Carbon fiber Tips Please

[arzzeee]

hello i have been looking in to building my own boat and i was wandering if i was going to set out a mould and where to use carbonfiber how many layers and what gram should i get?
i want to build a wide 20-24 foot boat for skiing

 

[gonzo]

There is no good answer to that. Carbon fiber, if you want the expense and complication of using it, is only beneficial if the design is made for it. What do the plans specify?

 

[arzzeee]

i dont have any plans unfortunately i find it nearly impossible to find what i want :/,, but i know carbon fiber is stronger than fiberglass so how many layers does a large speed boat have?

 

[SamSam]

2 to 15 depending on the hull shape, the location on the hull and/or any other reinforcing structure incorporated into the design. It also depends on whether you use a solid laminate or a cored composite.

I don't think anyone uses carbonfiber to build ski boats, so you'd be the first.

 

[PAR]

Welcome to the forum.

Before you start specing materials for your design, don't you think you should spend some time studying the appropriate disciplines first, maybe such as material properties, hydrodynamics, engineering principles, etc. I'm not sure how they do it in Queensland, but else where in your country, this is usually the case.

Okay, I'm being a little coy, simply put, your questions are of such a basic nature, you'd be best advised to buy a set of plans and adhere to them religiously. Designing a boat or modifying an existing set of plans for a different hull material, does require some skill and education.

 

[arzzeee]

im doing an engineering degree so i do have some knowlege of properties of carbon fibre and how it reacts and i do have shape and hull designs just with out the plans so i have no real way of seeing how much strength is required in some areas and there is a company that still makes carbon fiber speed boats however not in australia, and they guard there secrets well they've been making them since 1998. i was just wandering is all

 

[FMS]

Which engineering discipline are you studying?

I know a civil engineer works through a textbook that provides a clear procedure to specify steel sections, and then another textbook that leads a student through designing composite steel and concrete structures. A civil engineer would be disappointed to find that no equally detailed textbook exists for high-tech composites for powerboats that I know of. One reason is that carbon fiber powerboats are only a tiny fraction of what a naval architect designs and this is a tiny specialized industry compared to civil engineering.

Powerboats that use carbon fiber layups fit into three groups:

1.) they are thoroughly engineered by one of a few naval architects that knows how to calculate a highly optimized laminate schedule based on experience

2.) carbon fiber has been added to an existing layup schedule with some trail and error

3.) carbon fiber is used decoratively to say it's "carbon fiber"

The first two are guarded trade secrets. The difficulty is getting strength and stiffness optimal with sufficient safety factor, without cracking or other structural or finish problems over time, and with as little weight as possible. Adding a stronger piece one place can create a problem in another. Building stronger than necessary results in an overweight boat. Building with too little, and stress cracks show up over time.

 

[redreuben]

Go to a materials supply company, they should be able to re calculate a standard grp layup for carbon.