For a good comparison of different types of home made mash tuns, get the 1995 "Great Grain Issue" of [/I] Zymurgy[/I]. For $20 you can get a 5 gallon water cooler, or $40 for a ten gallon one. $20 for a Phil's Phalse Bottom, or about $10 more for SS. Add a sparge arm and you'll get higher efficiency than the chest cooler.