One of these days, I'm going to get around to building my mash tun. I bought a round cooler, but have also acquired some larger rectangular coolers. These are used coolers of indeterminate age. Coleman Polylite 48, IIRC.
Any concerns using an older cooler? One of them has some stains on the inside, but I can bleach the bejesus out of it.
Also got a newer cooler that has no drain. I could bore through with a spade bit, but the other coolers seem ideal as long as there's no concerns about the older plastic or anything like that.