I have had a leak on my Stromberg that I have been trying to get stopped for some time now. It leaked at the site plug. Or so I thought. I tried tightening it. I tried using all sorts of different sealants and even . I was about to go the route of a thread locker or a different carb but then looked closer. Midline of the sight plug is a casting seam. As I looked more closely I watched the leak with a flashlight and after wiping the area with a rag and seeing the slow flash of the gasoline as it creeped and expanded it dawned on me that maybe there was a hairline crack at that casting line. So I tried a product used for fuel tank repair. An epoxy. I mixed a small bit of it up about the size of a copper BB. Then smeared it against the carb pressing it into the seam where I thought the crack might be and voila it stopped almost immediately! Thought I would share.
Truly sorry didn't really think it was that "technical".....I still don't really get the criteria and should probably re-acquaint myself with them. Even if I circled the repair you would not see it. Hell I cannot even say that I could see the crack. It was a hunch. The repair is on the right side of the vertical seam below the sight plug screw. The amount that I smeared in cannot even be seen but the results were awesome. I just wanted to show the casting line in case someone might be experiencing and chasing the same mystery leak that I have been.