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Thread: Pearl Ring Cast 1888 US Dollar Coin Silver Beginner Sanity Check

  1. #1
    Join Date
    Feb 2017

    Default Pearl Ring Cast 1888 US Dollar Coin Silver Beginner Sanity Check

    Hi all,

    I personally hate it when beginners ask vague questions on a forum and expect others to do all the work for them, however, I also know that a huge text over-explaining my issue may turn some people off, so I have a short version and an extended version of my dilemma(s):

    Short Version
    I am very new at all of this and don't know if there are any a huge flaws in my plan. I would like to cast a pearl ring. Metal is from 1888 Morgan US Dollar (90% Silver 10% Copper). Based on my design, I'm thinking there will have to be some level of machining after casting. Most of the processes I'm considering involve casting a solid cylinder on top of the ring, milling/drilling out a hole from the inside/center of the ring up into the cylinder, setting the pearl up into the hole in the cylinder, and then riveting a plug in to keep the pearl in place. See below for drawings & specifics.

    I'd like a nod of approval from veterans before attempting any of this. I have no idea if there are massive problems with my plan. I also welcome any and all suggestions and answers to questions below, and even any answers to questions I didn't ask but should have.

    Long Version

    My Skills:
    For most intents & purposes, I have no real experience making jewelry. As the son of an engineer and nephew of a machinist, I'm fairly handy and somewhat familiar with what it takes to design and work with metal. I also have a lot of tools at my disposal, but not necessarily tools that are strictly intended for what I plan on doing.

    Small Backstory:
    Around 8 months ago, I bit into a pearl while eating a raw oyster across the table from my girlfriend. We ended up paying our bill and leaving the restaurant without the pearl. Upon discovering the rarity of finding a natural pearl, we both began to stew with regret. She called the restaurant, nobody had found it. Without telling my gf, I decided to go and look for the pearl myself. I found the pearl on the ground below the table. My girlfriend still doesn't know I ever went back and she thinks the pearl is lost forever. Even 8 months later, she still talks about how sad it is that we lost it. At one point, we even discussed how, if I had made her a ring out of it, it would be her favorite piece of jewelry.

    The Pearl:
    The pearl is small (around 2mm at it's widest) and fairly oblong/not spherical. The coloration looks decent to a laymen. I don't have a pic at this time but if you guys think you'd like one I can upload one later.

    The Metal:
    We were both born in 1988, and we both recently made fantastic memories together in New Orleans on a vacation. I would like to use the silver from one or two 1888 New Orleans Minted Morgan US Dollar Coins. Per Wikipedia, it looks to me like this coin is: 90% Silver 10% Copper

    The Design & Plan:
    A few months back I read a bit about different types of casting and I tried to develop my design within the limits of casting in general, and more specifically, within casting methods which would allow me to keep my wax. I remember making a realization that the design I'm about to present to you had a problem and would not cast well, but I cannot remember what my concern was and It may have been unfounded.

    Before I start to explain my process ideas, here are some pics of the design to help you visualize:

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    My design has the pearl set in a sort of cage with three bars. I have several different techniques Im considering. Most involve casting first and some machining on the ring after. I think there is a fairly high chance of me failing the first time during casting so If possible, I'd like to not lose my original wax during the casting process.

    I think I would like to cast the general shape of the ring with the cage setting being cast as solid. Then Id like to mill/drill a hole up into the cage setting from the bottom/center of the ring.

    Click image for larger version. 

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    In the above picture, the orange represents the pearl, the green is a plug holding the pearl in place (also putting slight pressure on the pearl, so as to prevent movement. The purple is a rivet holding the plug in place.

    When it comes to the cutout/scoops in the setting/cage, the ones which reveal the pearl, Im not sure whether it would be better to mill or cast them. If I mill them, the wax blank would then be pretty simple (Wax Style A) and I could maybe consider a lost wax casting method. If I cast them I may be able to scoop the wax more precisely than the silver and end up with a better result (Wax Style B). Its also possible that milling would be more precise and give a better result. There may be other strengths/weaknesses Im forgetting or unaware of.

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    One of the biggest problems with what I have presented so far is that with a complete circle ring, I cannot come up from below with a drill because the bottom of the ring is in the way. There are several ideas I have for how I could work around this problem and still do the milling & drilling, but I'm not sure any of them work well because: I cannot expose the pearl to heat, I'd like to cast a full circle ring without a break, etc.

    Tools Available:
    Milling Machine w/round table attachment for spinning piece , Oxy acetylene torch, probably a propane torch, hand/wood carving tools, pretty much any other basic machine shop tools

    Id like to finish this project before July 13th 2017.

    Challenges & Questions:
    A) Do you all see any major problems with any of what I have told you? Are there flaws with my process, design, or anything else?

    B) Is the Metal suitable for my intentions?

    C) What sort temperature do I need to achieve to melt this metal? Would an Oxy Acetylene torch be suitable? Or maybe just a propane torch? What kind of crucible?

    D) Do you think this kind of setting will secure the pearl enough that it will not move around and therefore will not deteriorate over time? Or is it likely to be too lose and prone to scratching/depreciation?

    E) Is there anyone specific I should contact for help, or any other forums or places on line youd suggest asking?

    I thought a lot about this project a few months ago and have since forgotten some of my ideas. I will update this thread with anything that comes back to me or anything else I think of.

    Thanks in advance for any and all help.


  2. #2
    Join Date
    Jul 2009


    Apologies for this going into the moderated posts - no idea why the system chose your post, but I've cleared it.

    Immediate comment on your design: The top corners of the cage are going to be sharp in use, catching on everything going (including skin). I'd be inclined to radius them to make them a bit safer. The cage should give the pearl plenty of protection, but I'd want to try and fit it as closely to the pearl as possible - the easiest way to do this would be to do the ring & setting separately and then the inside of the setting can be carved (micromotor would be my weapon of choice) to fit (easiest while it's still a wax). It'd also allow for cleaning up the inside of the setting post-casting... The would then need joining back onto the shank post-casting - given it'd have the pearl inside it, I'd laser weld it on (ask around jewellers - or jewelers near you).

    As far as the casting goes - propane will melt it, but oxy-fuel will be faster. 90% silver should be fine if you're set on only using the coins. Crucibles - an open scorifier rather than a traditional cupped crucible is easier with flame melting. What are you casting into? Sand casting needs a lot more metal for the hydrostatic pressure, so has massive sprues in comparison with vacuum or centrifugal casting. Do you have a kiln for burnout? Would outsourcing the casting process be wise, or are you wedded to the idea of casting it yourself too?

  3. #3
    Join Date
    Dec 2009
    Central London


    The main problem I see, is that the pearl which is a delicate thing, will be visually overwhelmed by your engineered mount.

    After all, it is intended as a gift for a woman, not an embellishment for a motor car.

    As such, I would construct a basic ring, with an unobtrusive mount, solder on some wires as claws, or even just glue the pearl into a protective hollow shape.

    Some intensive browsing of rings online will give you more jewellery-like ideas.

    My example below shows an example for mounting and protecting a fragment of irregular safety glass. Dennis.
    Attached Thumbnails Attached Thumbnails sg Safety Glass Ring.jpg  

  4. #4
    Join Date
    Sep 2011


    I think it is a very over complicated way to get around setting the pearl. far easier to get it half drilled and set it on a post - secure and you will be able to see it as well. Pearls are moderately tough, though you should not think about wearing a pearl ring every day. No dish washing etc.
    That being said, congratulations on retrieving the pearl and planning such a gift.
    Make sure whoever drills it has the proper kit and skills.
    Last edited by pearlescence; 14-04-2017 at 06:58 PM.
    instagram: pearlescenceltd1

  5. #5
    Join Date
    Mar 2011
    Manchester UK


    I like the design I would cast the ring and head separate but put holes in the shank that are countersunk underneath then have locating pins on the head that can be riveted over once the pearl is inside. It would also be easier to clean and polish in 2 parts aswell

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    Last edited by josef1; 14-04-2017 at 09:07 PM.

  6. #6
    Join Date
    Aug 2009


    I like that method Josef. The only thing I would change is having less weight in the head, so that the pearl is more visible.

  7. #7
    Join Date
    Feb 2017


    Thanks everyone for the suggestions. Keep 'em coming.

    No worries about the moderation. I'm new enough that I assumed that was normal & took no offense.

    The sharp corners are something I thought of in the past. I think my plan is to cast 'em sharp and add a radius as necessary since it'll be easier to remove than add. Also, if I follow josef1's design, which I think I may, corners & a flat top will help support the cage during the riveting process.

    I too think it's important to have the cage snug against the pearl as close as possible. I had been thinking about different ways to achieve this, and one way I considered is using the pearl itself, or maybe a cast replica of the pearl, to leave an impression in wax. Possibly through heating the wax, pearl, both, or if necessary, casting a copy of the pearl and heating that up, and then pressing it into the wax. I don't know if anyone's done this sort of thing, but I do know that it's not safe to expose pearls to too much heat.

    Laser welding is not something I had considered but could suit this project very well depending on where I go with it.

    Thank you for the heating/torch & crucible/scorifier info.

    I haven't yet decided what to cast into. I don't have access to a proper vacuum or centrifugal casting on my own, though, I could possibly try to create something that would expose my mold to some g force to increase the pressure. Whether it's simply allowing the mold to freefall/drop and then stopping it quickly or swinging like a lacrosse stick or glass blowing. I also do not have a kiln for burnout. I would definitely like to do the casting process myself if I can, and I'm willing to put in some considerable work & time to make this happen. This is a part of the project I need to learn more about and make some decisions on. I do know that this project is important enough to me that if I have to buy two coins and waste some silver I'm willing. I'm not likely to make much jewelry in my life so bad habits aren't as much of a concern to me as they should be for those who do this kind of thing every day.

    Thank you for your stylistic suggestions. What you're suggesting would probably be much easier to make and more appropriate for women as a whole, however, I think my particular woman would like my design better. I also think it would mean much more to me, and therefore to her, if I make this project appropriately ambitious. Soldering some wires around a pearl isn't something I'd brag to my grand kids about, but casting with 130 year old coins and a torch in my backyard is.

    I too think my design is over-complicated as compared to the average pearl ring, however, our relationship with this pearl is also over-complicated as compared to our relationship with the average pearl. This pearl is very important to us. I have designed my ring with the philosophy that it's foremost purpose is to protect the pearl, and secondarily to present it to those willing/lucky to look closely enough. This is not intended to be the kind of ring that makes the the passer-by jealous at a glance, it's intention is to make her heart skip a beat whenever she really looks at it and remembers how much I love her and how lucky we both are. As normal as it may seem to you, I would never consider drilling this pearl, and I'm going to do everything I can to avoid gluing it as well, unless I'm convinced gluing it is the only way to stop it moving around & wearing out over time (see tight/sung fit discussion with ps_bond above & question C below).

    I think there is a very good chance She will want to wear it every day, and I know this is not recommended by the experts. This is also one of the reasons I've overdone the setting. I have done a bit of research on pearl care but I may need some more of your expertise before this project is through. This gift will definitely include a document of fine print instructing her on do's & don’ts and pearl care.

    My man. I very much like your suggestions and I think that's the direction I may go. At one point I had a similar design which had cast posts sticking up from the shank, and a separate flat 'Y' shaped roof above the pearl which the posts would go through & which would be riveted on by deforming the posts. Your design is substantially better. Thank you.

    I will likely need to follow ps_bond's suggestions and round out the corners a bit to keep this ring safe and keep the scratches and clothing snags to a minimum, however, like in my response to pearlescence, the ring's priority to protect the pearl is substantially more important to me than the pearl's visibility.

    New Questions:

    A) Anybody have good ideas on how to get her ring size without causing her mom any false-engagement-alarms?

    B) How concerned should I be about damaging the pearl with pressure when sandwiching it between the two pieces in josef1's design? I don't think I need to have a lot of pressure on the pearl, but I wonder of years of pressure may cause problems over time.

    C) What do you guys think about what I mentioned above to ps_bond about pressing the exact pearl's shape into wax for the casting blank so that the pearl has a snug fit in it's setting? Would it be dangerous to heat the pearl itself to the temperature needed to press it into wax? Would heating the wax only be enough? Would exposing the pearl's surface to soft wax damage the pearl? Any other concerns I'm not thinking of?

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