project curve / boolean

 From:  raytownmike (HOPPER)
8581.1 
I am attempting to create a geometry base label on a plastic tube, the tube has subtle curves and I thought O could use the project curve to capture a tight fit. Seemed to work of but then it seemed like my projected curve couldn't be used like I wanted (use as boolean object. Any thought on use of these projected curves to do more modeling?