(Ft. Myers, Fl)
If you have painted a picture that you do not like and wish to re-use the canvas, you can remove the old painting by spraying it with oven cleaner.
After 20 minutes or so remove the oven cleaner with paper towels. Then go over it with dampened paper towels. Next make sure the canvas is dry and then coat it with white gesso. Once it is dry you can paint a new painting on it.