Actually I purchase the largest bottles of CA I can.

It doesn't go bad, and I have no cap on it!

How?

Those "capillary" tips which places like Tower sells.

These things are WONDERFUL.

You open the bottle and place one on the top of the bottle's plastic tip.

The CA will flow through the capillary, but it will not dry out as the opening is so small that it prevents hardening and evaporation.

I've had CA bottles like this for many months w/o a single problem.

If I gum up the capilllary with balsa, etc. I just cut a tiny sliver off the tip.

Very nice.