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I think I bought a fake. Help, please.
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<p>[QUOTE="TIF, post: 3006018, member: 56859"]Yes, it is. Don't forget about the distortion introduced by the different angles of photography.</p><p><br /></p><p><br /></p><p><br /></p><p>I think the graffito is on the host coin (the authentic coin) and it has subsequently transferred to the mold and then to each copy, with some differences in depth and quality of the graffito as would be expected from casts.</p><p><br /></p><p><br /></p><p><br /></p><p>I doesn't seem smart for the forger to do this, does it? I suspect the answer is that it takes extra work (see the detailed explanation that follows), and apparently they have had success passing forgeries without sweating the details, so why bother?</p><p><br /></p><p>Using what I know about lost wax casting, which is presumably the method by which these cast forgeries are made, here are the steps:</p><p><br /></p><p>1. Make a vulcanized rubber mold of the authentic coin. Think of the mold as a "negative" of the coin, including its surface imperfections and characteristics.</p><p>2. Split the mold to remove the coin. The mold is split in such a way that it can be "keyed" together, holding the two halves in proper alignment. The mold incorporates a funnel, which is the conduit for the wax in the next step and also provides a "stem" for the molten metal egress.</p><p>3. Using a wax injector, fill up the mold.</p><p>4. When the wax has hardened, open the mold and remove the wax copy. Note that this copy is a "positive". Repeat steps 3 and 4 until you've made as many copies as desired.</p><p>5. Encase the wax in a plaster-like substance called "investment". The stem of wax is left protruding above the surface to provide a hole for receiving the molten metal (this becomes the "sprue). Multiple waxes can be sprued together into a tree, casting many dozens in one go.</p><p>6. The investment-encased wax copy is fired in a kiln to melt off all of the wax</p><p>7. Molten metal is poured into the investment mold, using centrifugal force or a vacuum to ensure good fill.</p><p>8. The entire thing is dunked into water, cooling the metal and breaking apart the investment. The sprue and any seams are removed and the coin cleaned up and artificially aged.</p><p><br /></p><p>Options for removing graffito:</p><p><br /></p><p>A. Ideally, the graffito would be removed prior to making the mold, but that would likely damage the original coin.</p><p>B. Remove the grafitto on each wax copy, one copy at a time. The wax could be filled in or a small heated tool applied to the scratch to melt the wax in that area. Not difficult to do, but unless done very carefully it will leave an area that looks altered, perhaps raising more of a red flag than would the original graffito... unless an astute collector later spots a coin with identical grafitto and virtually identical flan.</p><p>C. Remove the graffito on the cast copy, which incurs the same problems as B.[/QUOTE]</p><p><br /></p>
[QUOTE="TIF, post: 3006018, member: 56859"]Yes, it is. Don't forget about the distortion introduced by the different angles of photography. I think the graffito is on the host coin (the authentic coin) and it has subsequently transferred to the mold and then to each copy, with some differences in depth and quality of the graffito as would be expected from casts. I doesn't seem smart for the forger to do this, does it? I suspect the answer is that it takes extra work (see the detailed explanation that follows), and apparently they have had success passing forgeries without sweating the details, so why bother? Using what I know about lost wax casting, which is presumably the method by which these cast forgeries are made, here are the steps: 1. Make a vulcanized rubber mold of the authentic coin. Think of the mold as a "negative" of the coin, including its surface imperfections and characteristics. 2. Split the mold to remove the coin. The mold is split in such a way that it can be "keyed" together, holding the two halves in proper alignment. The mold incorporates a funnel, which is the conduit for the wax in the next step and also provides a "stem" for the molten metal egress. 3. Using a wax injector, fill up the mold. 4. When the wax has hardened, open the mold and remove the wax copy. Note that this copy is a "positive". Repeat steps 3 and 4 until you've made as many copies as desired. 5. Encase the wax in a plaster-like substance called "investment". The stem of wax is left protruding above the surface to provide a hole for receiving the molten metal (this becomes the "sprue). Multiple waxes can be sprued together into a tree, casting many dozens in one go. 6. The investment-encased wax copy is fired in a kiln to melt off all of the wax 7. Molten metal is poured into the investment mold, using centrifugal force or a vacuum to ensure good fill. 8. The entire thing is dunked into water, cooling the metal and breaking apart the investment. The sprue and any seams are removed and the coin cleaned up and artificially aged. Options for removing graffito: A. Ideally, the graffito would be removed prior to making the mold, but that would likely damage the original coin. B. Remove the grafitto on each wax copy, one copy at a time. The wax could be filled in or a small heated tool applied to the scratch to melt the wax in that area. Not difficult to do, but unless done very carefully it will leave an area that looks altered, perhaps raising more of a red flag than would the original graffito... unless an astute collector later spots a coin with identical grafitto and virtually identical flan. C. Remove the graffito on the cast copy, which incurs the same problems as B.[/QUOTE]
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I think I bought a fake. Help, please.
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