Glue Clamp Time Calculator
A clean glue-up depends on respecting three times from your adhesive data sheet: open time to assemble before the glue skins over, clamp time before you can unclamp, and full-cure time before the joint takes load. This calculator adds those times to a planned start to schedule each stage, so you know the latest moment to finish assembly, when clamps come off, and when the joint is safe to machine. The times are yours to enter, since they vary by product, temperature, and humidity.
Glue-up schedule formula
finish assembly within = open time (from glue spread)
unclamp after = clamp time (from clamping)
safe to load after = full-cure time (from clamping)
Each stage runs from when you spread the glue and clamp. The calculator simply restates your data-sheet times as a clear sequence so nothing is unclamped or stressed too early.
Worked example
A PVA glue has 5 minutes open time, 30 minutes clamp time, and 24 hours full cure. You must complete assembly within 5.00 minutes of spreading glue, can unclamp after 30.00 minutes, and should wait 24.00 hours before machining or loading the joint. In a cold shop, increase all three.
Glue clamp time: frequently asked questions
What is clamp time versus cure time?
Clamp time (or assembly time) is how long the joint must stay clamped before it can be handled, often well under an hour for PVA glues. Full-cure time is how long until the joint reaches full strength, often 24 hours. Open time, or working time, is how long you have to spread glue and assemble before it skins over. These values come from the adhesive data sheet.
How does this calculator help?
Enter the open time, clamp time, and full-cure time for your adhesive. The calculator adds them to a planned start time so you can see when assembly must be finished, when you can unclamp, and when the joint is safe to machine or stress. It schedules your glue-up rather than guessing the chemistry.
Where do I get the times?
From the technical data sheet or label of your specific glue. Times vary widely by adhesive type, temperature, humidity, and wood species, so there is no single correct figure. This calculator uses the values you enter rather than assuming a product.
Can I unclamp before full cure?
Usually yes. Most PVA glues let you remove clamps after the clamp time, but the joint is not at full strength until cured. Avoid heavy machining or load on the joint until the full-cure time has passed. Cold temperatures lengthen all of these times.
Sources and method
- The schedule restates the adhesive's own open, clamp, and cure times; it invents no figure. Enter the values from your product's technical data sheet.
- USDA Forest Service Forest Products Laboratory: Wood adhesives and bonding research.
Reviewed by the CalculatorHub team, edited by James Graham, 19 June 2026. See our methodology.