{HEAD ~ Virgin sand} may be added to {TAIL ~ 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 mixture of the salvaged sand and the virgin sand 
added to
{ HEAD ~ Virgin sand } may be added to { TAIL ~ 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 mixture of the salvaged sand and the virgin sand
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL 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