The period during which urethane remains workable after extrusion is called

• A. Working time
• B. Gel time
• C. Cure time
• D. Shelf life

Answer: (B)

Gel time is the period during which urethane remains workable after extrusion. It marks the transition from a fluid, moldable mix to a gel-like state where it starts to lose flow and hold its shape. During gel time you can still position and mold the bead, but once it reaches the gel stage, you’re limited in how much it can be moved. After gel, the material continues curing toward its final strength, which is governed by the cure time. Shelf life is simply how long the material can be stored before use, and working time is a broader term sometimes used for the initial window to work with the material; however, the specific phase that describes the drop in flow after extrusion is gel time.