Originally Posted by
Bill Kapaun
They don't "dry out" nearly as fast if you squeeze the air out before replacing the cap.
I've had 2 never opened tubes of the REMA cement dry out despite being factory sealed - admittedly, that was during a more than a decade long hiatus in my cycling. So I had like 10-12 perfectly good patches and no glue to use them. The $3 Xtra Seal 1 ounce tube at O'Reilly solved the problem.