I'd have to consider the economics of it. Quarters and dimes are, as you say, mostly copper, BUT there are costs associated with extracting the copper from these coins. If the cost to extract is more than the value of the actual copper, no smelter or dealer would want them.
It's sort of like silver plate flatware. Sure there is a modicum of silver in them, but it costs more to extract the silver than the spot price of the actual silver content; therefore, no one wants silver plate.
So I will continue hoarding the nickels, as nickel does have some industrial value. Still not sold on the dimes, quarters and pennies.
I'd have to consider the economics of it. Quarters and dimes are, as you say, mostly copper, BUT there are costs associated with extracting the copper from these coins. If the cost to extract is more than the value of the actual copper, no smelter or dealer would want them.
It's sort of like silver plate flatware. Sure there is a modicum of silver in them, but it costs more to extract the silver than the spot price of the actual silver content; therefore, no one wants silver plate.
So I will continue hoarding the nickels, as nickel does have some industrial value. Still not sold on the dimes, quarters and pennies.