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P525 PlatSil Silicone

  • $35.00

P-525 is a platinum-cured, room temperature curing (RTV), silicone rubber designed for the manufacture of high-performing, flexible molds. This two-part (Catalyst & Base), liquid silicone rubber has a Shore Hardness of A25, a pour time of ~15 minutes, and a demold time of ~4 hours.

P-525 molds are commonly used to cast the following materials:

  • Urethane (polyurethane) plastic and rubber
  • Plaster
  • Polyester Casting Resin
  • Cement, Concrete
  • Epoxy
  • Soap
  • Wax
  • Low-Melt Metals


Release agent is not necessary for casting most materials into P-500 Series molds, but for longer mold life with epoxy, polyurethane or polyester resins, a barrier coat or release agent (SupraLease PTR) is recommended.

This is a pourable rubber, but it can be easily thickened with silicone thickener for brush-on application.


Physical Properties

Type Platinum-cured (addition-cure)
Mix Ratio by Weight 1 Part Catalyst : 1 Part Base
Shore Hardness A25
Pot Life 15 min.
Demold Time @ 77°F 4 hr.
Cured Color Blue
Mixed Viscosity 3,400 cP
Specific Volume 24.7 in³/lb
Specific Gravity 1.12
Tensile Strength 485 psi
Elongation 440 %
Die B Tear Strength 165 pli
Die T Tear Strength 39 pli


CURE INHIBITION: Contamination from amines, sulfur, tin compounds, polyester resins, some paints and some silicone rubbers may inhibit surface cure of this product. Perform a test cure on an identical surface to determine that complete curing and good release are obtained.

Product Literature

Technical Bulletin: Magikmold® P-500 Series Technical Data Sheet

Safety Data Sheet: Magikmold® P-525 Catalyst & Base

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