Thanks so much for your help. The solution i used was sumerged the two sides (bottom of the pipping and up of the soap) in transparent melt and pour and stick perfect! This is the result:
Hi, first of all sorry for my english. I made 100 soaps for a wedding and to try be more efective, i make the 4 loaf and later (1 or two days)make the piping. So the piping does not stick in the loaf of soap.. i already read that this happens when is not inmediate the piping ( never again!) But...