Cymbal Repair
These tips on cymbal repairs are only temporary fixes. It is highly recommended that when your cymbals crack and break, you replace them.
Provided the crack is a small one, you can take a 2 part epoxy and fill the crack with it. You can then bake it in your oven at 200 degrees for an hour, then let it cool for 24 hours before using it again.
If that doesn't work, you can take a small drill bit and drill a hole at the end of the crack to prevent it from spreading.
Another "quick fix" is actually notching out the crack, provided that the crack is on the edge of your cymbal.
What can also be done is you can put your cymbal on a lathe and have it turned past the crack. You have to make sure that it is deburred properly or you run the risk of cutting yourself.
The intriguing thing about turning your cymbal to a smaller size is this...
Let's say you have an 18" cymbal with a crack about a half of an inch long on the edge. You have it turned just past the crack. Now it's a 17" cymbal with a bell made for an 18" cymbal. That makes for an interesting sound. However, if the crack is long and your 18" cymbal is now 16" or smaller. Just throw it away. It will sound awful.
You can try the other techniques on cracks that are on the bell or the bow of your cymbal.