I just bought one of these bulkhead fittings from Northern Brewer for my Coleman Xtreme, and I have it attached, and it's sturdy, but I do have one nagging concern about it. Does the brass locknut on the outside of the cooler need to be completely tightened against the wall of the cooler? It's really tight, but the instructions say to tighten until the nut "bottoms out", which I assume means to the cooler wall. It seems to me that the big o-ring is going to get damaged if I do this. And, yes, I followed the instructions for tightening it from the inside to avoid damaging the ring.
I'm probably fretting over nothing, but I figured since I have an army of experts here, I'd be a fool not to ask, just to make sure.