So I'm topping-off the A/C on this Accord.

But suppose it doesn't need a whole 12oz. can of that stuff. The can's top is pierced and if I unscrew it from the hoses, it'll spew nastiness all over the place.

Yes, it smells like bad farts, or baked, overripe garbage, but I personally don't care. But I keep seeing people cautioning about venting that crap into the environment (some kind of R-12 environmental holdover I guess), and so WTF am I supposed to do with 1/2 can of that stuff on the end of my hoses?

 

Plan A: There's a 16 yr old kid in your neighborhood. You take any remaining Freon,
can still attached to the hose and valve along with $20, and ask the neighborhood kid to take care of it for you.
Then relax...

Plan B: leave it in your garage where it will slowly leak out over the next 6 months and you can then toss the can away,
deciding whether to keep the valve and hose - or not.

 

didn't tell us why you were "topping off" the A/C system...and did it fix your issue?

 

It did... for about a week. Got nice and cold. But now, its back to its same old tricks.

 

You can put the can w/ tap in a freezer and it will keep indefinitely. Boil-off rate at 15-20F is very low

In garage the gas will leak past the tap in a few weeks/months.

good luck