I will be making a wedding cake for my sister and the total amount of batter required is 35 cups.  I was wondering how I will go about doing this.  I only have a 5 qt Kitchenaide mixer at home and that won't be big enough to do it all at once.  I have seen people use a large 5 gallon bucket and a drill with a paint mixer attached.  Is that safe?  what other way can I do it? Please help!!!

Are you pouring all 35 cups into one cake pan?  I would say just double it and make it as you go.  My mixer holds my cake batter doubled, I fill my pans accordingly then make more.  =-) I've never tried the paint bucket method but am unsure why you would need all your batter done all at once......  curious to hear other replies

Yes, just make 2 batches of batter at a time.  That's what I do.  No need to get fancy with a paint mixer.  You can also make the batter ahead of time and freeze it in Ziplock bags and then defrost it on the counter when you need it.

I'm pouring the batter in two 16" cake pans so I wanted to mix all the batter at once to save time.  I guess i can break the batter into two parts and mix is twice.

If I freeze the batter, I will have to remix it correct?

I don't see any reason to make the batter for the two 16 inch pans at the same time.  You will only want one in the oven at a time anyway.  So make the 17 cups  for one 16 inch pan, bake it.  While it is cooling to turn out of the pan, let the pan cool and rewash it you can make the other batch of batter.

Oh heck, I wouldn't want to wait to bake them separately. Unless you don't physically have the room in your oven for two, or you only have one pan, toss them both in, and rotate halfway thru if necessary.