I started this a few weeks back...it's a block of expanded foam that I bought from a sign maker I know. So far, I'm learning a lot more than I'm getting done. First off, what defines a tiki from just a usual sculpture and, secondly, how foam cuts with the various tools. For now, I'm using a hot knife and hot wire cutter. The keys here are patience and ventilation. You don't want to go fast and accidentally burn yourself and you need the ventilation due to the fumes that melting foam causes. Overall, though, I'm having a blast and the work is coming along well enough given the amount of time I've spent on it...just about 2 hours for now.