Acetone -- OK To Use It Outside?

From what I've read, I don't see a problem with the sun or temps (excluding above autoignition theshold). Some that I've done recently needed a LOT of attention so they stayed in nearly 48 hours (using new acetone halfway through). The only concern I would have is the acetone evaporating, which it does very quickly! I've been using 8oz Ball wide-mouth canning jars. They work well for me, the only problem being the acetone will eat away at the lid coating even after a short time, but they're easily replaceable. Keeping it sealed will prevent your coins from being left dry in a jar on the porch where moisture can attack.

I think that having plenty of ventilation (such as being outside) when using acetone sounds like a good idea.

Are we talking about a large number of coins here, and a large volume of acetone? While ventilation is a good thing, you may want to consider staying comfortably indoors with more control over your environment. Stuff happens: a breeze could blow towels away, coins could be dropped between deck slats... Anyway, I would do this one coin at a time to avoid coin-on-coin contact. I use a wee dram of acetone in a shot glass and wooden chop sticks for coin manipulation. Start with the relatively cleaner coins and work your way to the dirtier ones, then change the acetone and repeat as often as necessary. Keep vapors to a minimum by disposing the dirty acetone in a lidded jar, which can be taken outside later and opened. Avoid open flames.

Thanks, everybody! My mom, who comes over to my place frequently, is acutely sensitive to chemicals, so outdoors really is the best solution. My deck is mostly private; the only folks who have a good view of it are the two older ladies who live next door, and if I do it right, all they'd see is me coming and going, and a couple teacups sitting out there. They might smell acetone but I doubt they'd understand what was going on.

The one coin at a time advice is great. I see it working this way: I'd take a coin out, slip it in the acetone, give it several minutes, bring it back out, and slip it in a cup of fresh water for a rinse, then take it back inside to air dry indoors.

Most of these coins probably came out of the till at my grandpa's gas station. They are generally well circulated and many were cleaned, not to mention unless they are in holders (only a few that look store bought are), they've been stored for decades in direct contact with those notebook pages. There are no key dates (unless you count a couple 1950D nickels). So the value is more sentimental than monetary. I'd like to preserve them just because they were my grandpa's.

Any further advice is welcome. I won't be doing this for at least a few days.

My chopstick skills are good because I eat a lot of take-out. I haven't had much luck using plastic tweezers with acetone... either the plastic or dye inside dissolves. You may be able to find some Teflon coated metal tweezers somewhere; those should be okay - the PVC coated tweezers are to be avoided!

skip the water after acetone rinse. rinse with clean acetone instead.

Outside is the best place to use acetone. Just make sure that flame isn't anywhere near the stuff!

The sun won't cause a problem and the only effect from the cold would be the acetone will evaporate just a little slower.