How to Cold Cast with a 3D Printer

Cold Casting with 3D Printer

Cold Cast with 3D Printed Mold

There are two ways to create custom objects out of metal with a 3D printer. The first option is to print the object directly with a special 3D filament that contains metallic powders such as bronze or stainless steel suspended in a matrix of plastic material. This option works great for users who do not mind the printing time or the post processing cleanup that such pieces usually require. 3D printed objects often have artifacts and granulation that need to be cleaned up when the object is done printing. This is fairly easy with plastic filaments where artifacts can simply be chipped away, or where granulation can easily be  smoothed by chemical or physical processes. Metallic filaments, on the other hand, require a little more elbow grease to clean up because the ingredients in the filament are simply more resilient.

That’s where cold casting comes in. Cold casting allows the user to pour a mixture of resin and metal powders into a mold to produce an object that requires virtually no post-processing treatment. The reason why it is called cold casting is that, unlike traditional metalworking, cold casting requires no heat to pour liquid metal into a mold. Cold casting employs reactive polymers to produces objects with some metallic properties such as weight and magnetism. But, unlike pure metal casts, cold casted objects usually lack the strength and temperature resistance of traditional metal casts. One benefit of this process is that it allows the user to create a master product that can be precisely duplicated multiple times without taking up valuable printing time. The user only needs to print and refine one perfect object which can then be used to create a silicone mold. Read on if you are interested in learning how to cold cast with your 3D printer.

Cold Casting with 3D Printer

Instructions for Cold Casting with a 3D Printer

Before you Cold Cast:

  • 3D Printed Part
  • Mixing Cups
  • Polyester Resin
  • Polyester Resin Catalyst
  • Metal Powder (iron, bronze, copper, etc.)
  • Mold Release
  • Silicone (Pinkysil shown in video)
  • Mixing Sticks
  • Glue Gun
  • Mold Container
  • Clean Flat Surface


  • Take Mold Container and affix to Clean Flat surface with the Glue Gun at the base so that Silicone will not leak out the bottom of the mold when poured.
  • On the base of the 3D Printed Part that will be fixed to the Clean Flat Surface, place a bead of glue from the Hot Glue Gun. This will keep the part in place when the silicone is poured over it later.
  • Mix enough Silicone together to cover the entire 3D Printed Part. Pinkysil mixes at a ration of 1:1. Mix the Silicone thoroughly with Mixing Stick. Mixing will cause the silicone to begin the curing/setting process.
  • Slowly pour the silicone over the 3D Printed Object in an even layer in order to minimize the likelihood of trapping air bubbles in the silicone.
  • Remove the mold from the container when the silicone has finished hardening. Most silicone products take anywhere from 30 minutes to 1 hour to harden depending upon the brand.
  • Viola! Your new silicone mold is born!

 Cold Casting with 3D Printer

Cold Casting:

  • Begin the casting process by thoroughly coating the mold cavity with mold release spray. This will prevent the casting material from damaging the mold when removing the final object.
  • Take the metal powder and gently sprinkle a thin layer to form an anti-stick shell while you prepare to mix powder/resin suspension.
  • Mix metal powder with clear polyester resin in a 1:1 ratio. Stir the mixture thoroughly to ensure uniformity.
  • Following the manufacturer’s instructions, add catalyst to the powder/resin suspension to start the curing process.
  • Gently flex the edges of the mold around the object to break the bond and remove the casted object.
  • Viola! You have a cold casted object!

 Finishing Options:

  1. Gently buff the exterior of your cold casted object with steel wool to produce a metallic sheen.
  2. For an aged look you may apply rust accelerant or soak the object in salted water to produce a oxidized patina.
  3. Combining techniques can produce a unique finish.





Airwolf 3D is committed to designing and manufacturing high-performance consumables, accessories and 3D printers that are fast, affordable, durable and easy to use. All Airwolf 3D printers are made in America; manufactured in the company’s 12,000 sq. ft. facility in Costa Mesa, Calif.  Airwolf 3D printers can be found in Fortune 500 companies, engineering firms, government agencies and schools worldwide. For more information visit, telephone (949) 478-2933, email, or visit the company’s showroom at 130 McCormick, Suite 105, Costa Mesa, CA 92626 for a free demonstration.