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New Member
United States
5 Posts |
Hmmm.... I dont have LN2 readily available. I wonder if I can get a cold enough temp. to crack the plastic by using a can of compressed air?
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New Member
United States
5 Posts |
Ugly have you had much success with boiling them? I am also looking to do this for the colored Olympic coins that are embedded in plastic. I believe they were sold by Petro Canada. Again, thanks for your replies everyone :)
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Moderator
 Canada
10463 Posts |
Put them in a glass with boiling water, then take that boiling water with the coin in it, and microwave the heck out of it, get that water really hot for a sustained period. Then, you can grab the caps with a needle, and pry them off. But, don't pry the caps all the way, just a bit and curl it out so you can grab later with pliers. If you pull the cap off a hot coin, the paint will come with it. Cool the coin in the freezer, then grab the curled up plastic cap and pry it off the coin. Voila.
The real challenge is trying to get the plastic caps off the 2006 mint report (with the gold plated Victoria nickel). Acetone works great on one side, I had to use liquid nitrogen on the other. You have to be REALLY careful, since it is a silver proof strike. The bookmark olympic loon is another challenge, it is also a proof strike, and have not yet been able to get the obverse of the coin free of the plastic without damaging the coin. I believe it is the ONLY proof struck olympic loon (not the silver lucky loon). Any figure this one out yet?
"Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
Edited by SPP-Ottawa
05/20/2011 8:37 pm
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Pillar of the Community
Canada
1733 Posts |
@ponz Yeah I toss them in the pressure canner with distilled water they come right off. I just hold the coin in a cotton towel and the plastic is so soft a fingernail will take it up out of the rim beads/denticles/morse code. Occasionally a little help from a hard plastic tool like what is used to split notebook shells can be of assistance in just getting the edge up - it's about the hardness of a lotto ticket scratcher thingy majiggy (big tech language here)...
If you're doing poppy quarters like SPP mentioned, his technique is great but I'm impatient and I use compound W freeze off on the metal coin to cool it on the obverse and this cools the metal and coloured insert while leaving the acrylic still warm and pliable for the most part.
The one that I dunked in LN2 was a carded standard quarter, not a coloured quarter.
The bookmark Olympic loon I haven't tried.
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Pillar of the Community
 Canada
9868 Posts |
Like ponz I tried the solvent method,the result was an uncoloured poppy
Like northof49 I tried boiling without success,maybe I'll try boiling a lot longer
Sure would like to get the poppy quarter out of it's plastic lump and into an airtite
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Pillar of the Community
Canada
1733 Posts |
Well, by using the pressure canner I can surpass the standard boiling point of water significantly and get it up to around 240F instead of 212 and I've also been known to boil things is corn syrup for the same reason. Nothing about the sugars in coin syrup are very reactive so I'd experiment with it, you should be able to get the acrylic up around 235F no problemo... a little messy though, that's why I like the canner.
Plus I actually can food so it's not really a coin thing... I keep telling myself that anyhow.
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Pillar of the Community
Canada
9868 Posts |
Thanks Ugly,I know my wife has a pressure cooker around here somewhere.
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New Member
United States
5 Posts |
SSP a question for you? Wouldn't the acetone bath work well on the proof coins? I would think it would dissolve the plastic on both sides of the coin. At least there is no enamel coloring that will melt off when you do this. I have used acetone to dip proof coins with success. Have a fan nearby. The breeze of the fan air dries the coins quick after the acetone bath. RE: the gold plated Victoria nickels, wouldn't the acetone work on both sides? I would think this would also work well on the proof Olympic loon.
This is becoming an obsession although I honestly love the challenge lol. I am afraid of microwaving the coin for fear I might burn down the house. I have always been to told never to put objects containing metal in the microwave. I do have a pressure cooker that I never use. How long do you have to leave it cooking under high pressure for it to be "done?" God I hope I don't blow up the kitchen. Thanks guys!
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Pillar of the Community
Canada
1733 Posts |
SPP also has the potential to dry his acetone with a molecular sieve using Zeolite A3 before he does this, no crappy water spots !
@ponz, I leave it to boil for ten minutes, that's enough to reach maximum temp. I use distilled water and I wrap the coin in cheesecloth to keep it from touching the pot itself (for fear of corrosive action).
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Valued Member
Canada
370 Posts |
Has anyone had any success with the Olympic loon bookmark?
I don't want to risk messing up the coin unless I know it's possible to remove it from the plastic.
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Moderator
Canada
10463 Posts |
I can only get the reverse cap off... the obverse cap remains a challenge. I have placed a bookmark, obverse up, in a sunny window sill for about year now - it is turning yellow. I am hoping to get enough UV light degradation to have the cap come off... might take another year or two yet...
"Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Pillar of the Community
Canada
2366 Posts |
I did a loonie covered in the same stuff that came out of one of those credit card sized cards. Had to boil it longer than I expected and then suddenly it went soft and came off.
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Pillar of the Community
Canada
9868 Posts |
Two years later,and I still haven't tried the pressure cooker method as suggested by ugly,lest I ruin my last bookmark quarter.
"Dipping" is not considered cleaning...
-from PCGS website
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Valued Member
Canada
370 Posts |
SPP, if you are able to remove the reverse cap, could you not just pry the obverse off?
I guess the biggest challenge would be not damaging the proof finish.
I would thing that if the plastic was soft enough that the coin could just be popped out.
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Moderator
Canada
10463 Posts |
For that proof loon, there are two different types of plastics used, for each side...
"Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Posted 05/20/2011 7:57 pm
