I prefer to mechanically strip the paint off of a frame set. Using a drill motor and different rubber flapper wheels, or whatever they are called, I just wear the paint away. I can strip a complete frame and fork set in a couple of hours. Do not use the wheel close to detail such as lug work. For those spots I just use a soft screw driver blade (a small one) to chip and scrape away the paint. A final sanding with fine emery cloth and the task is complete. Primer immediately. And, as a safety precaution, were eye and respirator protection. Debris can fly off of the rotating wheel and suspended particulate will be easily breathed in so wear a dust mask. For more detail on how I go about removing paint, have a look at this article on paint removal...
http://www.mytenspeeds.com/My_TenSpe...troduction.htm
Hope this is a help.