When I made the first reaper I wanted to make sure that the end-product didn’t look like a tent with a skull on it, so I added a an aesthetic rib-cage (a chest plate) to the front. This was something that I had been thinking about for a while but didn’t have any real plans for. I ended up spending an hour or so drywall-screwing and duct taping together some PVC pipe and sheet metal. The end result was passable, and I liked the effect, but it was not my best work.
The new chest plate needed to be light-weight and durable so I went with fiberglass over foam. To get the correct, scale shape I used my life-sized plastic skeleton and a ruler and made a drawing on my shop floor (scaled up, of course) using sidewalk chalk. I then covered the drawing with plastic wrap and duplicated the shape in expanding foam.
Once the foam was cured I pulled off the plastic wrap and carved off the non-rib-cage-looking bits. Since the foam ribs were so thin and would not keep the intended shape I needed to hold them in shape while the fiberglass was applied. I used a piece of galvanized sheet metal bowed across a trashcan. I duct-taped down the ribs (I should have used masking tape) and started the fiberglass. Having learned my lesson last time I opted to do the work in the open air of the driveway rather than inside the shop.