Solvents for removing very old masking tape from front panels?

On Sat, 13 Jul 2013, David Griffith wrote: Yikes. The youtube video bothers me in that the acrylic sheet was already under tremendous stress from the bungee cord before anything was done to it though. Acrylic (unlike polycarbonate) is very brittle. Curved the way it was in the video, it was likely already growing microfractures in the surface, and probably would have eventually broken even just sitting there with the bungee cord on it. While they look similar, there is a chemical difference between polycarbonate (lexan) and acrylic [or more appropriately, poly(methyl methacrylate), aka PMMA] (lucite, perspex, plexiglas, etc). I've had no issues cleaning polycarbonate with isopropyl, and manufacturers specifically recommend alcohols such as isopropyl, ethanol, etc for cleaning. On the other hand, ammonia based cleaners (such as Windex) /will/ damage polycarbonate (and PC-ABS plastic blends), often causing stress fractures later. This /does/ help explain some of the cracked and crazed modular connectors [http://en.wikipedia.org/wiki/Modular_connector] I've seen over the years that had been cleaned with alcohols though. While the standards call for polycarbonate, those plugs must have been molded with less expensive acrylic instead of polycarbonate. This is something to keep in mind for later too since companies keep trying to phase out polycarbonate due to the fears over the Bisphenol A content. For that fact, I should see about taking microphotographs of some of those plugs that are still in my scrap bin... I guess this is yet another reason for me to avoid acrylic and stick with time-tested polycarbonate and also always check chemical compatibility.