Seam Grip WP, Aquaseal FD, and Aquaseal SR are moisture-cure adhesives. As soon as you open the tube and expose the adhesive to the moisture in the air, the countdown begins. Unfortunately, you are unable to stop the curing process, but you can slow it down by storing the adhesive in a dry environment like your freezer. We recommend storing our adhesives as follows.
Advance the contents to the tube neck to remove any air that may be trapped in the tube. Next wipe the tube threads clean to prevent the cap from sticking. Cap tightly. Place the adhesive in a plastic zip-lock bag. Store the adhesive in a dry environment like your freezer. When ready to use, run the tube under warm water for about a minute.
While this will not stop the adhesive from curing, it will help slow things down.
We give an unopened tube of adhesive a four-year shelf life. The "born-on" date will be crimped into the bottom of the tube. The adhesive is typically good for four years past that date.