WEICON Silicone HT 300 Solvent-Free Liquid Gasket

WEICON Silicone HT 300 Solvent-Free Liquid Gasket is a silicone-based industrial adhesive solution designed for sealing and elastic bonding in joints exposed to high temperatures. Thanks to its moisture-curing acetate crosslinking system, it helps form a permanent gasket line between metal surfaces. Its solvent-free formulation supports controlled application and clean workmanship in assembly and maintenance processes. Its red color makes the application bead easier to visually inspect, contributing to process standardization.

High-temperature sealing approach with Silicone HT 300

This liquid gasket is developed for sealing under high-temperature conditions, with an aim for resistance to weathering, aging, and chemical influences. Its temperature resistance is stated as -40 °C to +280 °C, and it stands out with the possibility of use up to around +300 °C for short-term exposure. Its elastic structure supports the continuity of the gasket line in joints where thermal expansion–contraction and vibration-related micro-movements occur. The manufacturer is WEICON GmbH & Co. KG and the origin is Germany.

Chemical structure, curing principle, and core performance

The product is 1K polysiloxane (acetate) based and cures with ambient moisture to form an elastic sealing layer. With a density of approximately 1.18 g/cm³ and a paste-like consistency, it helps reduce sagging on vertical surfaces and makes controlled application easier. Since the curing speed is stated as 2–3 mm within the first 24 hours, process planning should take this into account for thick applications. With an elongation at break of around 300%, it offers an advantage in applications targeting flexibility and movement tolerance in the sealing line.

Strength values and operating limits

Because the skin formation time is about 8 minutes, completing assembly before skin formation helps achieve better wetting. Maximum gap closure is defined as 5 mm and maximum joint width as 25 mm, so joint geometry should be designed within these limits. Tensile strength is given as 2.5 N/mm² and Shore A hardness as 30±5, describing an elastic yet stable gasket character. Movement absorption is stated as a maximum of 15%; therefore, joint design should be evaluated separately for highly dynamic joints.

Standards, classifications, and process compatibility

Its building material class is stated as B2 according to DIN 4102, which can be a selection criterion especially in building/installation applications. The information that it is compatible with ISSA code 75.634.20/21 and MIL-A-46146 provides a brief reference supporting standardization in industrial maintenance and equipment applications. The product is developed to target good adhesion on surfaces such as steel, aluminum, glass, and ceramic; therefore, it can serve both as an industrial adhesive and a liquid gasket in many assemblies. If there are surface coatings, contamination, or special materials, the need for a primer should be evaluated according to application conditions.

Application method and industry use areas

Ensuring surfaces are clean and degreased before application directly determines performance for this type of silicone-based industrial adhesive solution. It is applied as a continuous bead using a cartridge gun or pneumatic gun, and the assembly should be completed before skin formation. It can be considered for sealing in high-heat areas such as industrial ovens, flue gas systems, heating installations, exhaust gas routing lines, and heating cabinets. In machine maintenance and repair, it offers an alternative to cut gaskets on metal mating surfaces, helping shorten assembly time and form the sealing line in a single step.