Last week I saw the last Harry Potter movie with my daughter...
Last spring she'd already marked our toaster with the sign of the Deathly Hallows, so why not mark our dog too? As an animal lover, I wouldn't actually MARK our dog - but a dog tag on his collar works great.

I 'hacked' a Chilean 500 peso coin, added some solder and copper wire, stamped the back, cleaned and polished the tag (with my Dremel stylus :-) and now the family dog is wearing the latest in Harry Potter (pet) jewelry.

Here's what I used:
500 Peso coin from Chile (a battered coin leftover from a trip to Chile years ago - you could use any two-tone (bi-metal) coin with a silver outer ring - Canadian two dollar coin, 2 Euro coin etc.)
Lead-free solder
flux
heavy gauge copper wire (or brass - should contrast with center of coin)
heavy-duty soldering iron or regular propane torch
Fire brick or similar for a soldering surface
hammer
bench vise
steel letter stamps (the kind used to mark tools - I got mine at Harbor Freight Tools)
wire cutter
file or coarse sand paper
fine sand paper (from medium to very fine or higher)

optional:
buffing compound and something to use it on (Dremel tool or similar)

As usual, BE SAFE when you use a soldering iron or torch.
Wear a dust mask and safety goggles when sanding, buffing or polishing with motorized tools.

Step 1: Pound Coin Into a Triangular Shape

1. Insert your coin into the bench vise, leave one side sticking out above the jaws. This will be the first side of the triangle. Clamp the vise as TIGHTLY as you can - really lean on the handle.
2. Take your hammer (regular 16 oz. hammer is fine) and pound on the raised part of the coin. Hit down on the coin and slightly pull the hammer towards one end of what will become the side of the triangle. In theory, the glancing blow will help push the metal sideways to form a corner, instead of just mashing the metal down into a mushroom shaped edge. No matter how hard you tighten the vise, the coin will end up getting pushed down between the jaws.
3. Reposition the coin as needed and keep pounding the sides flat. Try to get the metal to 'stay flat', to stay in the plane of the coin so that it remains flat like a sheet of metal. If the side mushroom out, use the flat part of the vise as an anvil and pound the coin flat. The goal is to make a triangle-shaped piece of flat metal.
4. Don't worry when the 'corners' pull away from the center of the coin - you will fill the gap with solder in a later step. (As a side note, take a look at the groove on the edge of the central disc - that's how they keep the bi-metal coins from popping apart during normal use).
5. Stop when you have a pretty good triangle. The corners will still be rounded some, but that is taken care of when we FILE in a later step.

Step 2: Fill Gaps With Solder & File to Refine Shape

1. Clean the pounded coin with vinegar and an old tooth brush. Rinse well and dry it with a clean rag.
2. Preheat soldering iron.
3. Flux the coin, making sure to get flux into the gaps at each corner.
4. Use lead-free solder to fill in the gaps at each corner. I had some trouble getting a complete fill - maybe I didn't clean the metal well enough. I gobbed a ton of solder and figured that I would clean it up later :-)
5. Wash coin in warm, soapy water to remove any flux. Dry well.
6. Use a file or coarse sand paper to refine your triangle shape. I left rounded corners to prevent anyone getting poked by sharp corners.

Note: The solder I used did not quite match the silver-colored metal of the coin... I don't know what to do if this happens to you. I decided to call it a 'feature' (not a bug) and that the color change added a 'shimmer' to the Deathly Hallows and made the triangle look more like the 'invisibility cloak'.

Step 3: Add the Elder Wand

1. Find a piece of wire to use as and elder wand (I used the grounding wire from some romex electrical cabling - I think about 14 ga.). File both ends of the wire nice and flat (and neat).
2. Use a file or coarse sandpaper to clean up both flat sides of the coin. I did not sand away all the details of the coin and I wish I had done a better job of it - it's much harder to get a flat surface after the elder wand is soldered onto the coin.
3. File a shallow groove from one tip, straight down to bisect the bottom edge of the triangle.
4. Apply flux to the groove.
5. Lay wire into the groove.
6. Use small nails or pins to hold the coin and wire in place. (A fire brick is a good soldering surface because it is soft enough to easily hold nails).
7. Solder wire in place. It's tricky to get everything hot enough with a soldering iron, even with my 100 watt iron for stained glass. I ended up hitting the entire mess with a hardware store propane torch (like you use for soldering copper pipes).
8. Use a hammer and pound the wire to flatten it. I thought it looked better, but you can leave it round as you wish.

Step 4: File and Stamp

1. File both faces of the triangle flat.
2. On back side, stamp your pet's name and your phone number or other contact information.
3. You can use a little paint or permanent marker to accentuate the letters.

A couple of hints:
1. For the best letter impression, make sure you have your tag on a HARD surface, preferably steel anvil or bench block.
2. Make sure your letters are oriented BEFORE you stamp them into the metal. Some letter stamps have a line or mark on the side to show orientation - BUT they are not always correct. My number 5 stamp had the line on the wrong side of the stamp. grr.... I filed that line off and cut a new one on the correct side.

err, one last hint: Sometimes it is hard to see which letter a stamp makes - especially for the tiny letter stamps. I did not notice that I used a 'y' instead of a 't' until I downloaded pictures from my camera. His name is Tanner, NOT Yanner!

Step 5: Polish and Finish the Pet Tag

Get some elbow grease ready or get a Dremel tool or buffing wheel.
Use a dust mask and safety goggles for this part:

1. Start with with rough buffing compound (black - the one for 'cleaning'). The first picture shows one side done with black compound and the other just sanded. Wash with soapy water and dry well before going to a finer compound.
2. Next use 'tripoli' or brown buffing compound. Wash and dry.
3. Last, use red jeweler's rouge. Wash and dry.
4. Use a round nose or needle nose plier to bend the top of the elder wand to form a bail (loop) for hanging the pet tag.
5. Attach to pet's collar and go for a walk to show off your buddy's new collar accessory!