Intro: Silver Necklace From US Kennedy Half Dollar
I wanted to make my wife something unique for our anniversary and jewelry is a no-brainer! I've always thought the State Profile Necklaces looked cool, but I wanted something truly unique and special. My wife is from North Carolina so that's where I started. I'm also a coin collector so I have plenty of junk silver Kennedy Half Dollars available. The Kennedy Half Dollar was released in 1964 after the assassination of President John F Kennedy. When minted in 1964 it consisted of 90% Silver. For comparison, Sterling Silver is 92.5% Silver so I was starting off with a pretty good material. The term junk silver refers to coins minted before 1965 that have 90% Silver content but where the commodity value of the Silver holds more value than the numismatic or collectible value of the coin. Whenever using any vintage coin for a project it makes sense to validate it's numismatic value before messing with it. I usually check Coin Trackers online to make sure I don't have a truly rare coin. About this time inevitably someone brings up the legality of defacing currency. Yes, it's illegal to manipulate currency to increase the value and use it for commerce. If you try to add a couple 00's to your $10 bill and spend it at the Piggly Wiggly you will likely get your room and board paid for by the US Taxpayers for about 10 years! Using U.S. currency for jewelry or novelty is not illegal. Here is a link to the U.S. Mint's FAQ on the matter.
One word of caution, coins minted after 1964 contain Nickel. Many people have a sensitivity to Nickel that they may not even realize.
Finding Junk Silver coins used to be quite easy by getting rolls of half-dollars or quarters at the local bank and searching through them, but this source has pretty much dried up in most urban areas. These coins are readily available online however, and from your local coin shop. A good rule of thumb is that $1 face value of coins should cost roughly the same price as 1 oz of Silver on the commodities market. At this writing Silver is between $13-15 dollars per ounce. So 4 pre-1965 quarters, 2 half-dollars or 10 dimes should all cost about $13-15.
Step 1: Getting Started - Layout
With my idea firmly cemented in my mind I went online and found a scalable picture of the NC border and sized it down to fit a US Kennedy Half Dollar (Dia = 30.6mm). I printed the image and cut it out. I then double checked it's circumference against my Half Dollar just to make sure my math and my Paint.Net skills were on target.
To get started, I sprayed both the coin and the template with a 3M spray adhesive I picked up at the local craft store for about $14. The uses for this in the shop or craft room are endless and it lasts a long time.
From there it was a simple process of cutting on the line with a jewelers saw and polishing things up with my cordless Dremel.
Step 2: Cut Out the Shape
In this step it helps to have a couple of specialty items, but they're not absolutely necessary. The first is called a Bench Pin. This is a piece of hardwood that clamps to your bench and provides a stable surface for your work piece. These are cheap and can be bought online for about $7. It's a great investment if you'd like to do much cutting, but you could also use a scrap piece of hardwood and a regular clamp. The other important piece is a Jewelers Saw. Although not absolutely necessary, these are about $12 and are nice to have for precise cutting tasks. A regular scroll saw or coping saw could also be used.
The key to precise cutting is to have good tension and lubrication on the blade. When taut, the blade should ping with a high, clear note when lightly plucked. Readily available lubrication for saw blades can be had in the form of everyday candles, paraffin wax or beeswax.
The process of making precise cuts with a Jewelers saw requires you to have the workpiece about chest high for good sight alignment, keeping the saw blade perpendicular to the workpiece and using a very light touch with smooth, steady strokes. The Silver dust will accumulate on top of the coin obscuring the template lines so it helps to have a can of compressed air handy to blow it off. It's heavier than normal dust so a simple puff of breath doesn't clear it away as easily as say, wood sawdust.
When you initiate the cut, or when cutting long, straight lines it can be easier to angle the blade forward, but for the tiny, precise cuts it's important to keep the blade perpendicular.
If you elect to use a Jewelers Saw, the fine blades break frequently. It's no surprise to snap 3 or 4 of them in a cutting session. This happens a lot when you are first starting, don't get discouraged, there's a reason they sell them by the gross! They're also pretty reasonable, about $5 for a pack of 144 blades. But it can be frustrating to have to keep changing the blades. You can help reduce breakage the following ways:
- Keep the blade tension high - listen for a high, clear ping when plucked
- Keep the blade well lubricated - apply beeswax every 15 seconds or so as you go
- Use a light touch - forcing the blade will make it snap
- Use the right blade for the job
Choosing a blade:
Jewelers Saw Blades have a unique numbering system, the blade thickness decreases and the number of teeth per inch increases from #6 to #1, and then the numbering changes to 1/0, 2/0, 3/0, 4/0, 5/0, 6/0 with 6/0 being very fine. As with any cutting, the rule of thumb is the same, optimum blade size provides for 3 teeth to remain in contact with the section being cut at all times. For cutting coins I prefer a 2/0 or 4/0 if there is a lot of intricate detail. In this project I used 2/0.
Step 3: Finishing
Now that you've effectively got 3 pieces you can reserve the cut-offs to melt down in a future Instructable. These can be very easily melted down with an ordinary propane torch into Silver beads for a ton of uses.
You're left with a chunk of Silver coin that vaguely resembles the coastline and borders of your State. This could be left as is if you're truly a Coin Freak, but if you want a smooth, polished Silver piece there's a little more work.
For the initial smoothing a large file or coarse sandpaper can be used, or simply chuck up a sanding drum to your handy Dremel and grind off the coin's embossing, leaving behind a smooth, clear Silver surface.
Once you've got the surface clear you can finish however you like - a wire brush will create a nice brushed finish, steel wool will leave a matte finish or to go for a high polish you can use increasingly finer abrasives. I actually buy a 3-pack of nail files from my local pharmacy and polish through the 3 grits. Further polishing can be done by hand or with the buffing pad on a Demel and a bit of polish paste such as Mother's Mag and Aluminum Polish available online or locally in the automotive section of any big box store or auto parts store.
Since this is Silver it will tarnish. There are a couple of ways to delay that. Notice I said delay and not prevent. Silver tarnishes via reaction with Oxygen. Unless you're hermetically sealed or tethered outside of the International Space Station, you will encounter Oxygen, thankfully! The first way to delay tarnish is to coat the piece in some form of protectant. There are Jewelers Sealants that could be used, but normal clear nail polish works in a pinch with only slightly less durability. Following that, a light coat and buffing of wax will help protect it further. There are specialized Jewelers Waxes too, but standard automotive paste wax works just fine.
At this point, you're almost finished. To make it a necklace a small 1/16" hole can be drilled anywhere you like and jump rings used to connect it to a chain or leather cord. Jump Rings are quite inexpensive and can be found at any local craft store.
Step 4: Conclusion
Through these steps you've learned some basic Jewelry Making principles - template layout, sawing (called piercing in the Jewelers Community), polishing, sealing and finishing. With these techniques the possibilities are endless to what you can create. Any material can be used and very intricate patterns can be cut with a little practice. Some other examples would include monograms, team logos, religious symbols, etc. Suitable materials can be found everywhere - copper, stainless steel and bronze all make great materials to work with.