I bought a 55 gal polyethylene drum to use as part of a swim platform. It has two screw in plugs. One is poly and fits tightly. The other is steel, and the thread doesn't even resemble the thread on the opening it was in; though it is a very snug fit. I doubt I will get a good seal on it. Since I will never open it, I would like to glue it in. I know nothing sticks well to poly, but I am thinking JB Weld will fill in the thread spaces, and lock the two together. But maybe silicone caulk would be a better bet.
Any thoughts on the best way to seal the metal plug in? It is about 3" diameter and 1/2" of thread.
I bought it at an auction as part of a large lot with all kinds of other good stuff for a dollar, and immediately sold stuff out of the lot for $3, so it was a good buy even with the wrong plug.