390 Silicone Rubber

From: £26.46

Grade 390 is the stiffest grade of Sylmasta Silicone Moulding Rubber with its high dimensional stability making it ideal for larger moulds

SKU: 390


Grade 390 is the stiff grade of Sylmasta high tear strength moulding rubber for producing moulds used in the casting of polyurethane resins.

When cured, the stiffness of Grade 390 gives it the highest dimensional stability available, making it ideal for larger moulds.

Sylmasta Moulding Rubbers are produced to the highest standards for use in industry and model making to produce flexible, highly detailed rubber moulds of all sizes.

The high-quality of Sylmasta silicone rubbers means that once a mould has been taken from the master, it can be used again and again to pour multiple castings using Sylmasta PU Casting Resins.

Moulds made from Sylmasta Moulding Rubber have low shrinkage with no distortion and good dimensional stability. The long pot life means that there is plenty of time to pour the rubber and allow air bubbles to disperse.

Each pack of 390 Silicone Rubber contains catalyst and comes with a free reusable pipette, mixing cup and stirrer. You can order additional accessories from our Casting & Mould Making Accessories section.

If you wish to make moulds for use with Sylmasta CPU31 ClearCast Resin, then please use Grade 400.

Sylmasta casting resins have been trusted by professional kit builders and industrial users for years for their high detail and repeatability.

390 Silicone Stiff Moulding Rubber details:

  • Pot Life: 45-120 minutes
  • De-mould time: 8 hours
  • Mixed viscosity: 19,500 mPa-s
  • Shore A hardness: 22°
  • Elongation at break: 497%
  • Tensile strength: 3.64 mPa
  • Tear strength: 26.24 kN/m
  • Young’s modulus: 1.5 mPa
  • Linear shrinkage: 0.4% min.
  • Service temperature: -50°C max.
  • Service temperature: 200°C
  • Colour when mixed: Pale blue

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