Antique Way

Coin Shrinking and Can Crushing

1. A magnified of view of Washington's shrunken head. Although the pattern is basically maintained, there is some relative shifting between some of the features. The radiating lines on the shrunken coin are called "Luder's Lines". These are created as the coin is plastically deformed, and are parallel to the direction of the applied shrinking force. The lines clearly show the radial forces that were applied to the coin.

2. The reverse side of a Delaware quarter also showing radiating Luder's lines. The inner layer of a clad coin shrinks a bit more than the outer layers. This also causes some relative shifting of surface features. In fact, some features may actually move underneath others - notice how the letter "S" has shifted so that it's partially under the horse on the shrunken coin...

3. On certain coins, such as the Kennedy half dollar, the bust may become attractively "haloed" by radiating Luder lines. For reasons that are not completely understood, this occurs only on some Kennedy halves. The degree to which Luder's lines form is also a function of the alloys used in the coin.

4. A Japanese 5 Yen coin demonstrates how the compressive forces squeeze the entire coin. Not only does the coin shrink, but the center hole closes up in the process. This brass coin was shrunk with using 5,700 joules. Notice the distortion of the horizontal lines above the collapsed center hole.

5. A clad Eisenhower Dollar is reduced from about 1.5" to 1.125" using 6,500 joules. A small amount of "toroiding" (preferential thickening of the outermost portion of the coin) can be seen. It is thought that this is caused as the work coil explodes before entire coin could fully shrink. Higher voltage systems using smaller bank capacitance often show this effect to a much greater degree,

6. Although it's not obvious, the Sacagawea "Golden Dollar" (or "Brass Buck") is actually a clad coin. The outer layers are an alloy made from copper, zinc and manganese (called manganese brass), while the inner core consists of pure copper. The Sacagawea is one of the prettiest coins to shrink, since they usually show little relative shifting and distortion of surface features and seldom develop Luder's lines. This coin was shrunk at 6,500 joules.

7. A Susan B. Anthony (SBA) Dollar shows some interesting shifting of surface features. Compare the space between her chin and her left shoulder and the lettering just to the right of her chin between the original and shrunken coin. Also, compare the locations of the Denver mint mark. Unfortunately, even shrinking her doesn't make her any more attractive...

8. Due to its smaller size, a dime takes significantly less energy to shrink. This clad dime was hit with 6,000 joules. Roosevelt's features are altered a bit (he ages 30 years, develops a long nose and grows a Jay Leno chin). The result is a cute little M&M shaped pill of a coin that's only about 60% of its original diameter. At 6,300 joules, some melting of the coin's edges may occur.

9. A Canadian "Toonie" has the center loosened at 6,500 joules, but the center is still held captive. At 14,000 joules, Rob Stephens, a friend and fellow coin shrinker in Ontario, Canada was able to separate the coin into two independent pieces. However, his blast shield failed during the shot, and he sustained considerable damage to his lab from shrapnel from the exploding work coil.

10. A side view of a quarter that's been shrunk to the diameter of a dime. Minor force imbalances often create a bit of rippling to the coin's edges. Also, the better conducting copper layer of clad coins causes it to shrink more, resulting in an "Oreo Cookie" effect. The thickness proportionally increases as its diameter is reduced. A shrunken coin's volume and mass remain the same, and its density remains unchanged. There's no "Honey, I Shrunk the Kids!" magic involved in coin shrinking.

11. Once in a great while, a coin will shrink very unevenly due to the presence of hidden internal bonding defects between inner and outer cladding layers. During shrinking, these defects cause internal force imbalances which distort the shape of the coin in very unpredictable ways. Notice that even the actual outline of the coin is even distorted...

12. Here's the front side of the previous Kentucky Mutant Coin. It looks like poor ole' George has sprouted a real "honker" and aged another 30 years. But he's also been working out - just look at those huge neck muscles. He's also appears to have developed a mammary gland in the back of his head... must be from the steroids. These "Mutant Coins" could be considered the "error coins" of quarter shrinking..

13. Another form of "mutation" comes from a high voltage hobbyist in the UK, Mike Harrison. The grain pattern of the wooden dowels is impressed into an aluminum 1 Yen coin. Minor force imbalances can cause a coin to develop "waviness" during the shrinking process. The "stripes" which formed in this coin align with the grain pattern in wooden dowels that originally held the coin in the work coil.