Sand off the sprues using #220-grit emery paper. Sand in a diagonal direction, then repeat the sanding in the opposite diagonal direction.

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Rotary-file the inside of rings very lightly. Do not remove to much metal in this procedure.

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Sand the inside of the rings using #280-grit emery paper. Repeat the procedure using #320grit emery paper.

Rubber-wheel the outside surfaces of the castings. Start with a coarse-grit wheel, then a medium-grit, and finish with a fine-grit wheel. Move the wheel in alternating diagonal directions using overlapping strokes.

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Buff-stick all flat surfaces using #280-grit emery paper, then #320-grit paper. Again, stroke in alternating diagonal directions and overlap the strokes.

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Using a unitized wheel, reduce the surface scratches left by the empty papers. Start with a #400, then a #500, and finish with a #600-girt wheel. Remember to use overlapping and alternating diagonal strokes.

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If porosity is present it the casting, lightly burnish or hammer the surface affected by pits. This can be done using a reciprocating hammer or burnisher. The hammer and burnisher should have surfaces that are highly polished.

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Polish the inside of rings with white cutting compound or leave a satin finish.

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Hallmark or stamp the Quality according to the alloys used in platinum. For example: “ Plat 90, Irid 10” for 90% platinum or “Plat” for 95% platinum.

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The outside surfaces should be buffed with white-cutting, then orange polishing compound. Buff the outside surface with the white cutting compound in a diagonal direction, then reverse the direction of the buffing to cross over the original direction. Repeat this operation using orange polishing compound.

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Flat-lap all flat surfaces using a white cutting compound. Clean the surface and repeat the lapping with orange polishing compound. Again, clean the surface when the operation is complete.

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Using a muslin buff charged with orange polishing compound, lightly buff the outside surfaces for luster. This should give a very high luster a reflective surface.

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(Note: Polishing compounds used are up to the individual. Compounds should be considered for desired speed in cutting or polishing.)