EZ-Brush™ – Brushable silicone for reusable vacuum bags
EZ-Brush™ Vac Bag Silicone is designed for demanding applications where efficiency and durability are essential. This platinum-cure (addition-cure), brushable silicone spreads easily even on vertical surfaces and cures quickly for use.
Preparation is key before starting. Both the materials and the model should be at room temperature to ensure consistent curing. Certain substances can interfere with the curing of addition-cure silicones, such as latex, tin-cure silicones, sulfur-containing clays, some wood surfaces, freshly cast polyester, and epoxy or polyurethane products. If the model contains any potentially inhibiting materials, a small test application 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—make sure it is fully dry before applying the silicone. Note: Platinum silicones are not compatible with sulfur-rich clays.
Mixing
Before use, Part B should be mixed thoroughly, as the platinum catalyst may settle during storage. Then, measure equal amounts of Part A and Part B by volume or weight (1:1 ratio). Mix the components thoroughly for at least 2–3 minutes, making sure to scrape the sides and bottom of the container. Air bubbles can be removed by degassing the mixture using a vacuum pump capable of pulling at least 1 bar. Silicone expands significantly during degassing, so use a container with ample space. Once the mixture levels out, continue degassing for another minute.
First Layer
Apply a thin first layer with a brush or spatula. At this stage, it is crucial to press the silicone into all surface details and corners of the mold. This layer serves as the bonding surface for the following layers. For complex shapes, having multiple people work simultaneously may be helpful.
Additional Layers
Wait approximately one hour until the first layer becomes tacky but is not fully cured. Then apply the next layer carefully to avoid disturbing the one beneath. Repeat this process 3–4 times. Each layer should be around 1.5 mm thick. The final silicone bag should be approximately 4.5–5 mm thick to achieve good mechanical strength and flexibility.
Curing and Demolding
Allow the silicone to cure for at least 3.5 hours at room temperature. Avoid temperatures below 18 °C, as they may slow down or prevent curing. Once cured, the mold can be carefully removed. The silicone vacuum bag is immediately ready for use.
Use and Storage
Once cured, the silicone bag is flexible (Shore A 20), durable, and long-lasting when used and stored properly. Its service life depends on the materials it is used with, frequency of use, and cleaning method. In some cases, a release agent may be required—especially when used with epoxy resins, as the silicone performs better with polyester resins.
After use, the mold should be cleaned with, for example, isopropyl alcohol and dried thoroughly. The best way to store it is on the original model in a cool, dry place. Avoid moisture, UV exposure, and stacking, as these can damage or deform the mold.
Why choose EZ-Brush™?
EZ-Brush™ offers a practical and long-lasting alternative to single-use vacuum bagging methods. It shortens production time, reduces process steps, and lowers long-term costs. The result is also higher quality. If your goal is to increase production efficiency and reduce material waste, EZ-Brush™ Vac Bag Silicone is a reliable choice.