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 Replies: 22 / Views: 11,321 |
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Valued Member
Finland
294 Posts |
I saw few interesting coins in plastic cube (made for souvenirs, gifts etc.) in second hand shop. Can I broke the cube and get the coins off in good shape? Nails and hammer...  |
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Bedrock of the Community
Australia
21786 Posts |
I would buy the cube and keep the coins in it. It would make an interesting table piece, and a good talking point.
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Moderator
 Australia
16826 Posts |
I have seen such souvenirs, coins entombed in Perspex or some other clear plastic. I even have an old one from Canada in the 1970s.
I'd tend to agree with sel: I'd keep the coins in there, unless the coins are super-rare and/or you need them to complete a set and cannot obtain similar coins by any other means. The plastic has probably done a pretty good job at preserving the coins, probably better than any 2x2 or album a collector would more typically use.
If you have to liberate them, I would use caution. It'd be easy to damage them with a careless hammer blow. You might also need a good supply of solvent (such as acetone) to get any residual plastic off the coin.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Pillar of the Community
United States
2150 Posts |
I have heard these are almost impossible to open up and get the coins out.
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Bedrock of the Community
United States
20753 Posts |
If it's anything like this:  Forget it. Any attempts to break out such coins may well do more damage than you could imagine. And then too how would you get all the plastic off the coin. |
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Forum Dad
United States
24154 Posts |
One thing is for sure. A big hammer won't work....  That was my handy work back in 2005.  My most optimistic, although unconfirmed, suggestion would be to take it to your local high school chemistry department and see if they will give it a dunk in the liquid nitrogen and shatter it. I have a sneaky suspicion that just might work. |
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Bedrock of the Community
United States
36744 Posts |
These are all molded or poured so the chance of getting the coin out without damaging it are very slim. Best to leave it as a novelty item.
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Valued Member
 Finland
294 Posts |
Thanks for your wise responses guys - there's no sense to try to take coins off that cube. Now I have to just win the organizer part of me who wants to put every coin into 2x2's and then binders. Sel's talking point advise was quite a good so perhaps I'll go back to the shop and buy the cube for four euros.
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Pillar of the Community
United States
4132 Posts |
Maybe you could saw off as much of the plastic as possible with a hacksaw, then remove the rest with acetone (assuming the plastic is the sort dissolved by acetone). Might end up going through more acetone than the coin is worth, though.
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Bedrock of the Community
United States
17884 Posts |
Use a band saw to remove as much of the excess plastic as possible. Immerse in liquid nitrogen. The extreme cold of the nitrogen will make the plastic extremely brittle and the very different expansion rates of the two materials will cause the plastic to pop loose from the surface of the coin. Remove the coin plastic lump from the nitrogen and hit with hard plastic mallet or a a hammer through a wood block. The brittle plastic will shatter and come away from the coin. It can be done, but in most cases it isn't worth the time, effort, or expense. By the way if you do this be very careful handling the nitrogen. If you don't know what you are doing, it can be very dangerous.
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Forum Dad
United States
24154 Posts |
Sawing that stuff is very difficult, the friction makes the plastic melt almost instantly and gums up the blade.
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Bedrock of the Community
United States
20753 Posts |
Quote:
Sawing that stuff is very difficult, the friction makes the plastic melt almost instantly and gums up the blade. I too found that out attempting to free coins from slabs. Using a Dremel or Saber saw with a metal cutting blade is almost fun. As fast as you can move, the blade starts to get hot and remelts the plastic right back to where it was. A harsh toothed blade for rough cutting wood usually shatters the plastic. Going to any shool and asking if you could use some liquid Nitrogen might be fun watching them call the police. Going to any school and asking to use their chem lab is something I'd like to watch with all the things happening with chemicals. Back to that coin in plastic. One sure method would be a Butane Torch. Yes it will possibly melt all the plastic, create plumes of deadly gasses, damage the surface of the coin. BUT it will be out of that plastic. MAYBE.   |
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Bedrock of the Community
United States
10038 Posts |
Liquid Nitrogen can be bought by anyone and is inexpensive. Contact a local company that handles CO2 and O2 tanks. Do some googling to find out a safe way to store/transport it though - or even ask the supplier. I used to get it for my chemistry classes and the kids loved it the class demonstrations. I actually just got a large styrofoam (thick - not dollar store special) cooler, they filled it. and we tightly taped/bungie cord wrapped it. The container went into the trunk (made it so it would not move). Even if there had been an accident and it was hit, it would have evaporated so quickly that no harm would have been done.
How much squash could a Sasquatch squash if a Sasquatch would squash squash? Download and read: Grading the graders Costly TPG ineptitude and No FG Kennedy halveshttps://ln5.sync.com/dl/7ca91bdd0/w...i3b-rbj9fir2 |
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New Member
United States
17 Posts |
Maybe buy a few 5 packs of cheap saw-zall blades made for wood cutting. Lock it in a vice and put it some time cutting through it slowly. Or if just a hammer didn't work, maybe a hammer and chisel? Whatever you do make sure you wear eye protection, it would not be fun to take a 1/4" piece of plastic to the eye ball!!
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Forum Dad
United States
24154 Posts |
Quote:
Or if just a hammer didn't work, maybe a hammer and chisel? Be very careful you don't pull a Bryce Harper when you do. This stuff feels very hard in your hand, but when you hit it with a hammer it's like hitting a golf ball. |
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Pillar of the Community
United States
1231 Posts |
PMMA Poly(methyl methacrylate) which is typically used to make these cube,can be removed with any of the following....acetone, benzene, chloroform, MEK, THF.
But without access to a lab you won't be using most of those
Edited by onejinx
06/23/2012 10:47 am
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Replies: 22 / Views: 11,321 |
Posted 06/21/2012 08:16 am
