Another question about the door is if it's hollow core or solid core, and if solid core, if it's a fire door?
If hollow core as probably not the case in a professionally built booth than it warping should be sufficient grounds to replace it either with a real door that will both
block sound and delay the spread of fire especiall if a fire door with at least a 30 minute
rating - long enough to
clear the audience. Otherwise, if hollow core and warped it is probably thirty bucks for a new one.
If solid core and expensive, assuming the door opens inward into the booth and the bow is in the middle and towards the booth thus, and assuming the outside
face is decorative or shows, you don't have much of a choice for straightening it. If not too sivere you could shave some off of the stop
molding above and below so it conforms better to the door's shape. Otherwise if not seen by the audience or if it can be done in a way that won't be noted much, you could add either some steel
channel, L' steel or I beam to the
face in
thru bolting and screwing that door back to straight. Better yet,
Unistrut is more ridgid and light weight. At this
point, I assume that the entire door warped in the center and you might want to add a middle hinge after the door is straight. This will help prevent further warping. Perhaps a air conditioning thing, is the booth really cool and not well ventilated?
Given the door opens outward, bolting
unistrut to it should be a safe bet but one might ask the management before
hand.
Still easier to on a middle of the door warp to just take some of the stop
molding off at the top and bottom and live with the warp thus. You can also look into adjusting your
strike plate outward some to recieve the new position of the door.