I'm working on a cake for Mother's Day. I crumb coated a 9x13" cake and piped the grass tip #352 going in a up and down pattern on the sides of the cake. When I checked back on it a few hours later, some of the frosting from the sides of the cake came off. I should be able to scrap the frosting and reuse it. Any suggestions on how to make the frosting stay on the sides? The only other thing I could think of is to pipe it directly onto the side in several parts as oppose to trying to make it go up and down in one motion.