i agree with cali4dawn, the water HAS to be very, very hot. i boil enough water to fill a pitcher...like one you would use for kool-ade, or lemonade.
i tried a glass-big mistake!! i went to pick it up and boy did i regret it!
one thing that you have to do when smoothing a cake is, do it lightly, and quickly. the more you play around with it, the more trouble you'll have. this is something that you have to practice!!! no, it's not a gift from above, we are all gifted at cake-decorating... but it's a gift that we get better at the more we use it!!