how to build a fake proscenium?

[kennethsmith]

I'm wanting to build a "fake" proscenium arch that will sit behind the main curtain, and can be flown in and out. The main curtain can be drawn partway, revealing a different, more elaborate proscenium. Then, the main could be opened all the way, and the fake proscenium flown. I'd also like to hang some "fake" curtains from behind the fake proscenium.

The regular proscenium is 33' wide by 20 ' high. The second (fake) proscenium would be about 18' high by 22' wide.

I could build the whole thing out of Luan, but I really worry about it warping over that span. I could build the top, horizontal part out of luan, then for the vertical legs, use 5' wide canvas/muslin legs with pipes in the bottom.

What do you guys think? Is there a better design?

This forum is so helpful -- thanks in advance for loaning your expertise!

 

[StradivariusBone]

The Bill Raoul book has some ideas for a false pro. I think the warping issue has to be countered with good framing. I've used hogstrough or other stiffeners to fight buckling. IIRC one variant was using hollywood for the torms/legs of the arch and then flying the arch piece over the top of the legs which are ground stacked and supported with stage jacks. At 18' though you might want to consider at least tying off overhead if you go that route.

 

[Van]

Use the search tool on the top Right corner and search for "False Pro" you get a lot of hits. There are a ton of ways to do this. If you are flying the entire thing pay particular attention to the warnings and suggestions of how to bottom rig the flat so they are properly supported for flying. I've found Broadway style flats with muslin covers work well for a false pro from the simple standpoint of weight. Warping, in either direction, can be countered by running vertical and horizontal strong-backs/ t-backs/ hog troughs/ whatever they are called in your area, to the backside of the framing.