Looks like a nice project ! Just to let you know, you can re-use that sand over and over if you screen out the big chunks before pouring it back into the pressure pot . We use Aluminum oxide here at work on aircraft and oilfield parts, but it works the same. Just chunk it after it gets so fine it doesn't cut anymore. All the sand does is break down into finer and finer grit as you go. Good luck on the project !
Rick