I'm building a scenic piece for an annual fundraiser and want some input. I almost always build scenic elements for very short runs of shows that only go one place for two weeks. I use a lot of disposable/reusable lumber for building sets. This time I'm actually building a sturdy, lifetime piece and I'm not sure how to best spend the money.
The main, flown-in scenic piece is going to be a 8' diameter sunburst with a 4' diameter replica of the actual crystal award. Think like the Oscars; they have that 12' tall Oscar statue prop. The sunburst will likely be made of a resin-coated structural foam like Diab or honeycomb in two semi-circles that can be hinged or disassembled into two pieces and look something stylistically like this. So, three pieces - two semi-circles for the sunburst, then the crystal award mounted in the middle:
Our award is Swarovski crystal and looks like this:
In trying to turn this hand-held award into a 4' diameter replica, what should I use? Polycarb? Plexi? Acrylic? How about the sunburst? Honeycomb? Diab? I've been itching to buy some vacuum bags for laminating. Already have the pump.
Goals:
- annual use for one night with 364 days in storage (I'll likely build a storage "bag" for it)
- must be transported to and from another theater about 5 miles away
- hopefully be able to be used for 10 years or so. So if it gets scratched I'll need to be able to polish it
- will likely have a perimeter of LED tape, so think also about how they refract/carry light.
Acrylic can be re-polished much easier than polycarbonate if you scratch it, and the ease of scratching is about the same. If it is unsupported the better strength of polycarb is worth considering. The open-ness of the sunburst makes a very difficult layup in fiberglass, I would use aluminum for those pieces.
TurnerX19 said:
Acrylic can be re-polished much easier than polycarbonate if you scratch it, and the ease of scratching is about the same. If it is unsupported the better strength of polycarb is worth considering. The open-ness of the sunburst makes a very difficult layup in fiberglass, I would use aluminum for those pieces.
Good to know. I have a bunch of recycled clear plastic sheets in inventory at the theater but I have no idea what it is, other than I know that the stuff that smells one way when you cut it is easy to crack, and the stuff that smells another way seems more flexible, but other than that I've never been able to pinpoint what the material is.
For the sunburst, my thought was to cut the "rays", lay up some epoxy resin, and put them in a vacuum bag several at a time. Then make a central 4' circle of the same stuff and bag it as well... then assemble the rays to the central circle with fasteners and more epoxy. Then I found some of those shelf brackets for glass shelves in a drawer, so I could permanently mount them to the sunburst. Deploying it would consist of opening up the two halves of the sunburst while holding the clear plastic to fit into those brackets.. Rig it, fly it, done.
The glass standoff shelf brackets I have are much like this:
so I could assemble things like this:
Smell is the official way to tell one plastic from another. Another technique is to break it, which you have already tried. The brittle stuff is acrylic, the stuff you can bend is polycarbonate. Now memorize which smells which way.
I have done a fair amount of composite work, and lots of aluminum fabrication. I also have access to a 4' brake and shear. In aluminum that sunburst looks like a few hours to cut, fold and drill for rivets. In fibreglass or carbon it looks like a few days to make the rays. How many molds do you make? Molds deteriorate pretty quickly, so you need multiples. The circular core would be easy to duplicate in composite if you needed to make multiples, but for a one off , once you make the mold you have made the part.
Really cool project anyhow.
I wasn't planning on molds. I was going to cut structural foam into "rays", maybe throw on some woven glass, soak it with resin and throw it in a vacuum bag overnight. I can trim off the edges later.
Thanks for the tips.
