Somos® WaterShed AF

3D printing investment casting patterns just became easier

Somos® WaterShed AF is a multi-purpose stereolithography resin that meets the requirements for investment casting patterns as it has been designed without antimony to address sensitivities in the casting of certain specialty alloys. This also results in reduced ecological impact, in line with Covestro sustainability goals.

Foundries, service bureaus and other producers of investment casting tooling are looking for affordable, timesaving alternatives to traditional production. From printing to finishing, additive manufacturing offers overall efficiency including cost savings and faster lead times without degrading part properties.

Waiting weeks for metal tooling is no longer needed with 3D printing. Specialized equipment and tooling costs for wax pattern production are also eliminated. Complex and intricate patterns are possible so engineers can optimize the cast for the part rather than for the mold-making process. And the ability to quickly print and test multiple design variations is more easily accomplished versus traditional manufacturing.

By printing on demand, storage of metal tools is avoided. Production on demand also means decreasing transport, shipping costs and -time. Less material is needed as only the material to produce patterns and other applications is used.

Somos® WaterShed AF meets the needs for 3D printing investment casting patterns. As no antimony is used, patterns created with Somos® WaterShed AF leave much lower amounts of ash residue after burnout, reducing clean-up and speeding up mold production. This also reduces the chance of imperfections appearing on the cast part, requiring less rework to finish the part. And it enables investment casting for all types of (high performance) alloys such as nickel-based super alloys and titanium.

The new material is highly dimensionally stable thanks to the its low moisture uptake, so parts maintain their dimensions and mechanical properties, even under varying environmental conditions. This is particularly important in applications with tight tolerances such applications for aerospace and aviation, transportation, energy and utilities. Somos® WaterShed AF can create accurate, complex patterns with excellent surface finish. Its low viscosity makes parts easy to print and easy to clean – typical for all resins in the Somos® WaterShed family. As such, it also fits the needs for general purpose prototyping and other applications. 


  • Investment casting patterns
  • Aerospace and aviation applications
  • Transportation applications
  • Energy and utilities applications
  • Jigs and fixtures/operational aids
  • General purpose prototyping

Product Features

  • No detectable levels of antimony per ICP-AES test methodology
  • Trace amounts of ash that are easily removed
  • Low viscosity
  • Dimensionally stable
  • Suitable for high-end alloy castings
  • Rapid draining
  • Produces accurate, repeatable parts regardless of size                                                                                                                                                                                                                                                   

Learn more about 3D printing investment casting patterns

With the development of new materials especially designed for the investment casting process, foundries can now realize significant savings in time and costs by directly printing patterns and eliminate the need for metal tooling altogether. 

How can we help?

Get in touch with our experts to discuss how Covestro can help you tap into the full potential of additive manufacturing.