Lost wax casting is a method of sculpting or jewelry-making that allows for an extremely accurate, hollow copy of an original wax or clay model to be created with a variety of possible metals. This process is also often used to create a small copy of a much larger sculpture. Lost wax casting dates all the way back to the Chalcolithic Period and is quite complex, involving many different tools used over a specific sequence of events that needs to be precisely executed for the final piece to come out correctly. Here, we breakdown the list of supplies needed for lost-wax casting, followed by an overview of the process.
Lost Wax Casting Supply Kit
The following is a list of the different items needed in order to complete a sculpture or piece of jewelry with the lost wax casting process. Please note that sometimes not every single one of these items is needed for the full process, as certain items can be a matter of choosing what works best for your process. (For example, you can use a respirator mask or dust mask, but would not use both at the same time, etc.):
1. Sprue Base– The sprue base is a rubber piece that the sprues for the sculpture or jewelry are then attached to. The sprue base you choose will be dependent on what type of flask size you utilize.
2. Sprue Flask– The flask is the receptacle for the investment to be poured in that gets lowered over the sculpture or jewelry and attached to the wax.
3. Timer– It’s important to have a reliable timer that also uses seconds since the timing is crucial for each part of the process to work correctly. Kitchen timer works great, no need of a special timer for this purpose.
4. Scale– It is vital to get the measurements of the mixtures you are using right so that the ratios are correct. Therefore, an accurate scale is needed. Depending on the size of the lost wax object, kitchen scale or a bigger one - purpose built is needed.
5. Measuring Cup– This is used for measuring the water in the process. Graduated Cylinder– You can also use a graduated cylinder for measuring the water.
6. Investment– The investment is used to create a hard shell around the sculpture or piece of jewelry. It is created by dipping the wax into a slurry, followed by a sand bath that forms a wall of silica around the wax over time.
7. Scoop– This is another measuring tool in order to avoid touching the various chemicals with your own hands. A big metal scoop works really well.
8. Mixing Bowl– A rubber mixing bowl is a great tool for putting under the vacuum dome to combine the mixture together.
9. Flask Extender– This helps to extend a flask to make it taller or to solidify the top of the flask, especially if the height of your piece extends beyond the height of the flask or if you are worried about the mixture bubbling over.
10. Tape– Tape is helpful to seal the top of the flask so that the investment doesn’t accidentally bubble over the top of the flask. Masking tape or painter’s tape both work well.
11. Vacuum Table– This is a table with a vacuum that removes air from clay or rubber to prevent bubbles in the final product.
12. Centrifugal Casting Machine– This type of casting machine uses centrifugal force and the weight of the metal to fill the mold. It’s usually used to cast small objects like jewelry, collectible figures and so on.
13. Respirator– A respirator mask helps filter out harmful fumes that an artist would otherwise inhale when creating their work. The mask should fit tightly to your face.
14. Dust Mask– A dust mask is another type of protective equipment which helps prevent particles from entering your lungs, such as the silica contained in the investment. If you have a respirator mask, you don’t need a dust mask, since the respirator mask is capable of filtering small particles.
15. Ventilation– Ventilation refers to a system that helps remove chemicals, dust particles, and other pollutants from your workspace. Ventilation is very important for your safety so that you are not breathing in silica and other harmful chemicals and particles that are a part of the lost wax casting process. Consult ventilaion expert to make the best ventilation system for your workshop.
16. Kiln– This is a special oven that reaches incredibly high temperatures to help bake, dry, or burn artwork or pottery.
17. Blowtorch– The blowtorch is the device that uses fuel (either propane or alcohol) and concentrates it at extreme temperatures to help melt metal for various artistic and mechanical purposes.
19. Torch tip– This is just as it sounds: the end point of the torch, which can be changed out in an array of different shapes and sizes based on what works best for your specific piece.
20. Crucible– The container holds molten metal for centrifugal casting or pouring.
21. Flux– This is for prepping the crucible and casting. It helps to promote fusion.
22. Stirring Rod– A carbon stirring rod is necessary to help mix the metal without having the metal end up sticking to the rod itself.
23. Hot mitts– To protect yourself from the extreme temperature of the kiln, blowtorch, metal, etc.
24. Tongs– Tongs help you to hold the very hot tools you are working with without actually touching the hot surfaces themselves. Try using the small end of the tongs for more precise control over what you are holding instead of the large rounded part.
25. Eye protection– Always wear eye protection as a precaution against getting chemicals and dust particles in your eyes. This is usually in the form of some type of protective goggles.
26. Quench Bucket– You’ll want a large bucket that will fully envelop the flask that you need to cool down. Make sure there is a layer of investment on the bottom of any new bucket so as to not melt the bottom.
27. Toothbrush– A toothbrush is a cheap, easy-to-use tool to help get off the extra investment on the piece once it has cooled off.
28. Brass brush– This helps to knock off big chunks of investment from your piece, as well as to clean your flasks. It is used at the end of the lost wax casting process.
29. Pickle– Unfortunately, this does not reference a cucumber soaked in vinegar that you would find at a delicatessen! It is actually a slang term in the sculpting world that refers to the acid used to clean your metal sculpture or jewelry at the end of the process. These can be liquids such as vinegar, pool pH decreaser, citric acid, or sparex.
Lost Wax Casting Process
In the most simplified terms, the process known as lost wax casting is when a wax replica is made, an investment shell is then created around it to form an impression, and then the wax replica is purposefully melted in order for the bronze to take its place in the investment, so that is can eventually solidify into its final form as a sculpture or a piece of jewelry. The melted wax version is therefore destroyed, or literally “lost,” during the process so that the bronze can be molded by the investment.
For a thoroughly detailed explanation of the lost wax casting process, as well as how the tools described above are utilized throughout the process, refer to the article entitled, Cold Casting vs. Lost Wax Casting. Together, this lost wax casting supply list, along with the breakdown of the process itself, should help provide a solid overview of this ancient art form that is alive and well with artists all over the world today.