Really stoned right now, ill try my best..ill come back tomorrow to fix it up..CHECK OUT THE PIC BELOW FIRST to get a better understanding of whats going on. Below is a link to the one in the pic.
If you want to avoid 90% of the hassle below purchase this..."peltier thermo electric
cooler module + heat sink" $34
http://www.adafruit.com/product/1335 . They also sell them on ebay for $16, Go to ebay and type in "Thermoelectric peltier refrideration cooling system kit fan" once you have that thermo electric cooler module then all you need is the rod from lowes or where ever. Make sure your rod is perfectly flat, just super glue the rod to the plate. You will also need an apapter "12v dc 5amp" . You could possibly avoid the rod all together if you think you have the skills to attach this thermo electric module to a lowes 5 gallon cooler. However the rod would make it easier to install on the lowes cooler since all you would have to do is drill a hole to slip the rod through.
Items you will need:
1. large cpu heat sink====, i used an oem core i7 cpu heat sink, ebay $8 to 11, The intel one has a round heatsink, it is best to get a cpu heat sink that is square to match the peltier plate.
2. thermoelectric peltier plate ====$2.00 preferably 60 watt version, they go up to 500 watts, 60 watts is all you need for a dwc cooler. Mine is hooked up to a 50 watt adapter to a 60 watt peltier plate.
3. 12v dc 5amp power adapter
4. 1 inch diameter round rod==== but it all depends on the size of your pertier plate, my iron rod is a little smaller than the peltier plate but it still works just as good as the iceprobe i bought, it would be best to use aluminum or copper since those metals corrode slowly..i used an iron i bought at lowes so i just painted it prevent it from rusting. VERY IMPORTANT..the end of the rod must be perfectly flat.
5. super glue
Some people use a flat piece of copper on each side of the peltier plate to cover the whole perltier plate, i havent done this and it still works. Pelteir plates are cheap so i didnt care if one failed.
super glue the peltier place on top of the heat sink then super glue the perfectly flat rod onto the other side of the peltier plate. Connect the fan wires and peltier plate wires together...youre finished. If the wrong side of the iceprobe gets cold switch the wires around.
Heatsink to peltier plate to rod, it looks like a cheap piece of electronics from the 80s but it works, using it right now, been working for six months.
Added..people use super glue as a thermal paste because it performs better than the thermal paste but it is permanent once you have it together.