Brian Lawson fired this volley in
:

I can't recall how they store/stock
the stuff in the bulk quantities they use, but even in a closed bottle
they put my few ounces in its GONE by magic within a month, long
before the day I've ever wanted to use it.


Brian, there's a trick to keeping methylene or ethylene chloride. It
does have a very high vapor pressure, and will even evaporated out of the
bottle if kept in your freezer.

I've kept a gallon in my unconditioned barn for over five years, and have
lost only about a quart to evaporation in that time. Here's the trick:

I bought a five gallon blue gas can (to visually distinguish it from my
red gas and yellow diesel cans). Put the methylene chloride in, not more
than half full. Gently fill the container to near the top with clean
water.

Surprisingly, methylene chloride is quite a bit more dense than water,
and almost totally immiscible with it. The methylene chloride stays on
the bottom, and water "cap" exerts enough hydraulic pressure and enough
passivation to the interface to almost totally prevent evaporation.

When I wish to dispense it, I merely invert the can so the air bleed cap
is bottom-most, then give it a gentle shake to float any water beads out
of the cap recess. Crack the cap, and the clean methylene chloride flows
out (under pressure, no less) into my working vessel.

Your can will swell in warm weather. It will collapse in the cold if you
don't replenish the used amounts with more water.

LLoyd