I've shown some finished pictures of these in my shop rehab thread, but I don't think I ever showed the skeleton. The ones in my main shop were 2 X 6s because the ceiling joists were 2 X 4s. The assembly/finishing room roof was added to the structure when the house was built in '85, so the ceiling joists are 2 X 6s here, and therefore the skeleton's ribs had to be cut out of 2 X 8s. I cut the shop ones with a jig saw, but used the bandsaw on these. Much faster, much easier, and a lot better cut. I took a piece of flexible plastic that was 24" wide and put up between the joists (24" on center). This created the arch, I copied that and cut out a template out of 1/2" plywood. Each rib is 24" long, so that gives a notch that sits on top of the joists. DSCN2231.jpg This keeps the arch a consistent spacing from the bottom of the joists. I screw the skeleton pieces into place from the sides of the joists, 2 screws per side. I use a couple pieces of the 2 X that was cut for the arch to make the deadmen helpers. This allows me to do this by myself, though it is still a struggle to keep a flopping piece of Glassliner, you can get it at Home Depot in 4 X 8 sheets, that is cut to 24 X 96, in place to get a deadman started. DSCN2234.jpg The Glassliner is textured and shiny. It also conforms to the shape of the arch very easily, yet being a fiberglass material, is fairly strong. I attach it with 5 #10 1" long pan head screws at each rib, starting with the center one first, the moving to the middle ones on each side, then the bottom ones, in that order. DSCN2232.jpg Helps the Glassliner conform to the skeleton better. I had just enough material for the basic reflector. Should have cut it about 10" shorter so I could have cut out my end caps but it would have been a little shorter than the ones in the shop. I'll have to get something else that will work now, cause I don't think I'm going to spend 30 bucks on another 4 X 8 sheet of this stuff!! Not just for the end caps. I'll probably get some 1/4" plywood and paint it bright white. I'll show how this is done in the coming weeks.
This idea was born out of a short ceiling height in this shop building. About 7' 8" in the main shop, 1 1/2" shorter up at the bench and cyclone closet because the floor in this section is raised about 1 1/2". (The building was originally a car port, and this section was the enclosed storage closet area.) I had to do something so that the lighting did not make a bad situation worse. I thought some of you building shops in you basements might be able to adapt this idea to help you if you also have a lower than desired ceiling height. Jim.