Hole in a pipe of the Hartford Loop.

Check out the Blue Monster Big Compression tape video on this thread:
http://forum.heatinghelp.com/discussion/comment/1415816#Comment_1415816

Charlie from wmass said:

Jb weld. The tape will melt. Or find a local pipe welder.

Specs say effective up to 150 PSI and 500*F. It won't melt on a residential steam system.

For what it's worth, the Blue Monster stretchy tape has held on a pinhole in a 4" main for going on five months now, 2# of dry steam on it whenever the temp is below 50*--the boiler doesn't cycle, it's very possible it had live steam applied for two months continuously.

I really like that stuff. For repairs are least.