So Santa brought me a bunch of AG equipment and I plan on trying out my first AG batch on Saturday. I've got a 5 gallon picnic cooler for my mash/lauter tun, and I've seen pics of those with thermometers mounted to them (the sharp 'business end' inside with the circular gauge visible on the outside). If i do this, will it require any sort of sealant or washer? Could I just drill a small hole in the cooler and ram it in there? For experienced AGers, is it worth it to have this so you don't have to take the lid off to take the temp?