.

It's a crap shoot, so pull out a coin and start flipping.

 

its a sharpie design so its all slab sided and flat bottomed no forming or complex layout needed

im comfortable working with metal and thought construction would go faster than having all the labor wood seems to require

my thought was flat panels and extruded shapes for framing and stringers
with interior partitions and interior decking of ply

im a strictly form follows function guy.

in fact i only plan on 2 cruising comfortably with more than 2 strictly a day sail

my criteria is ease of getting in the water, ease of maintenance, cheap to sail safe to sail, easy to sail,

its a proven design in ply so im sticking closely to weights and balances in the final build

and fiber glass sends me climbing the walls