Polytek Poly 74-30 Liquid Rubber is a two - part liquid polyurethane system. It cures to an amber (color may vary) Shore A30 rubber. This pourable rubber can be easily thickened with PolyFiber II Thickener for brush - on use. If you prefer a transparent, amber version, check out Poly 74 - 30 Clear Liquid Rubber. For a high - tear option, consider Poly 74 - 30 HT Liquid Rubber. Before using, shake or stir Part B. The color of polyurethane Part B might change from batch to batch or darken over time, but it won't affect product performance. For more physical property details, refer to the Physical Properties Bulletin. Technical specs include a 1A:1B mix ratio by weight, Shore Hardness of A30, a 25 - 30 min pour time, 16 hr demold time, an amber (varying) cured color, 2,000 cP mixed viscosity, 27.5 in³/lb specific volume, 1.01 specific gravity, 506% elongation, 281 psi tensile strength, and 62 pli Die C Tear Strength. If the provided links for product literature don't work, visit the manufacturer website https://polytek.com/ and use their material calculator. You can find the Poly 74 - Series Technical Bulletin, Safety Data Sheet for Part A, and Safety Data Sheet for Part B there.

Using the Polytek Poly 74 - 30 Liquid Rubber Kit is straightforward. First, make sure to shake or stir Part B well before use. Mix Part A and Part B in a 1:1 ratio by weight. Once mixed, you have about 25 - 30 minutes to pour the rubber into your mold. If you want to apply it by brush, add PolyFiber II Thickener to thicken the rubber. After pouring, wait for 16 hours before demolding. You'll get an amber - colored rubber (the exact color may vary). The color of Part B might change from batch to batch or darken as it ages, but don't worry, this won't affect how well the rubber works. Keep the rubber in a cool, dry place. If you need more details about its physical properties, check the Physical Properties Bulletin on the manufacturer's website. If any of the provided links for product literature don't work, just go directly to https://polytek.com/ and use their material calculator.