RTV Silicone rubber HY-638 for concrete casting. Usage: RTV Silicone rubber HY638 is most suitable for concrete castings, cement statue, concrete pavers, GRC cement products, etc. with the advantages of good tensile strength, high tear strength, high temperature resistance, high duplication times and repeated use, etc. It is suitable for large products with detailed pattern, which is difficult to demould. This silicone rubber is one of the products with the highest use level in the production of concrete castings and the shrinkage is up to 2¡ë. Description: ¡¡¡¡ RTV-2 molding silicon rubber and silicone rubber are general called two-component room temperature vulcanization silicone rubber with excellent fluidity and good operational performance. Add curing agent of 2%-3% at the room temperature, the silicone rubber is still operational within 30 minutes, and in 2-3 hours, an elastic silicon mold will be obtained with resistance to deformation, high-temperature, acid and alkali and expansion. Standard datasheet: Model appearance viscosity (cs): 20000~26000 hardness (Ao): 32~36 Tensile Strength (kgf/c©O):45~51 Tear strength (kgf/©M): 20~25 Elongation (%): ¡Ý500 Mixing ratio (%):2~3 Operating time (h): 0.5 Curing time (h):2~4 Operation instruction for RTV-2 silicone rubber HY638#:¡¡¡¡ The product is white or red flowing liquid with general hardness of 22¡ª50A¡ãafter curing. If the customer wants to make large products and large size molds, the mold should be made of silicone rubber with high hardness. On the contrary, if the mold with fine and precision patterns, it should be made of silicon with low hardness. The amount of the curing agent depends on the actual requirements of the customer. If molds requiring fast drying and demould, more curing agent is needed; contrarily, if molds requiring slower drying and demould, less curing agent is needed. Notes: We do not recommend you to add silicone oil. If a special soft silicon mold or fine detailed and complex patterns products are required, 5%-10% silicone oil can be added to soften the mold for easy demould. The proportions and reactions of the curing agent and the silicon are listed as follows: ¡¡¡¡ Adding curing agent 1%, the silicone can still be operated within 2.5 hours and can be demoulded after 6-8 hours. ¡¡¡¡ Adding curing agent 2%, the silicone can still be operated within 50 minutes to 1 hour and can be demoulded after 2-3 hours. ¡¡¡¡ Adding curing agent 3%, the silicone can still be operated within 28 - 30 minutes and can be demoulded after 1.5-2 hours. Adding curing agent 4%, the silicone can still be operated within 10 - 15 minutes and can be demoulded. Any further information pls feel free to contact with Ms Alice ( Sales manager) TEL: 0086-755-89948294 Fax: 0086-755-89948030 Mobile: 0086-13510188049 E-mail: alice(at)szrl(dot)net Website: www(dot)szrl(dot)net