boat construction

I have been drawing the same boat for about 3 years, and now I am ready to begin construction. I work at a boat manufacturing facility as a fabricator, my supervisor has built atleast 5 sailboats ranging 20ft-40ft. I ask him for advice and recommends that I use foam sheets to develop a shape of the boat. He said would I able to sand or fair it for smooth surfaces to the desired shape after I apply the sheets to the skeleton and the laminate it for strength. I was wondering what type of foam sheets is he referring to?

Thank you!

 

He will be the best person to ask what he is talking about. Depending on what you are trying to do, there are many options. For example, is this a plug or a one-off?

 

Hey Gonzo!
Thanks ! I was hoping to use it as prototype and if performance is well, use it as a plug.

 

There is a big difference between a drawing and a design. The drawing should be the end product of the design. The design will take into consideration building materials and techniques, planned use of the boat, area to be used in, total weight (displacement), target speed, necessary power, stability calculations, compliance with regulations, etc. As you see, the design process should've given you the answers. Trying to find building materials to fit a drawing is not a good way to go around it. The whole design should take all aspects into consideration. You may find that the drawing needs to be modified to work with foam or solid lamination. Plugs are usually build of wood or wood/fiberglass.

 

As Gonzo as eluded to, you "design" the boat. This includes an engineering approach, usually first, with aesthetics coming much later. The process usually starts with an idea of the shapes you want to employ, which will be driven by the boat's use, owner requirements, etc., as some are better suited than others. With this general idea of shapes and volumes, you work up an arrangement plan, so you can roughly place the various bits and pieces, trimming and balancing out the chosen hull form. Now you have an idea of weights, placement within the limitations of the hull form chosen, so you start refining up the lines to nail down the volumetric and balance, with an eye toward accommodation and equipment installations. The construction details pretty much select themselves as you go through the process, because you've made multiple decisions about build type, it's appropriateness with the hull form, build method, weight requirements, etc.

The last thing you want to do is attempt to reverse engineer the scantlings. This is much harder in terms of getting good weight and incorporation into the build. It's sometimes necessary on a significant build or restoration, but only when you "have to", not as a rule, simply because it's so much harder to do.

Foam is a good way to get a one off hull, but you have to ask yourself "are the shapes I'm employing, the ones best suited for what I want out of the boat". This is the very first part of the deal, other wise you'll refine and fair shapes, that aren't particularly well suited and it's just as easy to build a boat that sucks at what you'd hoped, than one that nails it.