I found (on this site) the DIY instructions for making the lauter/mash tun out of a cooler. I made one with a ten gallon rubbermaid round as a mater of fact mine even has the home depot logo on the front.
The key is the good fello that posted it also put up a parts list that has all of the part numbers and everything. He even has photos of the parts in the order he put them together.
Here is a frustration saving heads up. When you buy that stainlest steel braided line make sure it IS stainless and not the silver plastic stuff. Look real close don't be fooled!
I am very pleased with the way my mashtun works even with one third of the grain bill on my brew being wheat. There was absolutely NO clogging.
One other heads up. When I started I poured about a gallon of 175 degre water in, then dumped in my crush, then poured four gallons of 175* on top of it and started stiring. within about 20 seconds I started hearing this scary cracking sound. I thought that the inside of my newly made mashtun was cracking.
However the outside was fine as was the inner liner. The big cracky noise had to have been what ever spray foam instalation they use inside the walls. After the brew day was over and I was cleaning up my equipment I gave it a three point inspection and all was fine.
Okay I searched out the thread http://www.homebrewtalk.com//showthread.php?t=23008
The only thing I did diferent was if you look at the picture those three big washers are bigger then the ones I bought. If you look at the spicket on the cooler you see that the base is round and is recessed into the side of the cooler. I bought washeres that fit into the recessed base spot. I used a reamer to make the holes (of the washers) just a smidge bigger as I couldn't get them over the nipple threads without forcing them.
I think I have a total of 71.00 dollars invested into my mashtun. The cost at your local HD my be different. I hope this helps you get your whole grain brewing off the ground. It is easy and fun.
I watched a video called "Easy Home Brew-How to brew beer with all grain". Kind of informitive, but I get more info from the book "How to Brew" by John J. Palmer copyright 2006. This book is loaded with in depth info which is good, but it also has alot of "Quick start" stuff that gets you brewing now and you can read the rest while you nurse a tasty brew.
Good Luck and Good brewing! - Robar