Here is a great video of a couple of guys who built a really nice sluice box for under $70.00. They have everything covered. They are using three different types of matting, and miners moss. They even cut their own expanded metal, and made their own metal riffle system that bolts in place. If you are thinking about building your own sluice box, watch this video. It may give you a few ideas on how to make one for yourself.