Ben needs a waterproof kite!
Hint 1 of 6:
Only one item in any time is designed to be waterproof. Make sure to pay
close attention to the item descriptions.
Hint 2 of 6:
Something in this time can be used to keep away rain.
Hint 3 of 6:
Red Edison's lab coat looks like a raincoat, but only employees can take that
coat.
Hint 4 of 6:
You need to give Red Edison proof that you are working for him.
Hint 5 of 6:
Or at least proof that he needs someone working in his lab.
Hint 6 of 6:
Give him the "Help Wanted" sign from the motel's window in Bernard's time.