I see these "bumps" on this coin for the first time, while aware a lot you have seen them before, I have not. Can any of you explain to me what they are and how they happened? I will go out on a limb and guess that they probably are a result of the plating process?
What I see here are contact marks, probably from being in a bag with thousands of other cents. The L looks like a dull hit mark where as a sharper edge sliced through the B and E. Not sure on the R, but it looks small. Plating bubbles are a possibility, on Zincolns but not earlier Lincolns.
On this angle, I can see some machine damage on the outer edges of the devices. When the die wobbles a tiny bit, only thousandths of an inch, it creates the swiping phenomenon we see here. Also remember, that things are in reverse so the closer you get to the fields, the deeper the die stroke. That last little instant before the stroke is done, it wobbles and distorts the devices.
The picture doesn't show... you can feel them with your finger. They are bumps that you can feel and see above the plain of the coin. They look like little droplets of gold that hardened as they landed on the surface. Does that help?
Not contact marks. Those are very small Linear Plating Bubbles. http://www.error-ref.com/blisteredplating/
That's it. I followed the link. Linear Plating Bubbles. Thank you. So those are one of the things in Zincolns that lead to corrosion of the zinc planchet underneath?
If the copper plating is somehow compromised in any way such as the bubbles bursting then the zinc will be exposed to humidity and rot.
Die and stroke. Two horrible words that should not be mentioned together Oh and it's just a simple plating blister
I was trying to take a picture holding the coin up on it's end with my microscope but my hand was shaking too much. So there are air bubbles under the plating?
I was going to say that they need to come up with another alloy to manufacture these things with, but, from what I hear they aren't going to be around much longer anyway.
Copper plated zinc cents actually do last. Billions have been minted and the majority are in fair shape. Just an unlucky few that become damaged and get ruined.. Nothing major.
