Pewter Skeleton Key Talisman

I have always been interested in casting metals, but has always seemed daunting and expensive to do. While researching low-melting temperature metals, I found information about casting pewter into MDF molds and so I thought it would be fun to give it a try.

Step 1: Materials and Tools

Materials:

MDF Scraps
Pewter Ingot (Make sure you use NON-LEAD pewter!)
Black Pewter Patina
Latex Gloves
Plastic Cup
Silver link or wire
Fine Steel Wool or Buffing Wheel
Paper Towel
Chain or String

Tools:

Hot Pot, or Crucible and Torch
Safety Gear (Face shield, leather gloves)
Wood Carving Tools (CNC, Rotary Tools, Mill, Knives, etc)
Drill 

Step 2: Design

I was inspired by some antique skeleton keys that I found in a shop of Curio on a trip to Chicago last fall. I tried to keep the design fairly simple, so that the details wouldn't be lost in the casting. The design was drawn in Adobe Illustrator. Here is my design if you would like to use it for your own casting, please use it for non-commercial purposes only. Thanks! 

https://dl.dropboxusercontent.com/u/101806676/Skeleton_Key.pdf

Step 3: Making the Mold

I used a CNC machine to cut out my design in MDF. In the first attempt, the impression was too shallow, so I ended up using a scrap of 1/4" MDF to cut out a profile that was slightly larger than the original design and sandwiched the two pieces together. 

Step 4: Casting Pewter

I found an all-in-one unit online called the Hot Pot 2 that works great for melting the pewter. Place the ingot in the pot and wait for it to melt completely.

A few safety notes: I have read online that it is a good idea to have your mold on top of sand in case the liquid pewter spills, it can catch it and not react in a violent way. Apparently, the molten pewter must not come in contact with anything with moisture in it, or it can explode, potentially causing injury. So be careful! Also, please make sure that your pewter is lead-free, as the fumes could be very toxic. It is definitely is a good idea to wear a face shield and leather gloves as well. 

Pour the molten pewter carefully into the mold and let it cool completely before removing it. Clean the piece with fine steel wool and scrub with soap and water.

Step 5: Metal Finishing

Next, to achieve an "antique" finish, a patina can be used to blacken the metal.

Another safety note: Be very careful with the Pewter Black, as it contains potent acids that can be fatal if misused. Wear protective gloves and eye-wear to avoid injury. This part is probably best to do outdoors if possible. Please check out the warnings on the label.

Place the pewter into a plastic cup and pour the patina onto it. Only a small amount is needed and you will notice it turn black quickly. Remove from the solution, being careful not to get any on your skin and rinse with water. Pat dry with a paper towel and allow to air dry completely. Then, either using the steel wool or a buffing wheel, polish parts of the pewter to expose the shiny metal and leave parts of it black to your personal taste. Looking good!

Step 6: Mounting

Drill a small hole at the top of the piece to the size of your silver link or wire. Loop it through the hole and squeeze it together to form your bail. Attach your chain or string and you are finished!

Step 7: Conclusion

Now wear your talisman to protect you from demons, use it to lead a séance, or convince people that it's made of rare, precious metals and pawn it for loads of cash! I hope you enjoyed this Instructable, thank you for reading!

Comments

[dchev]

What happened on the key area? There's some holes that weren't on the mould. Did that happen from moisture in the wood or a gas pocket when pouring the pewter? Looks awesome anyway. Was just curious about that part before I try it myself.

[purpletheory]

I'm not really sure what caused the bubbles, I would like to experiment with drilling a sprue on top of the mold and having it completely encased when pouring the metal in, that might limit the bubbling.

[ablackthorne]

If you take a slender steel rod you can run it around all the areas of
the mould while the metal is still molten, to get rid of any voids. If
you ever decide to use silver make sure it Argetium Silver to prevent
the same sort of issues, except with silver it's caused by oxidation.

[purpletheory]

Thanks for your comment, it's certainly not my intention to propagate bull;-) It is good to know that a typical hobbyist (like myself) would not possess the means to heat lead to temperatures high enough to produce toxic fumes, but the main idea that I am trying to emphasize is to not use lead at all. Maybe I am being paranoid, but I prefer to err on the side of caution, lead jewelry seems like a bad idea. Most of all, I would really hate for someone to be injured following something that I wrote. I really do appreciate all the good information and advice though, that's good to know about the dangers of heating zinc!
Cheers

[jimjimbobim]

What knid of CNC machine do you use?

[purpletheory]

Is a CNC Shark Pro from Rockler

[Mrballeng]

This is fantastic! Great work.

[purpletheory]

Thanks for the kind words, I should take some lessons from you, your jewelry is great!

[Very Interesting]

Impressive! Nice job :)

[purpletheory]

Thank you!