Does the t-shirt method work for plastic buckets?

Yes, it does, just make sure you use a shirt you don't plan on wearing again, the handle will rust and leave stains on it, and it will also stretch it out kind of funny.

 

I personally use an old towel vs. a T-shirt over my plastic bucket. My thought process is that a towel holds/wicks more water than a (thin) T-shirt.

Cheers!

 

The plastic won't conduct as well as glass.
You're better off using a cool-water bath regardless of what you ferment in.

 

i have used it with some success with a plastic bucket. you could always make a swamp cooler and swap out some 2-L water bottles of ice twice a day. do you have a basement? putting it down there will help also.

good luck

 

Something that I posted yesterday which may be helpful to the OP:

So, I brewed a Wit yesterday. My homebrewing area (utility room in my half basement) is a bit too warm now (ambient about 72-73°F). My preference is to ferment my Wit beers around 70°F (although 72°F would be OK). So, since fermentation is an exothermic reaction (it produces heat) I need to ‘manage’ the fermentation temperature. Right now I am able to do that by simply placing my bucket on the basement floor; the basement floor operates like a heat sink drawing the ‘excess’ heat away. I will just use the ‘floor method’ unless the fermentation temperature exceeds 72°F. If that occurs I will place my fermenter in a shallow Rubbermaid pan (about 5 inches tall) and put water in the pan. The presence of water increases the heat sink effect by cooling a couple more degrees. If I should need even more cooling I will place a towel (or a T-shirt) around the bucket for evaporative cooling. If even more cooling is needed I add a fan to the mix.

Cheers!

 

I've been taking used gallon jugs of water, filling them back up, then freezing them, and placing them up against my plastic fermenter. Seems to do a decent enough job.

 

I use a large tupperware bin and fill it half full of water. Frozen water jugs/ 2 liters are key to getting a low ambient temp for fermentation. Otherwise, you should probably stick to wheats and saisons this time of year.