I was wondering how to stack a ball shaped cake on top of a tier cake securely? The board under the ball cake would have to be really small? and use only one dowel? I would have to put a dowel through the entire cake? would that damage it?

Thank You

Put your ball cake together with the half line running horizontal, putting icing on 1/2 half to hold together.  I would cut a small slice off the bottom of 1/2 so it sits level and use a board for under it.  I would use a 6" board and 4 dowels under the board, and after you are ready to put the ball on you can ice the cake board or apply fondant to match your cake, if that is what you are using.  Which ever way you go, you can put a small border around your cake board as it will sit above the top a little.  If you like you can take the ball on the board to the venue and set it atop the cake, ice and apply the border then.  You could put a dowel through all of it but, be sure you have sharpened your dowel (wooden) to a nice point and then hammer it all the way through.  Hope this helps you!

Ok thank you! And I am delivering the cake so I would stack the ball at the venue just to be safe.