I made a mash tun from a 37L (that's 9.5Gal) cooler. (25cm H, 45cm L, 33cm W) I used 1/2 inch pipe with holes drilled in it to allow the wort to drain. I made a square pattern with 2 cross pipes. I was lucky and the cooler had a drain that fit the tubing perfectly so I didn't have to drill any...