If you need a tough epoxy that is nearly as strong as metal, JB Weld is the only way to go.  This particular one is NOT a quick set epoxy - takes approximately 6 hours to start firming up, so you have plenty of working time.  Consistency is a little runny, so you have to dam it with tape to keep it from running into places you don't want it while it sets up.  I have used JB Weld to repair "impossible" breaks and have always had good results.  You have to mix both ingredients equally to get it to start - so stores well until you need it.