Die polish lines?

Thanks for jumping Mike. Please tell us more. What the heck is a rotating descaling brush?

 

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A rotating descaling brush cleans the clad and core strip before they enter the bonding mill. Usually this is done only on the side intended to be bonded. But I suppose mistakes can happen or a diffirent procedure applied. If you look at a split-after-strike clad layer or a missing clad error where the clad layer fell off after the strike, the exposed surface is usually covered by similar-looking parallel lines.

 

Thanks for that info Mike!

 

Mike closed the case, thank god.

One more thing though... is there any chance at all this is all in the toning and just an illusion?

 

Thank you!

 

Incuse marks on planchets are more likely to survive the strike than raised marks. There are probably several sources for closely-spaced parallel lines. Some are incuse, some appear raised, and some appear flush with the field. Its an area about which much uncertainty remains.

 

Mike, Regarding "die scratches" on coins, are these caused by some type of polishing method or by something different entirely? Thanks, Jody

 

Wire brushes, emery sticks, and other abrasive tools are employed. Scratches vary in thickness from course to fine, pointing to the use of different abrasives.

 

Thanks again Mike! A wire brush would also make sense for the lines that show up on the devices.

 

Die scratches arising from intentional die abrasion are largely confined to the field. However, they can show up in low relief areas, like the corner of the eye or the center of the ear.

The abrasive tools can be used to remove signs of die damage and also to clean rust spots and accumulations of compacted gunk. Basically any shallow die imperfection and any accumulation of dirt can be addressed by these methods.

 

Mike, I would assume that descaling occurs just prior to bonding and within the same production process. If not, then what is the likelyhood that both obverse and reverse clad strips were inverted prior to bonding and given the fact that the clad stock is coiled into rolls for blanking, wouldn't there be far more of these coins around?

Of course I am assuming that the clad stock was shipped in rolls such as they are today as I have no hard evidence to verify that claim.

 

The Mint brings in coils of clad strip already cleaned by its suppliers. I don't know if they ever descale on both sides. I would assume one side is typical since dime and quarter planchets have a smooth outer face. You make a good point that these streaky planchets should be more common if these are typical rolling marks or descaling scratches. So perhaps there is a different source.

 

What a cool thread. And Mr. Diamond, I wish you would stop by more often!

 

Reviving old thread...

The more I look for these sort of details, the more I gravitate to the conclusion that you might be wrong.

I disagree. It does not look like a whizzed coin to me.

 

I just read through the entire thread and have question. Are working hubs ever polished? If so, would "hub scratches" then produce raised lines on the working die, and, thus, incuse lines on the coin? I'm not arguing that this is in any way involved in the condition of OP's coin. Just for my own edification.

 

Time for a contention adjustment. Maybe getting back into coins, searching these out and providing photos of what you find, would help prove or disprove this vague repetitive view of yours. As it sits, you're talking, but, failing to convince the several perceptive individuals that actually hold some of these coins of "uncertainty" in hand and manage to provide decent photos to back up their findings. What proof have you presented, other than your claim to understand "... about how dies are treated and processes are used with dies."?

 

It's very possible that you do not understand what has been said here.
It's not a black and white issue. Study it for 40 or 50 years and tell us your opinion.