8. fold the plate with the gold in it into a v shape. 9. pour the gold onto plate 2. you will notice that the dry gold pours off first, and it always leaves a little black residue in the crease of the v in plate 1. 10. pour the black residue on to plate 3. 11. repeat by pouring the dry gold that is now on plate 2 onto plate 1. 12.,water powered gold prospecting and gold mining equipment,how to clean gold. sometimes placer gold comes out of a stream with a thin coating of mercury or other impurity attached to it, so it is necessary to clean your gold to bring out its natural luster and shine. the best way to clean gold is to place it in a small water-tight container about half full of water and add a bit of dishwashing liquid.