Most fabricators have a shelf (or shelves) of partially used glue tubes of various vintages. How do you know what is safe to use and what you should just dispose of and replace?
While there is some variation from manufacturer to manufacturer, old solid surface adhesive should always be tested before use if you suspect it is near or past its shelf life.
With Seam-it adhesives, you can expect a shelf life of 12 months from the date of production. We’d like to give longer than a 1-year shelf life but having no control over storage conditions limits us. If stored properly (room temperature or below) our adhesive will perform within reasonable cure speeds for 18 months – 2 years.
The main thing to consider if you have dated solid surface adhesives is that they do not just stop working one day. The catalyst component gets weaker over time and high-temperature storage accelerates the process. Therefore, a solid surface adhesive that is one month old stored at 72 degrees will cure at say 30 minutes. The same cartridge 12 months later, may take 38 minutes- 18 months, 43 minutes etc, etc. At some point, the catalyst becomes too weak to fully cure. If you were to store the same glue at 100 degrees the degradation of the catalyst would occur faster (might take 45 minutes at 6 months). Worst case scenario, a couple of hours on the dash of the install truck in Florida during the summer will render it useless.
If you have old solid surface glue, run some beads and time the cure. For Seam-it, we recommend a rock hard cure be achieved within 30-45 minutes for the adhesive to be considered within spec.
Finally, to dispose of outdated adhesives properly, purge the cartridges into a container, mix in a ventilated area or out of doors, and leave to harden. Caution, a large mass of adhesive will generate a great deal of heat when curing.
For more information about countertop surfacing adhesive, visit www.GlueWarehouse.com
About the Author: Chad Thomas has been in the adhesive industry for nearly 10 years, previously working for a major manufacturer and now as a partner at Gluewarehouse. Expertise includes color matching, bonding theory and glue applications in the surfacing industry. Contact chad at firstname.lastname@example.org or call 877-595-4583