Yes there are better products for this job than JB weld, but JB weld is
still pretty good. After all it has been patched before with it and I gather
it lasted for a long time. Also I gather that you are looking for something
temporary until you can get it welded. JB weld would be my choice. Its
cheap, readily available and will probably do the job you want done. We used
it at work to patch a similar crack in an 80 KW engine/generator set. The
patch was replaced twice over a period of seven years then the e/g was
replaced, at this time the crack was poperly repaired , the old e/g placed
an a trailer and is still being used as a portable unit.