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 Replies: 10 / Views: 1,425 |
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Pillar of the Community
United States
751 Posts |
I have somewhat of a problem with the polishing idea of the floating roof coin. If you look at the end of the area where the missing line is, you can see it's rather deep, how can someone polish BOTH sides of the monuments die, and not effect the upper or lower segments of the coin at that spot. If you look at the closeup, you can plainly see the spot above and below the area are both sharp. I find that very hard to grasp as the cause, that someone polished it to a perfect taper, and did not even slightly effect above or below. That is a very narrow area to polish that fine of a line. The space between the red arrows is VERY TINY, Yet you see no wear at the areas by the blue arrows. Someone would have to be using high magnification and deliberately trying to polish that area away without doing ANY collateral damage. I know this is commonly accepted, but study the photo and think about it. I have no alternative cause in mind, just have doubts about the accepted one. Dan   Edited by Panther
01/02/2019 3:19 pm
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Pillar of the Community
United States
5887 Posts |
Maybe there was an issue with the dies around that small little area. Some kind of error or die problem that the mint needed to get rid of. Maybe they polished away any of the areas showing this. As for the FG and shirt, those look to be common places for die polishing on many coins. Maybe someday we will find an example that got out with the error?Just an idea! Probably not likely. Happy hunting!
Edit: just thought of something else. PCGS used to certify these floating roof pennies, but stopped because they realized there was too many out there, and it wasn't a "variety" of sorts. If this is true, and they realized it was polishing, why is the no FG variety still being certified? Wouldn't that be an easy one to find as well, or is that die harder to locate.
-CH27
Collector of U.S. Coins, Varieties, and Colonial Coinage
Edited by CoinHunter27
01/02/2019 4:00 pm
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Bedrock of the Community
United States
62064 Posts |
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Moderator
 United States
56855 Posts |
Keep in mind that everything that is raised on the coin is sunk in on the die,I think that has something to do with it. John1  |
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Pillar of the Community
 United States
751 Posts |
When you have the die clash, like you pictured Coop, How come it doesn't effect any other part of the coin, except the ends of the roof support, and doesn't it seem odd it happens on BOTH ends ?
I still think something else is going on there. I don't know exactly what, but the clash and polishing ideas, leave too many coincidences to have to occur, to make BOTH ends disappear and nothing else gets damaged. Odds seem too high.
Dan
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Pillar of the Community
United States
2775 Posts |
Panther, I'll assume your referring to either a 1969 or 1970 LMC. Allow me a little patients and more food for thought will follow. Thanks, Doug. Edited by Halo1st
01/02/2019 9:25 pm
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Bedrock of the Community
Canada
21630 Posts |
Ass we all know, the raised parts of a coin are incuse in the striking die.
These can be various depths. When a die is polished, the shallow depths sometimes get polished away.
In the case of your coin, there is a die clash at both ends of the roof. The vertical lines at the end of the
roof are shallower than the rest of the roof so when the die is polished,these can get removed without
affecting the rest of the coin, thus resulting in a floating roof.
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Bedrock of the Community
United States
62064 Posts |
You got it. The only point you missed was that the fields are the outside part of the die. So during a clash the fields outline of the devices make a mark when the close together. If a very strong clash happens, you can even see the devices and even the date. I have a few images, but probably no one want to see them?
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Bedrock of the Community
United States
17884 Posts |
Something else you have to remember is that the entire field of the die is ground down not just the areas at the ends of the roof. Since the lines at either end of the roof are of basically of equal depth, and considerably shallower than the lines of the roof above and below, both end "supports" tend to disappear at the same time leaving the upper section floating. When the die is ground down like that all the shallowest features disappear first and the shallowest features on the LMC tend to be the lines at the ends of the roof. Edited by Conder101
01/02/2019 11:35 pm
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Pillar of the Community
United States
2775 Posts |
More food for thought. When the floating roof was thought to be a common issue that occurred on any given year. My research done back then found 99% of memorial cents exhibiting full double sided (abraded) floating roof were from the years 1969 and 1970. The remaining 1% is not set to memory as I can't recall any other year that shows both sides fully abraided in the same fashion, much less multiple dies from the same years. Of that 99%, the majority working die examples were in production at the Denver and San Francisco mints. Some produced from the Philadelphia mint was found as well, but less common. Side note: PCGS listed 1969D FS-901 no FG do to the missing intials, but soon found more than one die was effected and stopped slabbing them as a unique die variety soon there after. Another time line: In 1969 a new reverse (RDV-002) as well as obverse (ODV-024) designs were introduced. Also note this year the alignment lugs used for the multi squeeze hubbing and die alignments were discontinued due to hubbing issues. Some thought to be a contributing factor to the major 1969S Class I DDO. Several other DDO's were produced between that year and 1972 including another major Class I DDO from Philadelphia and the alignment lugs were reintrodused in 1973. The full double sided floating roof seem to stop after 1970. Note: the arival of the RDV-008(?) design was put in production along with the RDV-002 design in 1971 and would seem to follow into 1972. Again I've seen some other years come close, but not completely abraded after 1970. In 1973 the RDV-003 design was introduced and the 1969-72 RDV-002 design was no more. To summerise I can only speculate and assume the dies were annealed and hardened proper, as I was not present to see the 1969 - 1970 initial hub or die impressions. But I do still wonder if the reverse hubbing and or die impressions might have been lacking in some respect during this time period to start with? If so that could explain the acceleration of the process of what it actually is, a seemingly hastened die abrasion issue. I'm under the impression all working hubs and working dies were manufactured at the Philadelphia mint and distributed to the other mints production plants during this time period. Thanks, Doug. edit: typos Edited by Halo1st
01/03/2019 12:11 pm
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Pillar of the Community
United States
751 Posts |
Maybe it would also help if someone could explain what process and equipment is used to facilitate the grinding and polishing process. Do any photographs exist while the process is being done ?
Dan
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Replies: 10 / Views: 1,425 |
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Posted 01/02/2019 4:27 pm
