I am making a sombrero cake and made the rim out of gumpaste. I let it dry over a pasta bowl for the rounded look, however, my perfect circle did not end up drying that way.

When I flipped it over the edges are not even - I guess it must have slid down further in some spots and dried that way.

Is there any way to fix this? 

I was thinking sandpaper to shave off the uneven top and level it out, but I wanted input before trying this. 

Thanks!

AI doubt sandpaper will work. I'd just make another one. If you do try the sandpaper let me know how it goes.

Sand paper works great on gum paste.  Do you have a pic of the area you want to fix?  I am guessing at this point but you want to be care not to go thin if you're going to put weight on it so it doesn't snap and break.

Jeanne
 

A