Originally Posted by david_ski
I had a similar leak in my muffler. I used fiberglass and resin on exterior. I will post a picture tomorrow. I actually used a mirror and inspected the inside and found a fairly large crack at the 45deg angle on the inlet side. Unable to glass the inside, the exterior fiberglass and resin worked just fine. Much less in cost than a new replacement muffler.
This was deff the way to go , I glassed them up and everything is good so far ..!