Quote Originally Posted by Lord Torath View Post
To further clarify, do you mean using gravity waves to compact material tightly enough that it forms a black hole? In such a case, the black hole will be as stable as any other black hole of its size.

Or focusing gravity waves so their pull is as strong as a black hole? In which case: see factotum's reply.
The latter, i meant a gravitational wave kugelblitz. I wasn't sure if there were relevant differences between light and gravity waves which would result in different properties of the black hole. Anyway, i got factotums answer.