Heat the blue Scotch tape with a hair dryer. Direct hot air onto the blue painter’s tape for around 15 seconds to soften the adhesive.
Pick the edge of the blue tape with your fingernail. Pull the loosened edge and peel entire blue strip off the fiberglass.
Rub the remaining adhesive with your finger. Roll the sticky residue into a wad, and then pull the adhesive wad off the fiberglass.
Moisten a cloth sparingly with acetone-based nail polish remover if unyielding adhesive remains. Gently rub the adhesive with the solvent until the sticky substance comes off the fiberglass.
Saturate another cloth with water. Wipe the solvent and adhesive fragments off the fiberglass surface.
Wipe the fiberglass with paper towels. Absorb all moisture from the fiberglass.