Open time
Open time is the window after applying an adhesive during which the surfaces must be joined for a good bond. Applying after open time yields a weak bond.
Ask Chalkline about this →Open time is the period after an adhesive is applied to a surface during which the surfaces must be brought together for a proper bond to form. Once the open time has elapsed, the adhesive has skinned or partially cured to the point where pressing two surfaces together produces a bond of dried adhesive film to dried adhesive film rather than adhesive to substrate; the result is a weak joint that will fail under service loads.
Open time varies by adhesive type, temperature, and humidity. Polyurethane and MS polymer adhesives skin faster in hot or dry conditions; PVA-based adhesives extend slightly in cool, humid conditions. In practice, open time is 5 to 30 minutes for most construction adhesives. Always check the product technical data sheet for the specific open time at the ambient conditions on the day.
Also known as: working time, assembly time
Category: Adhesive application terms
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Last updated: 2026-05-09. Verified: 2026-05-09. Quarterly review for currency.