RTV1000 Silicone Rubber
PRODUCT DESCRIPTION RTV1000 is a high tear resistant, high-strength RTV silicone rubber that was especially designed for casting solid polyurethane and polyurethane foam parts. It is also acceptable for casting polyester or epoxy parts. RTV1000 has the following advantages over other RTV silicones:
1. Extremely high tear strength. It is especially good for molds that must be flexed for part removal.
2. Low Shrinkage: Much lower shrinkage than most other commercially available RTV silicones. This is a particularly valuable property in the production of multi-piece molds that require exact registration to minimize the parting lines.
3. Excellent chemical resistance. RTV1000 exhibits extremely long mold life.
4. Excellent shelf-life characteristics. If stored in a clean and cool environment, molds may last up to 5 years. RTV1000 molds do retain dimensional stability over time.
5. Color-coded catalyst. The standard catalyst supplied with RTV1000 is colored BLUE so that the homogeneity in mixing can be determined by a uniform color of the mixed product. This property ensures that molds will not be lost due to improper mixing.
6. Excellent cure compatibility. The curing of RTV1000 is rarely inhibited, regardless of the type of clay, tape or wood used in the pattern or box.
7. Maximum cost effectiveness. Low RTV1000 cost along with longer mold life combine to yield more parts per mold dollar.
8. Low specific gravity means more molds per pound of RTV1000 which in turn means lower cost.
9. Accessory chemicals such as wood primer, aluminum primer, diluent (thinner), curing agent accelerator and compatible color concentrates broadens the versatility of this mold-making systems.
MIXING INSTRUCTIONS Proportion Part A and Part B in a ratio of 10 Parts A to 1 Part B by weight. Stir thoroughly either by hand or by mechanical mixer until a uniform color is achieved. Mix until all streaks of white disappear. If facilities permit, deaerate in a vacuum chamber at a minimum of 28 inches of mercury until material rises to approximately double the volume and collapses. Carefully pour rubber over the pattern and allow to cure for the required time. Water mist can sometimes help slow-curing rubber “catch-up” to normal cure time.
RELEASE AGENTS Silicone can adhere to many different materials, and precautions should be taken to prevent it from bonding with your original pattern and when casting parts in the mold. Before pouring the silicone into the mold box, be sure to lightly spray the pattern and mold box surface with Eager Plastics’ Pattern Release to prevent any bonding. If a parting mold (i.e., two-piece mold) is to be made, also use Pattern Release spray between layers of silicone. Porous surfaces need to be sealed with spray shellac or another suitable sealing agent prior to spraying with Pattern Release. After the mold has been separated from the pattern, apply a release agent to the inside of the mold prior to casting any parts for better mold life. Use Ease Release 200 if casting urethane and epoxy, unless parts are to be painted. Casting of wax does not require the use of a release agent. For other materials, please contact us for recommendations.
Typical Properties of RTV 1000 Separate Compounds & Mixtures
Base Rubber Slow (BLUE) Cat. Fast Cat. Ultra Fast Cat
Color White Dark Blue Pale blue Clear
Viscosity, cps 50,000 1,000 100
Specific Gravity 1.09 0.99 0.99
Working Time N.A. 1.5 hrs 6 min. 5-60 min
Cure time N.A. 16-24 hrs 2-3 hrs. 20 min-3 hrs
Shelf-life 6 months 6 months 6 months 6 months
Typical Properties of Cured RTV1000 Silicone Rubber (7 Day cure at 77°F and 50% relative humidity)
Hardness, Shore A Scale 23-28 23-28 0-25
Tensile Strength, psi 775 700
Elongation, % 300 280
Tear, die B lbs/in 105 100
Shrinkage, % 0.1 1.0
Cured Density, oz/cu in 0.67 0.68
ADDITIVES AND ACCESSORIES FOR RTV1000 SILICONE
RTV DILUENT THINNING AGENT is a low-viscosity silicone fluid. It lowers the viscosity of the mix and thins the RTV1000, making it more pourable. Normally 10% by weight is used, but it can also be used to much higher levels. At the 10% addition level, the sacrifice of physical properties is non-existent. In fact, the opposite is often reported; some properties, namely release, seem to be improved. Consequently, RTV Diluent is sometimes used as a release agent to improve release and extend mold life.
CURING AGENT ACCELERATOR is a clear amber fluid with a mild odor. This accelerator has a powerful effect on the curing speed. Small amounts have a dramatic effect. With the slow (BLUE) curing agent, a 1% addition of accelerator produces a 5 minute cure and 0.25% addition will produce a 2 hour cure. 0.25% is equivalent to 3 drops of accelerator per weight ounce, or 1.125 grams per pound of RTV1000 base rubber. The accelerator reduces pot life as well as cure time, so adjust the amount for best results.
RTV PRIMER will cause RTV1000 to bond to most porous surfaces such as wood. Primer can be brushed, sprayed or dipped. Pour RTV within one hour of applying primer.
THICKENING AGENT There is no known thickening agent for RTV silicones. Some success has been achieved by adding Cab-O-Sil to the mixture. If a thicker system is needed, try RTV184, which has a thixotropic activator, or one of our flexible brushable urethanes.
Warning: Uncured product may cause respiratory or skin irritation with possible sensitization. Use only with adequate ventilation. If skin contact occurs, wash thoroughly with soap and water. In case of eye contact, flood with water and call a physician. Use of gloves and face shield is recommended. This product should not be used near food or where prolonged skin contact may occur.
Disclaimer: This information is based on sources that we believe to be accurate. It is offered in good faith, but without guarantee, since conditions of use are beyond control. All risk of use are assumed by the user.