Building the jig wasn't that big of a deal, but it was fussy work that took some time. I made one change from the plans, on advice from other builders, and lifted the "top" of the turtleback shape 1.5". This will give more inside headroom and hopefully a pleasing curve when it comes time to do shaping. But this step also required me to make new templates, so I started by tracing the templates on new paper and extending them to make the additional room. The jig pieces themselves were cut and assembled per plans, more or less (I used some scrap wood to assemble it so some of the side supports were slightly different sizes. No big deal.) For side support, John and I found some thin aluminum flashing material at the local Home Depot (fortunately there's one right around the corner from the hangar!) and used tin snips to cut long, narrow strips out of it. These we laid into the form to support the pieces of foam.