I like using the Brownell's glass bedding compound that comes in the green box. It is the slow setting brown colored one used for repairs and glass bedding projects. Mix up some in that, spread that Crack wide open, and smear it full, then wrap it with surgical tubing where ya can stretch it and wrap it tight. Once the bedding jell is mostly dried, I like to unwrap the tubing or cut it off usually. Then with a sharp knife edged tool of some kind, cut and scrape some of that mostly dried bedding compound away, as I will make the job of finishing later much easier with less rock hard compound to deal with. Once the job is done, you'll probably never break it in that same place twice.