I'm going to ice two tiers tomorrow night in buttercream. I need to take them on Sat. morning at 9:30am. She wants each layer wrapped in a strip of fondant (to mirror the ribbon-look). I was planning on a 1" strip in 1/8" thickness. When should I attach strip to cake? Late Friday night, or very early Saturday morning? I've never put fondant pieces on buttercream before. Will it get gummy? I will refrigerate the cakes Friday night. Any problem with that fondant strip in the fridge?
Thanks!!!

I don't know if I would put them on Friday night since you are going to refrigerate the cake. If you weren't, I would say you could do it Friday night. Refrigeration makes the fondant hard. Anyway, you can use water, extract, or really any paste or liquid. My fav to use is either more buttercream thinned or piping gel to adhere the fondant to crusted buttercream. If you can put the fondant on while the buttercream is still soft, you won't need any other "glue".