Finally put together a solution for the propane line feeding from the back of my Camp Chef oven. Previously, I would have to feed the hose from the back of the oven around to the front, then feed it around the galley opening to attach to the tank...no big deal except I would have to detach the hose from the tank every night so I could close the hatch to secure the galley from nocturnal critter invasion.
Here's what I did...
Bolstered my courage with a strong beer

, borrowed a 2-1/8" hole saw from my neighbor because I couldn't find my 2" hole saw

, measured once and then once again, then drilled the hole. (Note to self: next time drill a small pilot hole first to make sure I have the right location.) Sealed the raw edges with Helmsman Spar Urethane, and sealed the edge of the plug as well (I use the plug and a scrap of cheapo shelf liner to secure the hole when the teardrop is stored).

Next, I attached a rubber boot (that I found in the myriad of parts I bought for the build but hadn't used) to the underside using butyl tape and stainless steel screws.

Fed the 5' hose that's always attached to the back of the stove/oven through the exit portal.

Now I can attach the hose to the 5# tank, leave it attached the whole time I'm camping AND have the galley secured at night.

A friend is making a simple holder for the tongue where I can store, transport and easily remove the 5# cylinder for camping.
