I work from the UK where we cover our buttercreamed cakes with sugapaste (rolled fondant). Now I am coming over to the States for a wedding and have to make my little sugarpaste characters for a wedding cake. Thing is, the lady making the 3 tier cake does not do rolled fondant but leaves the cake buttercreamed. So, I am used to using edible glue (CMC & water) to stick my models onto my sugarpaste cakes. will this work onto buttercream? When I put sugarpaste decs onto my buttercream cupcakes it kind of melts and the colour runs so am scared the wedding cake will be disaster ville!!
You will need to use butter cream not glue to add your decorations to a butter cream cake. If the decorations are heavy then I add a toothpick in the bottom before they dry. I do this for all of my flowers if they will be placed on the side of the cake. If they decorations are not heavy then add a circle of butter cream to the bottom of your decoration. It helps add a little suction to the decoration after being added to the cake.
When you say sugar paste is that the same as gum paste? Because if it is, it should dry fairly hard and not go soft on buttercream. I don't use fondant to cover cakes...only butter cream and I use gum paste and fondant decor all the time using buttercream or royal icing to attach items. Because gum paste dries so light (flowers especially) I don't have any problem attaching with extra frosting. If you're attaching to a good crusting buttercream, you shouldn't have any problems.
Sugar Paste in the UK means Fondant. They generally don't use butter cream on their cakes. It's fondant or marzipan.