I too like a super sucker. I am building a new smithy and plan to use Torbjorn Ahman’s design he uses 12” stick of pipe (stainless I think). On the inside of the pipe he welded a “shelf” to catch a handle of a rod. The rod has another guide near the top of a piece of pipe to fit the rod 1/2” is what i plan to use. On top of the rod he welded a “disk” like used in farming. As mentioned the hood rarely get so hot as to not be able to touch, he pushes up the rod/disk and seats it on ledge in bottom of pipe to open flue/stack and lets it down to seal weather out. It uses common inexpensive metal with only a little fabrication 3/4 welds and your open for business. It fits my juckyard stock and my opinion of functionality over looks. Imho. You can see on his youtube page. Be safe and good luck