Need some ideas on expanding the outer edge

No problem. It’s just that silver coins are real soft compared to copper clad coins. In fact, I remember as a kid... taking a silver quarter.....drilling a hole in it for my finger. Then.....I’d sit in front of the TV and tap the edges with a tablespoon for hours. Before you know it....the edges were mashed out and presto, I had a silver ring. This was like 1972. Flower Power and hippie stuff.
But it was interesting how fast one could fashion a ring out of a silver quarter by just tapping on the edges with a spoon.
 
That shell looks like it is a stamped piece, most likely they had a die made to match the side of the coin and the edge then stamped them from a solid disc to create the cup and imprint the coin face all in one motion. I don't believe they modified an actual coin.
 
Papa Charlie. I think you’re correct. I vaguely remember an article or video on how someone made some of these coin shells. I’m thinking that a plaster mold is made of a 50 cent piece by doing multiple thin dips of the coin into thinned plaster so that you have a clear representation of the coin face.... and somehow through the process of plaster molds and silicone molds... finally a die is cast which is now larger. By dipping into plaster.... removing....dipping.....and repeating this process a few times, one ends up with a slightly larger representation plaster mold of the coin. Then the silicone mold is made of this and finally the reverse can be cast using plaster.
You now have a pattern which represents the coin but is large enough for the shell so you can fit the original sized 50 cent piece into it.
As far as the die to stamp your shells....Just needs to be a metal hard enough to form a soft silver alloy. Maybe a silver / lead , Zinc, or tin based alloy in which you can then form your shell. And although cast iron is obviously great for a die... maybe a hard bronze will suffice. No matter what, we are talking about a lot of work.
But I vaguely think that the thin dipping into plaster is what gets you to a 50 cents piece which is a little bigger than the original. As far as exacting metal alloys....just not my forte. But I’m think copper based alloys give you harder metals. Lead and zinc give you softer ones.

Personally, to find out more.... I’d shoot an email to Clicksprings / Ramnsey’s website. Or ask him on one of his videos for maybe pointing you in the right direction. I’m betting he would know how it’s done. That’s one talented guy in my opinion. There’s bound to be something out there somewhere.
All that said....it’s a heck of a lot of work and probably cheaper to just buy one.

Expanded Shell - Half Dollar (Head) - Tango D0001

Expanded Shell Half Dollar (Head) by Tango
www.propdog.co.uk www.propdog.co.uk

not saying it’s cheap. But by the time you tool up and buy your supplies to make one, it’s still more cost affective.
 
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It is possible to swell or shrink silicone moulds with the use of a solvent such as acetone or toluene. To achieve a larger than original casting the silicone mould is soaked in the solvent which causes it to swell. The yield is a larger than original casting. To achieve a smaller casting than original the solvent is mixed into the liquid moulding material when it is being prepared. As the silicone cures the solvent off-gasses and yields a smaller than original mould.

There is a practical limit of expansion or shrinkage and some distortion can occur at larger ratios, but for small variances I believe the results would be convincing. I’ve used the Smooth-On line of moulding products pretty exclusively and they have a pretty good Q&A section on the website for more information on stuff like this.

-frank
 
Papa Charlie said:
That shell looks like it is a stamped piece, most likely they had a die made to match the side of the coin and the edge then stamped them from a solid disc to create the cup and imprint the coin face all in one motion. I don't believe they modified an actual coin.
Click to expand...
the silver one from johnson i looked at under microscope found traces of solder does this help anyone?
 
francist said:
It is possible to swell or shrink silicone moulds with the use of a solvent such as acetone or toluene. To achieve a larger than original casting the silicone mould is soaked in the solvent which causes it to swell. The yield is a larger than original casting. To achieve a smaller casting than original the solvent is mixed into the liquid moulding material when it is being prepared. As the silicone cures the solvent off-gasses and yields a smaller than original mould.

There is a practical limit of expansion or shrinkage and some distortion can occur at larger ratios, but for small variances I believe the results would be convincing. I’ve used the Smooth-On line of moulding products pretty exclusively and they have a pretty good Q&A section on the website for more information on stuff like this.

-frank
Click to expand...
where talking about metal coin
 
Tim9 said:
Papa Charlie. I think you’re correct. I vaguely remember an article or video on how someone made some of these coin shells. I’m thinking that a plaster mold is made of a 50 cent piece by doing multiple thin dips of the coin into thinned plaster so that you have a clear representation of the coin face.... and somehow through the process of plaster molds and silicone molds... finally a die is cast which is now larger. By dipping into plaster.... removing....dipping.....and repeating this process a few times, one ends up with a slightly larger representation plaster mold of the coin. Then the silicone mold is made of this and finally the reverse can be cast using plaster.
You now have a pattern which represents the coin but is large enough for the shell so you can fit the original sized 50 cent piece into it.
As far as the die to stamp your shells....Just needs to be a metal hard enough to form a soft silver alloy. Maybe a silver / lead , Zinc, or tin based alloy in which you can then form your shell. And although cast iron is obviously great for a die... maybe a hard bronze will suffice. No matter what, we are talking about a lot of work.
But I vaguely think that the thin dipping into plaster is what gets you to a 50 cents piece which is a little bigger than the original. As far as exacting metal alloys....just not my forte. But I’m think copper based alloys give you harder metals. Lead and zinc give you softer ones.

Personally, to find out more.... I’d shoot an email to Clicksprings / Ramnsey’s website. Or ask him on one of his videos for maybe pointing you in the right direction. I’m betting he would know how it’s done. That’s one talented guy in my opinion. There’s bound to be something out there somewhere.
All that said....it’s a heck of a lot of work and probably cheaper to just buy one.

Expanded Shell - Half Dollar (Head) - Tango D0001

Expanded Shell Half Dollar (Head) by Tango
www.propdog.co.uk www.propdog.co.uk

not saying it’s cheap. But by the time you tool up and buy your supplies to make one, it’s still more cost affective.
Click to expand...
some people just want to know how to make and you never know i might be the next johnson coin manufacture
 
i have looked into having a die made waiting on reply .would rather make one every 30 min vs one every 5 hours with crap results lol
 
Well...if you want to make it and time and effort isn’t an issue. Then like I say. By dipping a half dollar into a thinned plaster Paris slurry... remove...dry...repeat.... then you’re now making an image for a pattern which is larger than a 50 cent piece. The thinned slurry will run off the 50 cent piece and have a close resemblance of the coin.
Of course there will be some adjustments to the plaster recipe because just letting it quickly dry and it’s going to flake off. But I’m thinking there’s a way of getting there. Maybe making a silicone pattern of the 50 cent piece and then using it as the pattern original and then dipping the silicone in the slurry.

The point being is after a few dips in slurry you now have a close resemblance of the 50 cent piece but it’s larger since each dip increases the size. And you’d need to hold the coin or master silicone pattern with tweezers. Once you get to the right size.... then you will make a pattern of this now larger 50 cent piece to cast your now larger 50 cent piece which will act as you shell. You can cast it in cast iron..... if you are looking for a die.

FWIW.... MyFordBoy on YouTube has tons of high quality backyard casting videos. He’s a expert in my opinion when it comes to casting..

really a highly skilled pattern maker and backyard foundry guy.
 
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I have come to the conclusion im going to have a over sized die made just little bit bigger then original oem coin i will be shipping a ex shell to the die maker problem solved.
 
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