It very much depends on the context. I think that the first of the following two sentences is possible; the second is not:If so, can we apply the usage of 'will' with all the time conjunctions such as 'before, while, as soon as,...etc?
He wants a guarantee of protection before he will give us the information.
He usually has a glass of milk before he will fall asleep.
I can't at the moment think of a good example with 'while' in its 'during the time that' sense, though perhaps this works:
He seems to be prepared to listen. Let's explain it while he will listen - we may not get another chance.