I had ordered some Loctite 565, which along with Loctite 577 and 272 appears to be a good product for securing fittings into the cooler. It's due to come in 1/5 - blowing this whole week off work. I remembered that I had some polysulfide in a semkit (a proseal product) and put that on the threads. It's definitely good for oils/fuels and the temperature range. We'll see if it makes a good seal. Downside is it's potentially much more permanent than the Loctite product if there's a leak.
