Blow-molded plastic structures

A method of manufacturing a blow-molded plastic structure, the method comprising:

• placing a tool in a portion of a mold for blow-molding a plastic structure;
• forming a parison of molten plastic;
• disposing the parison of molten plastic in the mold;
• closing the mold around the parison of molten plastic;
• inflating the parison;
• and
• creating an inwardly extending portion with an undercut with the tool.

A tool used to create an undercut in a blow-molded plastic structure constructed using a blow-molded process, the tool comprising:

• a base;
• a first guide at least partially disposed in the base;
• a second guide at least partially disposed in the base;
• a first finger at least partially disposed in the first guide, the first finger being movable relative to the base between a molding position and a release position, the first finger including an elongated body and an outwardly extending portion;
• and
• a second finger at least partially disposed in the second guide, the second finger being movable relative to the base between a molding position and a release position, the second finger including an elongated body and an outwardly extending portion.