Definition
The period during a glued joint's assembly that begins when the parts being bonded are brought together (closed) under pressure and ends when the adhesive has fully cured. It is the time the adhesive spends working between the mated surfaces while clamped or pressed.
Plain English
The amount of time the glued parts are held tightly together while the glue sets. It starts the moment you press the parts together and ends when the glue has finished hardening.
Context Anchor
Seen in aircraft wood, fabric, and composite repair instructions where parts are joined with adhesive.
Derivation
"Closed" here means the joint is shut — the two glued surfaces have been pressed together. So "closed assembly time" is simply the time the assembly spends in that closed, clamped state. The matching term is "open assembly time," which is the time before the parts are joined.
Why Pilots Care
Following the correct window produces reliable bonds; exceeding it creates weak joints that can fail in flight.
Intuition Check
Do not read this as simply the total time needed to assemble something. Here, it means one specific interval: after the parts touch, but before pressure is applied.
Example Sentence 1
The technician left the wing rib clamped overnight to satisfy the adhesive's closed assembly time.
Example Sentence 2
Exceeding the manufacturer's stated closed assembly time forced the repair team to remove the parts and start over.