Plastic repair kit will do the trick. I use Q-bond -> http://www.qbond.net/pg_1/pg_1.htm

You will need to make sure the epoxy that you already put on is not blocking the air passageways. Depending on how it's broken, you may need another hand to hold it together. Sprinkle on the plastic powder around the break, a few drops of the solvent, wait a bit, then turn it over and do the other side.

I have ocd, so I'd probably hold it together and use a small die grinder attachment on the dremel to put a u shape channel around the break, this will allow you to get an almost invisible repair, and it will give you a larger bonded surface.

If it's a standard black X piece, it's marginal whether the cost of the repair kit is worth it, although you will have plenty left to repair fairing cracks etc. If it's a HRC piece ie Red, then definately worth repairing.