Kapton is a very good electrical insulator. It is made into a tape that is good enough for aerospace and satellite applications. Its characteristics include:
- High temperature stability - you can solder on it (800 degrees F) and not damage or distort it! Hopefully your loco will not be that hot inside. This also relates to the adhesive - it still sticks after exposure to such temperatures!
- Thin - a good insulation for the voltages found in DCC can be had with a tape only 0.001 inches (0,02 mm) thick!
- It does not have a lot of shear (tearing) or punch-through strength. Don't expect it to insulate a solder joint with the jagged end of a wire sticking out - use shrink tubing!