So I had the idea a while back to build an external firebox for my kettle. I had considered just doing a mailbox mod, but where is the fun in not going overboard? It is made of 3/16 hrs and the chamber is an 18" cube. It will come in just under the grate on the opposite side of the handle. I will be cutting the hole in the side of the Weber this week and I'll update with more pictures if anyone is interested. Thinking of leaving this as a modular firebox that I can move around and hook up to different cook chambers I am planning to build in the future. It is currently getting seasoned with some peanut oil as it is what I happened to have on hand.