It'd be a good idea to confirm what you mean by "through the plates"? You only use this method if you are using CARDBOARD cake boards and not anything plastic between the layers. If it's not cardboard, it'll go very badly lol. For sharpening the dowel, please be sure to use a sharpener that used only for cake dowels so avoid contamination by any substances that aren't food-safe. HTH!
2/3/13 at 3:12pm