Need help with determining the construction reuirements:

[Navy Dave]

Hello,

I am a MBA student at Southern Methodist University - Cox School of Business. I am working on a five-year business plan project for a start-up boat manufacturing company. Not only is this a required project, but also I would like to see if this is a feasible project to actually pursue.

My question is how many layers and of what kind (mat, weave, weight?) of Fiberglass media would you recommend for a 14.5' planeing, air-entrapment hull, given your experience?

This is only for forecast financials. I have sourced all my materials based on estimates based on scraps of info gleaned here and there, but I am unsure if my estimations are accurate. Inaccuracies in materials requirements can have a significant impact in my financial projections.

The boat will be a 14.5’ planeing catamaran powerboat, with a stepped hull and center pod. I expect the boat to utilize a 50 hp motor.

The primary intended use is flats fishing in protected waterways.

The target weight is 700-800 lbs.

There will be two models:
1) Fiberglass vacuum resin infused
2) Kevlar/Graphite weave resin infused

I have no idea of material weight to use, type of media (mat, weave, etc)

The measurements are:

14.5’ long
7’ wide
3’ gunwales

I do not have any cad drawings, as the time frame is very tight on this project. If the numbers workout, I will continue to pursue this project further.

Let me know if there are any other details that need further clarification.

Thank you once again.
Dave

[DavidJ]

I think the reason you have no responses to this post is because you are asking a very big question. Essentially somebody needs to at least do a preliminary design to answer this question and you have left it very wide open as to what you want.

Don't forget to check out the pros and cons of different resin systems. Don't forget your gelcoat(or perhaps paint) and spraying equipment. Check out cores. If you are going high speed you might need the stiffness and weight reduction. If you are doing infusion remember to price out the tubing, pumps, valves, and plastic required for bagging - it can get expensive. Kevlar and Carbon are more useful in advertising that in real use most of the time in small boats. They are harder to repair and generally don't last as long. It might be advantages to do like the kayak manufacturers and sell both a fibreglass version and a more expensive "racing" version made out of the exotic materials. Buying the different rolls of material won't really change your costs much. The stuff lasts forever and it doesn't take up much storage room. Building the moulds, setting up the shop, and
labour will be much bigger costs.

What you should do is contact companies already building similar vessels and ask them for input. They might not be willing to give specifics but they should get you in the ballpark. This is a decent textbook on composites and it is free on the net: http://www.marinecomposites.com/ If worst comes to worst and you have to do some calculations I'm sure if you search hard for scantlings you will find something on the net. The ABS rules are free on the net, but they aren't exactly quick and dirty: http://www.eagle.org/rules.html

Good luck with your project.