Temporarily lock a thread?

[Hawkeye]

Is it possible to lock a new thread from other users adding to it until the other is finished adding all the content. I would like to start a thread that will take several days or weeks to add all the content and I feel it would be cleaner if I could post everything prior to any comments being added. Once all the content is added in then unlock it to the group.
Thanks,
Marty

[Hawkeye]

And, how do some authors post a photo add wording, post a photo add wording, repeat, repeat, etc?
Thanks,
Marty