Help with Kamado fire box repair

I have several cracks in my Kamado fire box rings. It's a really old one. Wondering what best to use for repair. Under what circumstances do I use each product. Saw the 2010 post using JB Weld and postings suggesting furnace cement. Need to know if these products are safe used with food. If OK then what is repair timeline to dry and go through initial heat up. Any gases to burn off, etcetera. Thanks for suggestions and help. Any other suggestions for restoration?
Liz 503-989-8993