Silmoldcast Platinum 20 – Transparent Platinum Silicone for Resin Molds (Shore A 20)

Professional 2-component platinum-cured silicone designed for high-detail, reusable molds for epoxy resin and casting applications.

Silmoldcast Platinum 20 is a transparent, addition-cure (platinum) RTV silicone developed for mold makers who need clean demolding, fine detail reproduction, and long mold life. Its Shore A 20 hardness provides the ideal balance between flexibility and strength, making it suitable for repeated resin casting without tearing.

Who this silicone is for

This product is ideal if you:

• Make epoxy, polyester, or polyurethane resin molds

• Need high detail accuracy (fine textures, sharp edges)

• Want visual control during pouring thanks to its transparent formulation

• Require durable molds for repeated use

This product is NOT recommended if you:

• Need ultra-fast industrial cycle times

• Use sulfur-based clays or incompatible materials
  

Key performance advantages

• Transparent silicone – allows visual inspection of bubbles and fill

• Excellent flowability – fills fine details without excessive air entrapment

• High tear resistance & elasticity – suitable for complex demolding

• Low shrinkage (<0.1%) – dimensional accuracy maintained

• Wide temperature resistance – from -100°C to +250°C

• Platinum-cured system – long service life and chemical stability

Technical specifications (at 23°C)

• Silicone type: Addition-curing (platinum)

• Mixing ratio: 1:1 by weight or volume

• Pot life / working time: approx. 10 minutes

• Demoldable after: 45–60 minutes

• Full cure time: 2–3 hours

• Shore hardness (24h): A 20 ±2

• Viscosity: approx. 1950 mPa·s

• Elongation at break: 625%

• Tear strength: 24.1 kN/m

• Tensile strength: 5.2 MPa

• Detail reproduction accuracy: approx. 2 μm

• Shrinkage: <0.1%

• Color: Transparent milky

• Shelf life: approx. 12 months (sealed, 5–25°C, dry & dark)

Compatible materials & applications

Suitable for molding and casting with:

• Epoxy resins

• Polyester resins

• Polyurethane resins

• Plaster

• Concrete

• Polymer clay

• Soap casting

Common uses include:

• Resin clocks and decorative objects

• Art molds and prototypes

• Detailed craft and design molds

• Reusable low-volume production molds

Mixing & use (important)

1. Weigh Part A and Part B at a 1:1 ratio

2. Mix thoroughly for 2–3 minutes
   (Do not exceed ~250 rpm to avoid air entrapment)

3. Pour slowly into the mold

4. Allow to cure at room temperature

Higher temperatures will significantly reduce cure time.

Safety & handling

• VOC-free, solvent-free

• Odorless, non-flammable, non-corrosive

• pH neutral and skin-safe during normal handling

• Not edible

• Keep out of reach of children

• Avoid contact with eyes

Before you buy

If you’re unsure whether Platinum 20 is the right hardness or silicone type for your project, contact us before ordering. Choosing the correct silicone saves time, money, and material.

Why buy from EltoBert Studio

• Stocked and supported locally

• Used by resin artists and makers
  

Final note (important)

This is a professional silicone, not a toy or beginner shortcut. Used correctly, it delivers clean molds, long life, and consistent results.