Working with stucco

Anybody have a good tip or trick for creating a sharp edge on either end of the oven with the stucco? I thought about using a piece of the left over styrofoam used for the voids and pushing it up against either end to for a kind of mold. thanks

I realize this response is well after you asked the question, but I will respond anyway since I just finished this process with my oven and dealt with the same situation. What I ended up doing was to make sure the stucco was wetter than normal (yes, that’s counter-intuitive, but it ended up making it more pliable and “stickier” than the stucco mix for the sides). I then took two flat edged trowels, held one firm against one of the side of the oven and used the other one at a 90 degree angle to form the sharp edge. the trick was to move the trowels laterally sliding them away from the edge I just made. this technique did not work so well on the base scratch coat, but worked much better on the second coat.