Weicon WEICONLOCK® AN 305-18 Anaerobic Flange Sealant

Weicon WEICONLOCK® AN 305-18 Anaerobic Flange Sealant is an anaerobic industrial adhesive and sealing product that works as a “liquid gasket” on flange surfaces and suitable joints. When the flange surfaces are assembled, it cures in the metal contact area to create a seal and helps reduce joint loosening. Thanks to its high-viscosity structure, the application bead can be applied in a more controlled way and offers an advantage especially when filling larger gaps. The product is manufactured in Germany by WEICON GmbH & Co. KG.

Working principle for flange sealing with WEICONLOCK AN 305-18
This product works by being applied as a continuous bead on one flange face, followed by quickly assembling the parts. Because it is an anaerobic system, curing takes place where oxygen is excluded between metal surfaces, creating a sealing effect along the joint line. Since it is positioned as a high-strength grade, it is suitable for applications that target “hard to disassemble” joints during service and, in this respect, also contributes to joint stability as an industrial adhesive. Its red color makes it easier to visually follow the application line and helps carry out the process in a more controlled manner.

Technical performance range and strength character
The Brookfield viscosity range at 25 °C is specified as 80,000–500,000 mPa·s, indicating a thick structure that reduces the tendency to run on flange surfaces. A maximum gap-bridging value of 0.5 mm supports sealing needs in flange joints with higher tolerances. With breakaway torque stated as 12–18 Nm and prevailing torque as 18–24 Nm for threaded connections, a high-strength industrial adhesive behavior is expected. Temperature resistance is given as -60 °C to +200 °C, providing flexibility for use in housing and enclosure joints exposed to variable temperatures. Achieving initial strength within 10–20 minutes at room temperature and full strength within 3–6 hours offers a clear time window for maintenance and commissioning planning.

Application method and surface preparation
For best performance, surfaces are recommended to be clean and free from oil; however, it is stated that lightly oily surfaces can be tolerated. Application is carried out directly and evenly from the package; avoiding direct contact between the dosing nozzle and metal helps reduce the risk of unwanted curing inside the container. For flange sealing, a continuous bead is applied to one side of the flange, then the parts are quickly assembled and tightened; this step is critical for proper spread before skin formation. For sealing applications such as pipe threads, the product is applied to the thread in circular movements and the connection is tightened to the desired alignment. In serial applications, manual or automatic dosing can help apply the same quantity and improve repeatability of results.

Industry applications and key advantages
This industrial adhesive can be used for sealing flange surfaces in gearbox and motor housings, pump/housing joints, compressor connections, and general machine maintenance. In process lines and flange connections, it provides a practical “liquid gasket” solution for teams aiming to reduce leak risk and shorten assembly time. High viscosity supports controlled application on vertical or hard-to-reach areas, while the gap-bridging approach up to 0.5 mm can be advantageous in more challenging tolerance scenarios. Because it is a high-strength grade, the disassembly plan should be defined in advance during service; if needed, disassembly methods should be aligned with equipment procedures. With proper surface preparation and the correct application bead, it is positioned as a reliable solution that targets both sealing and joint stability at the same time.