Well, yes, Carl...

I can see that you've already done the first part of the dance with Charlie, so I'll give you some feedback as to what kind of options you might have for a boat as you suggest.

You can build the foam core in much the same fashion as you would for a wooden stripper, if you want. Setting up a series of sections/stations on a strongback and then stripping on the foam prior to fairing and eventually laminating with your chosen reinforcing cloth.

That way will work just fine, but it takes more time, has much more in the way of seams that will need to be glued/bogged prior to being faired. Another method is to build the hull in vertical halves on a female mold surface. The foam can be easily bent around any curvature you have designed with just a bit of heat from the standard heat gun used in boatbuilding. The wide sections of foam are glued along the adjoining seams, faired and then glassed or otherwise, as you desire. You then release the foam glass half from the mold. Once cured to handling state, the two vertical halves are joined together with a taped seam inside. Place the boat in hanging cradles or on a stand that matches the profile of the hull and fair the exterior. The entire outer surface is glassed in overlapping cloth wraps.

Whammo! the boat is essentially ready to test as a form study.

You are correct that foam is far easier to fair than is wooden strip material.

You are also correct that the boat does not have the same puncture resistance, as would a hull from different material. Your statement that you may not need to have such a hull dynamic is also more than correct. Wander through the builders sites for the guys who make the ultra fast flat water kayaks at a world class level and you'll find that they have long ago moved away from wooden cored hulls for their machines.

The business now is all about foam and NOMEX (honeycomb) cores with carbon laminates inside and out. Their boats are also built in beautiful, female molds (tools) with the carbon coming from the prepreg variety of the resource. The carbon is placed in the tool, the foam or NOMEX and then more carbon. The whole thing is then bagged under vacuum and rolled into a huge autoclave for cooking under pressure.

Out comes the bagged and cooked hull ready to be trimmed to the molding lines and then glued to the deck, which was done the same way. The joining is typically done with a mega version of methacrylate adhesive (Plexus and Sikaflex being the most commonly used glues) and then it is fitted out with seats and rudders, etc. as needed for the customer. Sometimes the laminates are flooded with resin while in a bag under vacuum in a process called resin infusion while using the same cores.

No, these craft are not very puncture resistant. Then again, you don't usually see them out banging around in a rock garden off the coast of Oregon, either. You also don't see them making hard shorebreak landings. They are very repairable once the technicians doing the work learn about the different materials.

These boats are very, very stiff for their weight and they weigh next to nothing. The carbon skins, in concert with the Nomex or foam cores, give the boats fabulous stiffness. They represent the highest order of kayak construction available right now.

Most production boats, of all types, are made in this fashion. The technique is used by Searay power boats, as well as Gunboat catamarans of the 62' variety. It's also used to build lots of smaller recreational craft nowadays, as the laminating is being done in what is called closed mold technology. This reduces VOC's in the atmosphere and has become, more and more, a hard line regulation to which the manufacturers must adhere.

As I said before, wooden boats still are very good for what they are asked to do. They just are not the only way to build a quality homebuilt boat for those who wish to explore the possibilities.

If you are working with students who are likely to go into the boat building/design industry, the knowledge they will gain will be completely transferable across the table to a working environment. I wish I could say the same for wooden boat building, but it is just not very true these days.

I love wooden boats, love to work with the material and love the way they look when finished bright. There are other materials to use though and the landscape is wide open for that potential.

If you do build a foam-cored craft, then look to buy the seconds from Noah's. They are much cheaper and will work perfectly for a project like this. Also, don't buy exotic cloth until you get settled with the process. Try not to laminate Kevlar on the exterior of your hull, as it is a nightmare to repair when the time comes and most of all.... have as much fun doing this as you can.

Here's a photo of the process mentioned, as well as a link to the site from which the image originated. This happens to be a 22' trimaran float, which is not too different in overall size when compared to an expedition double kayak. The build technique is virtually the same. While you are there, take a look at all the images. You'll see that a fairly complex project, like the trimaran shown, can be done with competence by amateur boat builders without too much trouble.

Need any specific help in the process, just write me offlist. I'll be happy to help you out.

Chris