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Sil-Craft 820

Mold Making Platinum Liquid Silicone Rubber

Mold Making Platinum Liquid Silicone Rubber

Regular price $429.90 USD
Regular price Sale price $429.90 USD
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Sil-Craft 820 is a two-part platinum liquid silicone with low viscosity, high tear strength, and excellent durability.

Sil-Craft 820 is a soft (shore A-20), platinum cure liquid silicone that has excellent flow properties, allowing it to reproduce fine details of the original master accurately.

Molds are highly flexible and elastic, making it easy to remove the original model without damaging the mold or the casting.


Sil-Craft 820 is ideal for casting the following materials: 

  • Wax
  • Resin
  • Concrete
  • Gypsum
  • Plaster
  • Soap
  • Platinum Silicone Rubber...and more 

Sil-Craft 820 is very durable, ensuring that each mold yields the maximum number of castings. By using a mold release, you can significantly extend the life of your molds.

Additional Effects

Sil-Craft 820 is translucent but can easily be pigmented to create a number of special effects, or brushed on to your mold by adding a few drops of thickener.

Handling Recommendations

Working (mixing) time is a comfortable 30-40 minutes, and the mix ratio is 1:1 by weight, so please have a gram scale ready. Vacuum degassing the material before pouring is required. Demold time is 3-4 hours. 

Sil-Craft 820 is heat resistant up to 400°F (204°C). Post curing with heat (optional) will decrease curing time and enhance the mechanical properties of the silicone.

Get a Sample

Find out how Sil-Craft 820 looks and feels before you start your project. To get a cured sample of our mold making silicone, choose the "Cured Sample" option from the Products menu above. You'll only need to cover the shipping and handling fee of $9.95.

Detailed Guidelines

Technical Details

Sil-Craft 820 Technical Specifications Chart


Sil-Craft Platinum Liquid Silicone comes in either a cured sample (200 grams), 2k (4.4lbs Trial) or 10kg (22lbs) package.

  • Cured samples are 200 grams each and come in the form of a puck or a disk, large enough for you to examine both the flexibility and hardness of the material.
  • The 2k package (Trial) includes 1 kilogram of Part A and 1 kilogram Part B, for a total of 2 kilograms (about 4.4 pounds). 
  • The 10k package includes 5 kilograms of Part A (white drum in photo) and 5 kilograms Part B (blue drum), for a total of 10 kilograms (about 22 pounds).

Shipping & Handling

Free shipping on orders within the continental USA.

  • Samples are shipped via economy USPS and arrive in 5-8 days.
  • 2kg Trial Kits are shipped via international air freight and arrive in 5-8 days.
  • 10kg packages are shipped domestic economy and arrive in 5-8 days, but expedited shipping is available for an additional cost.
  • Multiple shipping methods are available for international orders.

Returns & Refunds

Returns are accepted under the following conditions:

  1. The request to return material is made within 30 days of original invoice date.
  2. The material has not been opened and is in original packaging.
  3. The material has at least 50% shelf life remaining.

Important: all returns are subject to a 20% restocking fee.

Click here to view our full refund policy & instructions.

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