The Eurosil 28 Green is an good alternative to the Eurosil 22 blue. The Eurosil 28 green is RTV cured silicone with a Shore A 28 which is slightly higher than the Eurosil 22 Blue. An ideal strong rubber for making moulds and models or other applications with higher Shore A hardness (mid range).
Packaging: Set 2 kg, Set 10 kg, Set 400 kg
Hardness (Shore A): 28
Working Time (min): 10-12
Mix Ratio: 1A:1B (by weight)
Total Cure (hr): 1
Viscosity (cP): 3.500 (±400)
Tear Strength (N/mm2): 4 ±0.6
Tensile Strength (N/mm2): 9 (±1)
Type product: Platinum silicones (addition-cure)
The Eurosil silicone casting materials are addition silicones that cure on a platinum basis. These two component (A+B) silicones are available in soft to medium hard silicones, which after mixing both parts at room temperature (RTV) harden into flexible, very strong, silicone molding rubbers. The Eurosil silicones are easy to process and durable rubbers. These rubbers are used for making silicone products, but also molds that are easy to release for making molds for casting plaster products, wax and resin materials such as various polyurethane and epoxy materials. A number of rubbers from the Eurosil range can also be used for making concrete moulds. The Eurosil silicones start with Shore A 4 up to and including Shore A 60.
Good preparation helps to achieve the desired quality and often ensures trouble-free casting. Preparation includes preparing both components, mixing tools, scales or measuring cups, controlling the temperature, and ensuring that pouring can be done immediately. But also use the right method, release agents and sealers,
Porous models, such as wood, plaster, stone, pottery or masonry must be sealed with a sealer, because these pores suck the rubber full. We have a special pore sealer that can close these pores with a very thin film layer. Otherwise, you can also use several layers of dried wax paste that must be polished afterwards. This will seal most surfaces. Pottery soap can be used as a sealer for plaster. Lacquer, paint, PVA and Pol-Ease® 2350 Release Agent also work well as sealers for many surfaces. The properly sealed model should then be coated with a release agent (eg Pol-Ease® 2300 Release or release agent VL). Alternatively, PolyCoat, a sealer and semi-permanent release agent, can be used on most porous or non-porous models. Porous models must be ventilated from below to prevent air from forming bubbles in the rubber. To do this, make a hole in the bottom plate so that these models can breathe in it. Models made of sulfur-containing modeling clay (eg Roma Plastilina) must be sealed with shellac. We always recommend doing a test before you start your project! This way you know more about possible adhesion, release, possible inhibition and compatibility between the materials.
Ensure parts A and B are at room temperature before use, the casting chamber is at room temperature and all tools are ready. Surface and air temperatures must be above 15c/60°F during application and throughout the curing period. We advise to keep room temperature of 25°C and this is what our processing times and curing times are based on. The lower the temperature, the thicker the material and the longer the processing and curing takes, the higher the temperature, the faster the curing and processing and the lower the viscosity.
Check the mixing ratio before you start. Weigh Part B into a clean metal or plastic mixing cup, then weigh the appropriate amount of Part A into the same container. Mix thoroughly. Mixing manually with a mixing spatula (Poly Paddle) is best to avoid mixing air into the rubber. Scrape the sides and bottom several times while mixing to ensure thorough mixing. Pour the rubber as soon as possible after mixing for best flow and air bubble release from the rubber. Vacuum degassing helps to obtain bubble-free molds, but is
usually not necessary. Allow the rubber to cure at room temperature, 25°C / 77°F). Carefully remove the mold or cast product from the mould/mold after the demould/demoulding time has elapsed.
The final curing properties are obtained in approximately 24 hours after curing. Heat accelerates curing — low temperatures slow curing. Avoid curing in areas where the temperature is below 15°C.