Removing Silicon from an old sump?

[Wy Renegade]

Rebuilding an old sump that failed (acrylic walls in a glass tank). Have removed all the acrylic pieces and scraped most of the silicon off the walls with a razor blade. However, have silicon still where it is attached to the silicon that seals the tank. Anyone have any suggestions for removing the baffle silicon from the tank silicon without breaking the tank seal?

 

[Troylee]

lots of new razor blades and acetone will do the trick....sometimes steel wool works also..