The hull uses 6mm Baltic birch frames and keel, sheeted with 1/16 Baltic . Without a proper workshop, I had to farm out the cutting of frames to my dad, who wanted to try his kit-built CNC router. It seems flimsy to me, but then again on my last tug (see the Orient Bay thread) I cut my own planks and could only get them down to just under an eighth-inch, so that was really overbuilt.