Here's how you make your own hot tank in the backyard of your mom's house. First, you request MSDS sheets from the companies which sell hot tank solutions. From these, you can decipher what the active chemicals are. In this case, it basically turned out that hot tank solution is more or less pure lye, which consists of sodium hydroxide and sodium bicarbonate. Anyway, then you call up an industrial supply company and buy about 50 pounds of it (about an 800 engine supply) for about 40 bucks. Turns out, they use it for food preparation(?), so anyone off the street can buy it. Then you go get a 55 gallon drum and a ni-chrome heating element which wraps around the bottom of it to heat the contents. Then you mix about a cup of the chemicals with water. It also helps if you stir it all up with your mom's broomstick handle. Then you unplug your mom's 220 volt clothes dryer so you can plug in the hot tank. Then you lower engine blocks into it with your engine hoist, and VOILA! The next day your parts are as clean as new. However your mom may be slightly pissed that her backyard has been turned into an EPA hazard zone, and that she can no longer do any laundry.