Coin Mokume to use as a bolster I would think it would need to be hardened can someone tell me how this works 

How what works?

Making mokume gane discussions and tutorials are easily found all over the web with a little search. Learning how to harden nonferrous alloys can also be found with a quick search. 

Sorry guys should of Googled it first man did I ever over think this process it work hardens 

I wouldn't expect hardening it would be necessary for a bolster, but you are correct that it can be work hardened. Hammer it down to a bit over your finished dimensions without annealing and then just sand/file/whatever to finished size.