What not to do, is what I did. Dont cut it in two, soak in detergent water solution. Then put borax on it in a thick coat and let it set. Be cause when you tap it together a couple of days later to knock the excess off, it will break in many pieces.
thanks for listening mater
If by "detergent water" you mean water with bleach thenthat is why it came apart. I learned to never use bleach on bone when I started doing skull mounts.