So here goes... I would like to build a caravan and I assume (but ask the question anyway) is it practical to build a BIG box using vacuum induction forming techniques or do I have to create it in sections and I have a fairly good understanding of bonding and area vs. strength and concepts like tensile strength and stressed members, but what I don't get is where I start. For example do I plan to build a nose-cone and tail then fill the middle in with square flat sheets?