Let me show you the process I use and then at the end of this post I will include a link to someone else's process. The two different processes should give you a good idea of what needs to be done.
This is what my native clay looks like fresh off the pile my husband made. Besides your normal pebbles, sand, and impurities, I have crabgrass, bugs and anything else that might find itself on top of a pile of dirt outside.
So What is the Process for Cleaning this Mess?
The first thing I do is dry the clay completely. I have two methods for doing this: Either I spread a wagon-full directly onto my garage floor where the cement will soak up the moisture as it sits underneath my car
The only item I needed to purchase to wash my clay was the sieve. I had tried the window screen as others have mentioned but did not like using it. The screen I used also let too much sand pass through. I have a lot of sand in my clay so I spent some time researching trying to figure out what size mesh I should use to get the right amount of sand removal. I finally decided to try 3 sizes; 60, 80 and 100 mesh. The eighty works well for my needs.
That's it. That's my process. I have each phase of this process going at any given time so that I always have clay available when I need it. Now here is the link to the other process that I promised you. Have fun!
If you have a different process for cleaning your native clay, mind sharing?