I haven't really use the stuff. The few times I have it simply didn't hold up. I did have one come in this year where someone had use it to patch the fuel bowl rim of a Walbro carburetor on a push mower. It had failed and clogged the jets. It simply crumbling off in small pieces and when I tested its hold it all fell off.
I ended up replacing the whole carburetor with a reclaimed unit from a new mower that another customer ran without ever putting motor oil it. There was a large in the side of that engine for some reason.