Product Information
SILICONE EZ-Brush Vac Bag Silicone 7,26 kg
EZ-Brush™ Vac Bag Silicone is a brushable, platinum-cure silicone developed for making reusable vacuum bags. It is easy to mix and apply. The mix ratio is 1A:1B by volume, and the material can be applied with a brush or spatula. The silicone is non-sagging, making it suitable for use on vertical surfaces as well.
Specifications
The working time is 30 minutes and the surface can be re-coated after one hour at room temperature. The silicone cures with virtually no shrinkage into a soft and flexible material (Shore 20A) with excellent elongation and tear strength. New silicone bags can be demolded after 3.5 hours and put into immediate use in production with polyester or epoxy resin systems. The material withstands temperatures up to 260 °C.
Compared to traditional vacuum bagging methods, EZ-Brush™ Vac Bag Silicone allows for the significantly faster production of ready-to-use silicone bags. This results in substantial savings in both time and labor. Since the bags are reusable, long-term material costs are also significantly reduced.
Shore Hardness (A) | 20 |
Mix Ratio (Volume) | 1:1 |
Pot Life (23°C) | 30 min |
Cure Time (23°C) | 3,5 h |
Temperature Resistance (min) | -53 °C |
Temperature Resistance (max) | 232 °C |
Shrinkage | <0.001 mm/mm |
Viscosity (cpc) | 20 000 |
Elongation (%) | 364 |
Color | Translucent Green |
Application
Before mixing, stir both components thoroughly, as some separation may occur during storage. Measure parts A and B in a 1:1 ratio by volume or weight. Mix thoroughly for 2–3 minutes, scraping the sides and bottom of the container to ensure complete mixing and prevent uneven curing.
Degassing is recommended. For best results, degas the mixture under vacuum before application. Use a vacuum pump capable of pulling at least 1 bar vacuum. Leave enough space in the container for expansion - silicone will rise, collapse and then settle. Continue vacuuming for about one more minute after the surface stabilizes.
Applying the Silicone
Apply the silicone in multiple thin layers (usually 3–4), each about 1.5 mm thick. Start from one section and work across the entire surface evenly. Let the first layer sit for about 1 hour or until it becomes tacky before applying the next layer. Repeat this process until a total thickness of at least 4.8 mm is reached.
Begin by applying silicone into detailed areas and recesses to ensure full coverage. Having a second person assist with brushing or spreading the silicone can significantly ease the process. Do not let any layer fully cure before adding the next one, as this may cause delamination.
Curing
Allow the silicone to cure at room temperature (23°C) for at least 3.5 hours before demolding. Do not cure below 18°C as this may slow down or prevent curing entirely.
Cure Inhibition: The curing of addition-cure silicones can be inhibited by certain materials, such as latex, tin-cure silicones, sulfur-containing clays, certain wood surfaces, fresh polyester castings, and some epoxy or polyurethane products. If compatibility is uncertain, a small test cast is recommended. Inhibition is indicated if the silicone remains tacky or fails to cure. Coating the model with a clear acrylic sealer can help prevent inhibition issues. Allow the sealer to dry completely before applying the silicone. Note: Platinum-cure silicone is not compatible with sulfur-rich clays.
Using and Storing the Finished Bag
Once fully cured, the silicone bag is durable and long-lasting when used and stored properly. Its lifespan depends on the type and frequency of use, as well as how it is cleaned. In some cases, a mold release agent may be necessary. Silicone bags generally perform better with polyester resins than with epoxy.
Clean the bag with isopropyl alcohol and dry it thoroughly before storage. Ideally, store the bag on the original model in a cool, dry place. Avoid moisture, UV light, and stacking to prevent deformation or damage.
Safety
Use in a well-ventilated area. Safety glasses, long-sleeved clothing, and only vinyl gloves - latex gloves can inhibit the curing of the silicone. Use and store the material at room temperature (approx. 23 °C). Higher temperatures will significantly reduce working and curing times as well as shelf life. Use the products as soon as possible, as they have a limited shelf life.