Reply to Thread

Message:: [QUOTE="Conder101, post: 39294, member: 66"]<It is the result of gasses being trapped between the clad layers which expand and create the bubble when the coin is struck.>These bubbles are not created when the coin is struck.  Yes there is gas trapped between the layers but gas in compressable an even if there was a bubble in the planchet the force of the strike would simply compress the gas and give you a flat surface.  Some would suggest that the heat created from the striking causes the gas to expand and create the bubble post strike.  Well even though the mtal of the coin "flows" during the strike, it is  considered a cold flow or working of the metal.  Yes the coins come out of the press hot.  But they are still at a temperatue LESS than 200 degrees  Farenheit and at those temperatures the coppernickel clad layer is for all pratical purposes just as ridgid as it is at room tmperature.  That tiny bit of gas inside has no chance of deforming that cold metal to create a bubble in the coins surface. The only way it will form a buuble is throughthe application of intense heat which will incease the pressure of the gas.  Even then it won't form a bubble until the coppernickel starts to approach its melting point which is over 3000 degrees.[/QUOTE]