I have to vote with the previous post on epoxy.
The real trick is to get it to spread evenly. Best method I have found is to apply the epoxy on one side and used compressed air to blow it through the crack/split and impossible to reach areas, wipe off all the excess. Shoot the air the opposite direction and repeat until no more excess appears, pushing air both directions. Then use surgical tubing that you would use for sling shots to wrap around the cracked area, increasing tension with each wrap.
Some tubing may stick when removed, but this can be gently scraped off with a sharp knife.
The real trick is to get it to spread evenly. Best method I have found is to apply the epoxy on one side and used compressed air to blow it through the crack/split and impossible to reach areas, wipe off all the excess. Shoot the air the opposite direction and repeat until no more excess appears, pushing air both directions. Then use surgical tubing that you would use for sling shots to wrap around the cracked area, increasing tension with each wrap.
Some tubing may stick when removed, but this can be gently scraped off with a sharp knife.
