Iv used JB weld for many things, some work well, but others didn't fare so well. Any which way, its all fun to learn what works and what does not.
My latest was sealing a 90 degree elbow in an oil pan to us e to relocate the drain for the boat.
This worked but was very slow to drain.
I have the engine out again as a new engine problem came up, and found the JB weld really held well.
In fact it held so well when I wanted to remove the elbow to drill and place a larger pipe, I broke the elbow off instead of breaking the JB weld trying to get it out.
I have also used JB weld to rebuild impeller pump surfaces with a lot of luck.
I have on occasion used JB weld to recondition badly corroded carbs.
I have learned that it works well in iron carbs, but in aluminum carbs in extreme temp environments, the JB weld will crumble as things contract.. I found this unpleasant surprise one spring after failing to be able to start an ATV I did this with.
Ahh well its all fun, anything I really need done right, I wont leave it to chance.