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<p>[QUOTE=&quot;gsimonel, post: 4431471, member: 82549&quot;]What you are describing is corrosion, not bronze disease (BD). They are similar, but not exactly the same. It&#039;s sort of like the difference between scars and skin cancer. Scars (forgive me if I&#039;m offending anyone) can be unsightly, but they won&#039;t spread. Skin cancer, however, can continue to spread and cause additional damage.</p><p><br /></p><p>Corrosion is caused by the interaction of the coin with chemicals in its immediate environment, i.e. the ground surrounding it. Once the coin is removed from that environment, the corroding process ceases. But you are still left with a (usually) hard blob on the surface of the coin that is some combination of materials from the coin and materials from the environment. So removing the corrosion removes any of the metal from the coin that has reacted to the chemistry of the environment. Presto: surface pitting. Scars.</p><p><br /></p><p>BD starts the same way, but there is a critical difference. The nasty chemicals turning your bronze coin into powder remain with the coin even after it has been removed from its recent environment. The only way to stop the reaction is to either neutralize it chemically or leach it out of the coin with distilled water.</p><p><br /></p><p><br /></p><p>I&#039;ve never baked a coin after treating it for BD, but I can understand why someone might want to. The point is to remove any last traces of moisture within the coin, since it&#039;s the moisture--usually in the air--that allows the chemical reactions causing BD to occur. But two points:</p><p>1) I would do it at a lower temperature. Seems like there would be less chance of damaging the coin. I&#039;ve heard of people baking post-treatment coins at 200 degrees Fahrenheit for an hour or so. But that&#039;s just my instinct. I have not evidence to back this bias up with.</p><p>2) To cure BD you really need to remove all the chemicals (chlorites? chlorides?) that are causing it. Removing all the moisture will stop the reaction--since they need moisture to occur--but it might give you a &quot;false negative&quot;. That is, even though you&#039;ve stopped the reaction, there might still be some reactants left in the coin that you haven&#039;t completely gotten rid of. It&#039;s possible that under the right conditions, the BD might return.[/QUOTE]</p><p><br /></p>

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