Reinforcing element for a closed section and manufacturing method

A method of making a reinforcing element configured to be received within a longitudinally extending cavity defined by a structure, the method comprising:

• providing a base portion having a bonding material applied thereon;
• and securing a member to the base portion in manner such that the member is moveable with respect to the base portion, the member configured to selectively extend away from and be aligned in a longitudinal direction with the base portion when the reinforcing element is received within the cavity such that the reinforcing element defines a first length in the longitudinal direction when the member is in a first position with respect to the base portion, and a second length in the longitudinal direction when the member is in a second position extending away from and be aligned in the longitudinal direction with the base portion, the second length being greater than the first length,
• wherein the member includes an extrusion plate received within a central passage of the base portion, the extrusion plate configured to force an adhesive through the central passage, where said adhesive was pre-deposited in said central passage,
• wherein the bonding material includes a structural adhesive, and
• wherein the structural adhesive is non-expandable.