Cold Crashing when it is warm out?

I am looking to cold crash in a week or 2. During the winter I usually just throw my carboy out in the garage, now The problem is that the temp is starting to fluctuate from 30's to 60's in the course of a day.
unless over night in the 40's is adequate?

I considered using my chest freezer for a few hours, but I have no place to store the food, not to mention it is not really stable.

I was thinking of using a big plastic tub or cooler and making an ice bath to drop the temp.
I would do this for about 24 hours.

I will encounter the same issue during the summer.
for the record I am not looking to buy anything or build anything.

Anyone have any Inexpensive, simple DIY ideas?

 

Big Rubbermaid tub full of (mostly ice) ice water might work, trouble is you'd have to change the ice several times.

 

Without buying or building anything, you're kind of in a jam. A tub of water with ice is your only bet. Be very prepared to watch that temp hourly and have ice on hand to keep it at the right temp. Or don't cold crash.

 

I've used rubbermaids the way Testudoed describes. if you go that route use frozen 20oz or 2 liter bottles and keep rotating them into the tub.

I ran into the same problem keeping a couple 1/6 barrel kegs cold just a few weeks ago (just before I built a keezer) and I ended up tossing them into a big cooler with some of the snow leftovers that hadn't melted away. The cooler, even wide open, holds a temp far better than a rubbermaid, question is would your carboy fit?