Seam sealer is stuck to itself

I buy REI seam sealer in a plastic bottle. As long as it is factory-sealed, it has a good shelf life. Once I open it and start using it, some air will remain the bottle. That air starts curing the top of the liquid in the bottle. After a year or two, it will be virtually unusable.

So, when I buy a new bottle of it, I tend to use the whole bottle within a short period of time while it is perfect.

–B.G.–

I'd give up on the original spout and punch on whole in the body or snip a corner to access fresh sealant.

Is the bottom end of the tube still soft? If so, puncture that end of the tube to see if it works. If it's silicone-based sealer, it undoubtedly is completely solidified. I've never had the stuff, once open, last more than 2 years. I do have a tiny tube of Seam Grip (not silicone-based) a little over 2 years old which is completely plugged, but the bottom end is still soft. I haven't tried it to see if the sealer is still usable, though.

IMHO, 5 years is an awfully long time to expect most substances to last once they have been opened.