Hey! In this Instructable, I will be going through the process of how to cast a metal pendant using pewter and MDF molds. Unfortunately, this project does require access to specialized equipment (see list below), however, once you have your hands on it, there's a great deal of flexibility in design and aesthetic properties. Please feel free to ask any questions you may have in the comment section below :)

Let's get right into it...

Supplies

Low-Temperature Casting System
Drill Press
1.5 mm Drill Bit
Junior Hacksaw
Sandpaper (Micro Grit - FEPA Levels)
- 200
- 400
- 800
- 1500
Laser Cutter
MDF (3 mm thickness)
Pewter
3x M3 Hex Bolts
3x M3 Hex Nuts
Dremel Kit (w/ Polishing Head)
Brasso Polish
Wire Wool
Metal Chain
Small Metal Rings (Steel Fasteners)

Step 1: Designing & File Configuration

The first step of the process is to pick a design/drawing you would like to cast. In this example above, I used the outline of a bird (which I grabbed from the Noun Project). This was done on Adobe Illustrator (file attached below) as the software is relatively easy and straightforward to work with.

The next step is to determine to size. This is contained by 3 factors:

1. Preference of the user.

2. Size of the casting machine - the mold must fit into the casting area.

3. Fluid flow rate - this is particularly important as a mold cannot be so big that the pewter starts to solidify before the mold is completely full. This would lead to multiple malformities in your final product.

Final Notes

Ultimately, three pieces of MDF must be cut. One-piece with the design cut into it, and the other two with solid sides so as to form a full mold. These pieces have to be securely joined later on which is why I included three holes (3 mm) in the corners of each triangle. These holes will allow for bolts to secure the pieces together.

Finally, on the centerpiece, it is important to create a small path from the edge to the design. This will enable the pewter to flow securely into the mold. Ensure that this point is the highest edge on the design to reduce the risk of an incomplete final product.

Bird.ai
Download

Step 2: Laser Cutting

Now it's time to laser cut all the pieces. On Adobe, this meant first preparing the file for cutting by ensuring no design had any fill, all line thicknesses were 0.01 mm, and that all lines were red (for cutting).

Be sure to prep the laser cutting from turning on the exhaust to reduce the risk of fire and toxic gas inhalation. Additionally, make sure the cutting bed is level with the MDF. When cutting, ensure the hood is down and avoid eye contact with the laser.

*Important Note: In the image above, you may see that there are actually 4 pieces instead of three. This is only because I was testing out different sizes of molds. In actuality, you only need three pieces as mentioned in the previous step.

After the cutting is done, remove all pieces with care and lay them out. Examine the MDF version of the design to ensure correct sizing (although this piece can ultimately be thrown out as it is no longer necessary to keep for the following steps)

Step 3: Secure the Mold

Gather 3x M3 Hex Bolts and Hex Nuts. Take the three pieces that have just been cut out and layer them so that the cut out version (design piece) is sandwiched between two normal pieces. Slide the Hex Bolts through each hole and fasten them with Hex Nuts on the other side (though not too tight).

Now take the time to ensure that the mold fits into the casting machine. If not, feel free to saw out the excess ends of each bolt.

Step 4: Casting

It is finally time to cast the Pendant (apologies for the lack of photos in this step)!

The exact specifications of the system I used can be found here. For specific details into the operation of the casting system, there are plenty of very specific videos online that will do a much better job of explaining the process than I ever could. That being said, here are the general steps to follow:

Secure the mold to the removable metal tray and ensure it fits comfortably
Add pewter to the tank above and secure the top
Switch the casting system on and wait 30 minutes for the pewter to completely melt
Slide the tray under the dispenser and ensure it is aligned with the hole in the mold
Start the liquid metal flow by pressing a lever on the side (do this in a controlled manner and stop as soon as the mold is full)
Let the mold cool before moving it and ensure all pewter is solidified (turn off the casting system)
Remove the bolts and remove the casted pendant out of the mold

*Important Safety Considerations - make sure to wear heatproof gloves and protective eyewear throughout this entire process (seek proper supervision is required).

Step 5: Removing Excess Pewter

It is now time to remove the excess pewter caused by the passage we created to allow pewter to fill the inner design. To do this, grab an engineer's vice and clamp the pendant in place. Using a junior hacksaw, carefully and delicately cut the excess off.

Step 6: Sanding

It is now time to remove all impurities from the pendant. This is perhaps the longest part of the process and it definitely takes time so patience is important.

Using wire wool to start will is optional. To begin, take a piece of sandpaper rated at P200 and smooth out the surfaces on the pendant. Make sure to sand in ONLY one direction for aesthetic purposes and be very careful to not make deeper scratches. Wet the sandpaper before beginning and spend a good 20 minutes on each side of the pendant.

Repeat this process with grains P400, P800, and P1500.

Step 7: Polishing

In order to finish the surface, we must polish the pendant using Brasso (other polishers work as well). This can be applied by hand using a cloth, or by Dremel with a polishing drill bit (preferable). If using a Dremel, be very careful not to scratch the pendant in ANY way as it would mean repeating the entire sanding and polishing process (this happened to me, definitely wasn't fun).

Step 8: Drilling

Now that our pendant is pretty much finished, we need to be able to attach it to bracelets/necklaces. To do this, you will need a drill press (please try not to use a hand drill). Use a clamp to secure the pendant in place and a 1.5 mm drill bit to make the necessary holes. I drilled two holes (one in the head and one in the wing) to support the design I used. This is a very very delicate process so proceed with caution.

Step 9: Attaching the Necklace/Bracelet

Finally, I took two small metal rings and fit them to the pendant using pliers. Please be very careful again not to scratch the pendant.

At this point, it is up to you what to do with the Pendant. It may be left as it is, attached to a necklace or even a bracelet. The choice is yours!