I've been thinking on this for a long time. When I was planning on working with wood it was fairly simple. Make a curved frame and bend thin plywood around it. 2 inch thick foam is different. It won't curve so easily. I've got to decide on methods for getting nice curves without weakening the foam too much. 

The first thought was to use a knife and straight edge to cut partially through the foam and remove the material between the two cuts, which opens a relief that should allow the foam to bend. This would require the cheapest tools, and should work fine. My next thought was to get a pottery tool that would cut along the bottoms and sides at the same time, removing the entire strip at once. I doubt such a tool is robust enough for the task, but I could make my own tool from steel, make it height adjustable, sharpen and harden it. Adding a heating element to this would also help it get through the foam, but would likely ruin the temper on the blade. I would likely go this custom route for a production setup, running many hot cutters side by side to make all relief cuts at once. I prefer to use standard tools and methods when possible though. My next thought was to just use my circular saw to cut shallow lines into the foam. This should work just fine, but due to the thin kerf of the blade, it would likely take many cuts. On the nose cap, which might be 5 foot wide or more, this would mean many little cuts and likely dull the blade rather quickly.

My very next thought was to get a small cordless Ryobi router and a straight cut bit and just carve a big channel out using a straight edge as a guide. I could clamp the straight edge down, run the router along it really fast, and get a nice wide channel of any depth I want. The router is already on my list of tools to buy and will be useful for many other tasks. I could use it to cut channels for wiring and plumbing, cut window and outlet holes, square up or round edges, and carve various recesses for things like switch panels and hinges. This is the route I will go when I start construction. I can get a router bit that carves angled sides and glue the channels shut to hold the bend. This assumes a suitable router bit can be found, but I suspect it won't be too difficult. I'm quite excited to own my first router, even if it's just a tiny hand held battery powered router. 

That covers the bending of a large panel quite well. As for getting rounded corners, I may just start by cutting them off with a knife and sanding until they're round. Being such thick material, it should be easy to carve and shape as needed. I have worked with foam and carved it before. It goes surprisingly smoothly once you have the process down. 

The more I think about how to work with this foam, the more confident I become in the design. This will also take me one step closer to working with fiberglass, as it's the precursor to fiberglass. I will likely make another version of this camper with foam and fiberglass in the future. Either to live in as an upgrade, or sell. I've had a dream of starting my own camper company for a while now, and this is the first step. Campers are a fairly easy stepping stone to boats, which is where I really want to be. I've already rebuilt a camper, I'm designing a custom one here, and I have sailed a very small sail boat already. I plan to build to marine standards as much as possible on my campers to get practice before I move to the west coast and start looking for boat work. 

The next big challenge facing me is how to make the cab overhang strong enough. I'll do a separate post on that one. I've got some interesting ideas to ponder.