Cob floor for blacksmith shop

We are installing a cob floor in an out building that will be used for storage and a blacksmith shop. We’re using local clay heavy dirt with lots of straw. There is a cracked concrete foundation under about five inches of packed fill dirt. The cob is on top of that. It’s been hard heavy work and I’ve made to 2/3 of the way across the space. I am planning to put a clay sand layer on top that we will seal with tung and turpentine. I started this project because my son wanted an earthen floor in his shop. Now, after tremendous effort and investment, I’m hoping this floor is going to work for a shop? Does anyone have any helpful advice or input? I’m probably looking for reassurance, but any advice is welcome.