Virgin sand may be added to the salvaged sand as needed and when virgin sand is added to the salvaged sand, the term the salvaged sand before kneading should be broadly interpreted to include {HEAD ~ mixture} of {TAIL ~ the salvaged sand} and the virgin sand 
of
Virgin sand may be added to the salvaged sand as needed and when virgin sand is added to the salvaged sand , the term the salvaged sand before kneading should be broadly interpreted to include { HEAD ~ mixture } of { TAIL ~ the salvaged sand } and the virgin sand
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH