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Hydrocal® Medium High Expansion Cement

Key Documents & Design Files


Expands uniformly in all directions; has the highest setting expansion of any gypsum cement.
Designed for fabricating patterns, matchplates and models with a shrink allowance.

Main Features

Hydrocal® Medium High Expansion Cement is a specialized expansion plaster used for fabricating expanded patterns and models. Used by a range of industries, including aircraft, automotive, foundry and plastics, USG Hydrocal® Medium High Expansion Cement:
  • Offers uniform expansion in all directions and the highest setting expansion of any gypsum cement (expansion is controllable by the quantity of water in the mix)
  • Facilitates industrial tooling and pattern making; is a standard material in many shops
  • Results in an expansion value from 1/16-3/16 inch per foot with the proper water-to-plaster ratio, and is usually obtained within two to three hours after the initial set
  • Provides dimensionally stable patterns for three to four days after the desired expansion is achieved
  • Requires 44-50 parts water by weight per 100 parts plaster

Documents & Files

Catalogs & Brochures

Brochure (English) PDF 613.4 KB

Installation & Technical Manuals

Installation Guide (English)

SDS, Certifications & Reports

SDS (English) PDF 91.1 KB

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Question Guidlines

  • Questions should relate to this product specifically.
  • For help with pricing, availability, or delivery, please call 800.874.4968 (Monday–Friday, 7am–6pm Central)
  • All questions and answers follow USG’s Terms & Conditions.
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q & a

  • Can I color/tint plaster casts?

    Yes. For uniform coloring, colorants can be added to the mix water and should be blended thoroughly. For varied color effects, colorants can be added to the slurry.

    Both mineral colorants and water dispersed colorants are compatible with our plaster products.

  • Have a question?

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  • Need help right away?

    Call our Technical Support team at 800-874-4968 (Monday-Friday, 7am-6pm Central).