it wasn't the igloo cooler, it is the 48 qt rectangular coleman cooler. It's the part that fits partially inside the hole on the inside of the cooler. Yea I figured that any food grade o-ring or washer would probably do the trick in terms of sealing any potential leaks. Looking to do my first batch in the coming days once I get the mash tun together.
I bought a half inch stainless braided tube thingy (yet to cut and remove hose) ... will half inch work well, or do I need to go bigger?