Using the existing concrete slab that was the floor of my old house, I have secured 4mm angle brackets with dynabolts. To each 9 pairs of brackets, I have screwed a 650mm piece of 100×50 cypress pine.
Onto each edge of those 9 crosspieces, lengths of cypress 100×50 make the frame that the building stock is screwed to. The cypress pine were from a shop in Moree that my brother and I refitted several years ago. The timber is really old, hard (brittle) but straight and resistant to rot and termites.
The final building stock screwed onto the outside is the 200×18 hoop pine that will eventually go into the frames that join the two hulls together.
Strongback for boatbuilding